Apache Axis2/C HTTP/2 JSON and REST with Apache httpd User's Guide

Overview

This guide will help you get started with Axis2/C HTTP/2 transport and JSON via REST, using Apache httpd with mod_h2 and mod_ssl! It gives a detailed description on how to write HTTP/2 optimized JSON based REST Web services for enterprise applications, including big data processing, user authentication, and security demonstrations.

Port from Axis2/Java Spring Boot: This guide is a complete port of the Axis2/Java Spring Boot demonstration services, replacing Spring Boot embedded server with Apache httpd for production deployment with enhanced performance and security.

New in Axis2/C 2.0: Complete HTTP/2 transport implementation with enterprise capabilities, streaming optimization for large JSON payloads, authentication services, XSS protection demonstrations, and production-ready performance enhancements using Apache httpd as the application server.

✅ Verified Testing: This guide has been tested and verified to work on Ubuntu 25.10 with Apache httpd and mod_h2 support.

🔧 Critical Configuration: HTTPS Virtual Hosts MUST include <Location /services> directive inside <VirtualHost *:443> blocks. Without this, Axis2/C services will fail with routing errors and no debug messages will appear in logs.

🚀 TL;DR - Why C Programmers Choose Axis2/C HTTP/2

💾 Memory Efficiency: 240MB peak for 50MB JSON vs JVM heap overhead ⚡ Native Speed: 26.56 MB/s JSON throughput with zero JVM warm-up 🏗️ Build Time: 162% faster compilation (13:31 min → <5 min) 🎯 Latency: 30% reduction (60ms → 42ms) vs HTTP/1.1 baseline 🔗 Multiplexing: 50% overhead reduction with HTTP/2 connection reuse 📊 Scalability: 10/10 concurrent streams processed in 2ms total 🛠️ Deployment: Single .so library vs WAR + application server stack

Bottom Line: Native C performance with enterprise-grade HTTP/2 JSON processing, measured and documented.

Important Note about JSON Processing Architecture:

Axis2/C 2.0 implements a Dual JSON Architecture that separates HTTP/1.1 and HTTP/2 JSON processing:

• HTTP/1.1 Transport: Uses json-c library with optional XML/SOAP compatibility for legacy applications
• HTTP/2 Transport: Uses optimized json-c library with zero XML/SOAP dependencies for maximum performance

This pure json-c approach for both transports provides:

• ✅ No SOAP/XML overhead: Direct JSON processing using native json-c objects
• ✅ Memory efficiency: 60-80% less memory usage compared to XML-based processing
• ✅ Performance gains: 30-40% faster JSON processing for large payloads (50MB+)
• ✅ Streaming optimization: Native support for HTTP/2 flow control and streaming

Critical Build Requirement: Despite HTTP/2 using pure json-c (bypassing the traditional AXIS2_JSON_ENABLED framework), the --enable-json configure flag is REQUIRED because:

• PKG-CONFIG Integration: Sets up JSON_CFLAGS and JSON_LIBS build variables
• Library Detection: Ensures json-c development headers and libraries are available
• HTTP/2 Compilation: HTTP/2 tests and utilities depend on these build variables

In the “configure” examples both flags are essential:

./configure --enable-http2 --enable-json  # Both required for HTTP/2

---

Demonstration Services

This guide covers five fully implemented service demonstrations:

1. BigDataH2Service: HTTP/2 big data processing with streaming optimization
2. LoginService: User authentication with JWT token generation
3. TestwsService: XSS protection demonstration with HTML encoding
4. CameraControlService: Generic camera control with SFTP file transfer using user-implementable stub functions
5. FinancialBenchmarkService: Financial computation benchmarks demonstrating native C performance for O(n²) matrix operations

Stateless Architecture: All services are stateless—each request is processed independently without HTTP cookies or server-side session storage. This enables horizontal scaling where any server instance can handle any request.

⚠️ Protocol Requirement: These services are HTTP/2-only for performance optimization. HTTP/1.1 requests will receive HTTP 426 “Upgrade Required” responses. Always use curl --http2 for testing.

More documentation concerning Axis2/C and JSON can be found in the HTTP/2 JSON Architecture and HTTP/2 Configuration.

🔗 Related Technical Documentation

For comprehensive technical architecture and performance analysis, see Axis2/C HTTP/2 Pure JSON Architecture - Migration State which provides:

• Detailed performance comparison vs Axis2/Java (memory, speed, build time)
• HTTP/2 transport architecture and multiplexing analysis
• JSON-C integration patterns and optimization techniques
• Migration strategies from XML/SOAP to pure JSON
• Comprehensive benchmarking methodology and results

This user guide focuses on practical implementation and deployment, while the migration document provides deep technical insights and performance data.

Introduction

This user guide is written for Axis2/C 2.0.0, which introduces comprehensive HTTP/2 support and enterprise web service capabilities. This guide covers building from source and deploying the demonstration services.

The Axis2/C source can be obtained from the official Apache Git repository or as a source distribution download. For production deployments, we recommend using the tagged v2.0.0 release. The Installation Guide provides additional build instructions for various platforms.

The source code for this guide provides a complete Apache httpd configuration and Axis2/C service implementation for enterprise big data processing with HTTP/2 optimization.

Please note that Axis2/C is an open-source effort. If you feel the code could use some new features or fixes, please get involved and lend us a hand! The Axis developer community welcomes your participation.

Let us know what you think! Send your feedback to “c-user@axis.apache.org”. Kindly prefix the subject of the mail with [Axis2C].

HTTP/2 Transport Features

Axis2/C 2.0 introduces a complete HTTP/2 transport implementation designed for enterprise big data processing requirements. The HTTP/2 transport provides significant performance improvements over HTTP/1.1, especially for large JSON payloads and concurrent requests.

Key HTTP/2 Benefits

• Connection Multiplexing: Process multiple requests over a single connection, reducing connection overhead by up to 80% (from 50 connections to 10 multiplexed connections)
• Streaming Optimization: Memory-efficient processing of large JSON payloads (50MB+) with 20% reduction in memory usage
• Enhanced Performance: 30% reduction in request latency and 40% improvement in JSON processing throughput for enterprise workloads
• Memory Management: Adaptive flow control and memory pressure detection for operation within 2GB heap constraints
• Security: HTTPS-only enforcement (RFC 7540 compliance) with TLS 1.2+ and ALPN support. See HTTP/2 and JSON Security for JSON parser limits, payload size controls, and CVE mitigations.

HTTP/2 Processing Modes

The HTTP/2 transport automatically selects the optimal processing mode based on payload size:

• Standard Processing (<10MB): Regular HTTP/2 transport with multiplexing benefits
• Multiplexing Optimization (10-50MB): Enhanced concurrent processing with connection multiplexing and flow control
• Streaming Optimization (50MB+): Memory-efficient streaming with chunked processing and adaptive windowing for enterprise big data requirements

Enterprise Big Data Support

The HTTP/2 transport is specifically optimized for enterprise big data processing:

• Large Payload Support: Tested with JSON payloads up to 100MB+
• Memory Constraints: Designed for 2GB heap environments with adaptive memory management
• Concurrent Processing: Support for multiple simultaneous large dataset operations
• Performance Monitoring: Built-in metrics collection for throughput and memory usage

Incremental Buffer Allocation

Axis2/C uses an intelligent incremental buffer growth strategy that optimizes memory usage across diverse workloads - from IoT devices with tiny payloads to enterprise systems with multi-megabyte JSON:

Initial Size	Growth Strategy	Maximum	Use Case
64KB	Doubles on demand	10MB	Adapts to actual payload size

Memory Efficiency by Payload Size:

Payload Type	Actual Size	Buffer Allocated	vs Static 10MB
IoT/Camera	~24 bytes	64KB	160x smaller
Medium JSON	~50KB	64KB	160x smaller
Large portfolio	~235KB	256KB	40x smaller
Enterprise	~5MB	8MB	1.25x smaller

This approach ensures:

• IoT efficiency: Camera control payloads (~24 bytes) use only 64KB instead of 10MB
• Enterprise support: 500-asset financial portfolios (~5MB) are fully supported
• No configuration needed: Buffer grows automatically based on actual data

Implementation Note: Uses standard C malloc/realloc for reliable buffer growth, with final copy to AXIS2-managed memory for consistent cleanup.

Defense in Depth: Request Limits

Axis2/C implements a multi-layer security architecture where Apache httpd enforces request limits before payloads reach the C code. This provides protection against:

• Memory exhaustion attacks: Large payloads rejected at TCP level
• Slowloris/slow-read attacks: Timeout enforcement at Apache level
• Integer overflow exploits: Size limits enforced before arithmetic operations

Security Layers:

Layer	Directive	Enforced By	Failure Response
1. Apache	LimitRequestBody	httpd (before mod_axis2)	HTTP 413
2. Axis2/C	max_buffer (10MB)	JSON processor with overflow checks	JSON error 413
3. Service	maxJSONPayloadSize	services.xml configuration	Application error

Recommended Apache Configuration (in httpd.conf):

Convenience: A complete httpd.conf with these limits pre-configured is available at docs/userguide/httpd.conf. Copy it to /usr/local/apache2/conf/ to deploy.

# Global default: 10MB max request body (matches Axis2/C max_buffer)
LimitRequestBody 10485760

# Limit request line (URL + method + protocol) - prevents long URL attacks
LimitRequestLine 8190

# Limit total header fields - prevents header flooding
LimitRequestFields 100

# Limit individual header size - prevents header overflow attacks
LimitRequestFieldSize 8190

# Per-service overrides for different workloads:
<Location /services/CameraControlService>
    # IoT endpoints need minimal payloads
    LimitRequestBody 65536
</Location>

<Location /services/FinancialBenchmarkService>
    # Enterprise payloads up to 10MB
    LimitRequestBody 10485760
</Location>

<Location /services/BigDataH2Service>
    # Big data service - allow larger payloads (50MB)
    LimitRequestBody 52428800
</Location>

Key Security Benefit: If an attacker sends a 100MB payload:

1. Apache rejects at TCP level before mod_axis2 is invoked
2. No memory allocated, no CPU spent parsing malicious data
3. Clean HTTP 413 response with minimal server resources consumed

Integer Overflow Protection: The Axis2/C JSON processor includes explicit checks for:

• Buffer arithmetic underflow (current_size - total_read - 1)
• Read size overflow before addition (bytes_read > max_buffer - total_read)
• Safe buffer doubling (current_size > max_buffer / 2 check before multiply)
• Allocation size validation (total_read + 1 overflow check)

Getting Started for Beginners

This comprehensive step-by-step guide will walk you through building and deploying all three C web services from scratch, even if you're new to Axis2/C development.

Prerequisites and Dependencies

Before starting, ensure your system has all required dependencies installed:

Ubuntu/Debian Systems:

# Update package list
sudo apt-get update

# Install build tools and dependencies
sudo apt-get install -y \
    build-essential \
    autotools-dev \
    autoconf \
    automake \
    libtool \
    pkg-config \
    git

# Install Apache and development headers with HTTP/2 + SSL/TLS support
sudo apt-get install -y \
    apache2 \
    apache2-dev \
    libapache2-mod-h2 \
    libssl-dev \
    libcurl4-openssl-dev \
    openssl

# Install JSON-C library
sudo apt-get install -y \
    libjson-c-dev \
    libjson-c5

# Install additional dependencies for Axis2/C
sudo apt-get install -y \
    libxml2-dev \
    libcurl4-openssl-dev \
    uuid-dev \
    zlib1g-dev

RedHat/CentOS/Fedora Systems:

# Update package list
sudo dnf update  # or 'yum update' on older systems

# Install build tools and dependencies
sudo dnf install -y \
    gcc \
    gcc-c++ \
    make \
    autoconf \
    automake \
    libtool \
    pkg-config \
    git

# Install Apache and development headers with HTTP/2 + SSL/TLS support
sudo dnf install -y \
    httpd \
    httpd-devel \
    mod_h2 \
    mod_ssl \
    openssl \
    openssl-devel

# Install JSON-C library
sudo dnf install -y \
    json-c-devel

# Install additional dependencies for Axis2/C
sudo dnf install -y \
    libxml2-devel \
    libcurl-devel \
    libuuid-devel \
    zlib-devel

Quick HTTP/2 Support Test

Before compiling Apache from source, test if your system Apache already has HTTP/2 support:

# Quick test - does Apache have mod_h2 available?
echo "🔍 Testing Apache HTTP/2 support on your system..."

# Test 1: Check if Apache is installed
{ command -v apache2 >/dev/null 2>&1 || command -v httpd >/dev/null 2>&1; } && echo "✅ Apache installation found" || { echo "❌ No Apache installation found"; echo "   Install Apache first: sudo apt install apache2"; return 1 2>/dev/null || echo "Please install Apache before continuing"; }

# Test 2: Check if mod_h2 module file exists
{ ls /usr/lib/apache2/modules/mod_h2.so 2>/dev/null || ls /usr/lib*/httpd/modules/mod_h2.so 2>/dev/null; } && { echo "✅ mod_h2.so found - HTTP/2 module is available!"; echo "   You can use system Apache (skip source compilation)"; } || echo "❌ mod_h2.so not found - HTTP/2 module missing"

# Test 3: Try enabling mod_h2 (safe test)
command -v a2enmod >/dev/null 2>&1 && { sudo a2enmod h2 2>/dev/null && { echo "✅ mod_h2 enabled successfully!"; echo "   Your system Apache supports HTTP/2"; sudo a2dismod h2 2>/dev/null; } || echo "❌ Cannot enable mod_h2 - module not available"; } || echo "⚠️ a2enmod not available - cannot test module enabling"

# Test 4: Check what HTTP/2 related modules exist
echo ""
echo "Available HTTP/2 related modules:"
find /usr/lib*/apache2/modules /usr/lib*/httpd/modules -name "*h2*" -o -name "*http2*" 2>/dev/null || echo "None found"

echo ""
echo "📋 RECOMMENDATION:"
ls /usr/lib*/apache2/modules/mod_h2.so /usr/lib*/httpd/modules/mod_h2.so 2>/dev/null >/dev/null && { echo "✅ Use system Apache - HTTP/2 support is available"; echo "   Continue with Step 1 Option A"; } || { echo "❌ Compile Apache from source - no HTTP/2 support in system package"; echo "   Use Step 0 below, then Step 1 Option B"; }

Run this test first to save time!

---

Compiling Apache httpd from Source with HTTP/2 Support

When to use this approach:

• Your distribution lacks mod_h2 support (like Ubuntu 25.10)
• You need the latest Apache features
• You want full control over Apache compilation options
• You're working with Apache projects and expect to overcome such hurdles

⚠️ Important: This will install Apache to /usr/local/apache2 to avoid conflicts with system packages.

Step 0: Compile Apache httpd from Source

Install build dependencies:

# Ubuntu/Debian
sudo apt-get install -y build-essential libtool-bin \
    libpcre3-dev libssl-dev libnghttp2-dev \
    libexpat1-dev libapr1-dev libaprutil1-dev \
    wget

# RedHat/CentOS/Fedora
sudo dnf install -y gcc gcc-c++ make libtool \
    pcre-devel openssl-devel libnghttp2-devel \
    expat-devel apr-devel apr-util-devel \
    wget

Download and compile Apache httpd 2.4.64 (or latest) with HTTP/2:

# Create build directory
mkdir -p ~/apache-build
cd ~/apache-build

# Download Apache httpd source, always get latest
wget https://archive.apache.org/dist/httpd/httpd-2.4.64.tar.gz
tar -xzf httpd-2.4.64.tar.gz
cd httpd-2.4.64

# Configure with HTTP/2 support
./configure \
    --prefix=/usr/local/apache2 \
    --enable-so \
    --enable-ssl \
    --enable-http2 \
    --enable-headers \
    --enable-rewrite \
    --with-ssl \
    --with-nghttp2 \
    --enable-mods-shared=all

# Compile (use all CPU cores)
make -j$(nproc)

# Install
sudo make install

# Create systemd service (FIXED: Use Type=simple with -D FOREGROUND)
sudo tee /etc/systemd/system/apache2-custom.service << 'EOF'
[Unit]
Description=Apache HTTP Server (Custom Build)
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/apache2/bin/httpd -D FOREGROUND
ExecReload=/usr/local/apache2/bin/httpd -k graceful
KillMode=mixed
PrivateTmp=true
Environment=APACHE_RUN_DIR=/usr/local/apache2/var/run

[Install]
WantedBy=multi-user.target
EOF

# Set up runtime directories
sudo mkdir -p /usr/local/apache2/var/run
sudo chown www-data:www-data /usr/local/apache2/var/run 2>/dev/null || \
sudo chown apache:apache /usr/local/apache2/var/run 2>/dev/null || \
sudo chown $(whoami):$(whoami) /usr/local/apache2/var/run

# Fix ServerName to prevent AH00558 warning (HTTP/2 requires HTTPS)
sudo sed -i 's/#ServerName www.example.com:80/ServerName localhost:443/' /usr/local/apache2/conf/httpd.conf

# Enable HTTP/2 modules (uncomment and add missing modules)
sudo sed -i 's/#LoadModule http2_module modules\/mod_http2.so/LoadModule http2_module modules\/mod_http2.so/' /usr/local/apache2/conf/httpd.conf
sudo sed -i 's/#LoadModule ssl_module modules\/mod_ssl.so/LoadModule ssl_module modules\/mod_ssl.so/' /usr/local/apache2/conf/httpd.conf

# Enable mod_proxy (required dependency for proxy_http2)
sudo sed -i 's/#LoadModule proxy_module modules\/mod_proxy.so/LoadModule proxy_module modules\/mod_proxy.so/' /usr/local/apache2/conf/httpd.conf

# Add proxy_http2 module (usually not in default config)
echo 'LoadModule proxy_http2_module modules/mod_proxy_http2.so' | sudo tee -a /usr/local/apache2/conf/httpd.conf

# Add HTTP/2 protocol configuration
sudo tee -a /usr/local/apache2/conf/httpd.conf << 'EOF'

# HTTP/2 Protocol Configuration
Protocols h2 h2c http/1.1

# HTTP/2 Settings
H2Direct on
H2Push on
H2PushPriority *                       after
H2PushPriority text/css                before
H2PushPriority image/jpeg              after   32
H2PushPriority image/png               after   32
H2PushPriority application/javascript  interleaved

EOF

# Create SSL certificate for HTTPS (required for HTTP/2)
sudo mkdir -p /usr/local/apache2/conf/ssl
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
  -keyout /usr/local/apache2/conf/ssl/apache-selfsigned.key \
  -out /usr/local/apache2/conf/ssl/apache-selfsigned.crt \
  -subj "/C=US/ST=Test/L=Test/O=Test/OU=Test/CN=localhost"

# Add SSL Virtual Host configuration
sudo tee -a /usr/local/apache2/conf/httpd.conf << 'EOF'

# SSL Configuration for HTTPS
Listen 443 ssl
<VirtualHost *:443>
    ServerName localhost:443
    DocumentRoot /usr/local/apache2/htdocs

    SSLEngine on
    SSLCertificateFile /usr/local/apache2/conf/ssl/apache-selfsigned.crt
    SSLCertificateKeyFile /usr/local/apache2/conf/ssl/apache-selfsigned.key

    # Enable HTTP/2 for this virtual host
    Protocols h2 http/1.1

    # CRITICAL: Axis2/C Location directive must be inside HTTPS virtual host
    # Without this, /services/* requests won't reach mod_axis2
    <Location /services>
        SetHandler axis2_module
    </Location>

    # Enable JSON content type handling for HTTPS
    <LocationMatch "^/services/.*">
        Header always set Access-Control-Allow-Origin "*"
        Header always set Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS"
        Header always set Access-Control-Allow-Headers "Content-Type, Authorization, Accept"
    </LocationMatch>
</VirtualHost>

EOF

# IMPORTANT: Configuration Troubleshooting Note
#
# The above configuration fixes a critical issue where HTTPS/HTTP2 requests
# to /services/* would not reach mod_axis2. This happens because:
#
# 1. HTTPS requests go to the <VirtualHost *:443> block
# 2. If Axis2 <Location /services> is only in global config, virtual host doesn't inherit it
# 3. Result: mod_axis2 never gets called, requests fail with routing errors
#
# Symptoms of this issue:
# - HTTP/1.1 works over HTTP but fails over HTTPS
# - No debug messages from mod_axis2 in Apache error logs
# - SOAP faults or 404 errors for /services/* requests over HTTPS

# Test configuration before starting
sudo /usr/local/apache2/bin/httpd -t

# Enable and start custom Apache
sudo systemctl daemon-reload
sudo systemctl enable apache2-custom
sudo systemctl start apache2-custom

# Verify HTTP/2 module is available
/usr/local/apache2/bin/httpd -M | grep http2 && echo "✅ HTTP/2 modules available" || echo "❌ HTTP/2 modules missing"

# Check apache2-custom service status
systemctl status apache2-custom --no-pager

🔧 Apache Startup Troubleshooting

# Check service status
systemctl status apache2-custom -n 50

# View detailed logs
journalctl -xeu apache2-custom.service

# Test configuration syntax
sudo /usr/local/apache2/bin/httpd -t

**Verify Apache is working correctly:**
```bash
# Test basic HTTPS connectivity (HTTP/2 requires TLS)
curl -k -I https://localhost

# Test HTTP/2 support over HTTPS
curl -k --http2 -I https://localhost

# Check loaded modules
/usr/local/apache2/bin/httpd -M | grep -E "(http2|ssl|rewrite)"

Update PATH and configuration:

# Add custom Apache to PATH
echo 'export PATH="/usr/local/apache2/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

# Verify installation
httpd -v
httpd -M | grep -E "(h2|ssl|rewrite)"

Configure Apache for Axis2/C (adjust paths):

• Use /usr/local/apache2/conf/httpd.conf instead of /etc/apache2/apache2.conf
• Use /usr/local/apache2/bin/httpd instead of apache2ctl
• Use /usr/local/apache2/modules/ for module paths

🚀 Quick Setup: Complete httpd.conf

For the fastest setup, use the complete pre-configured httpd.conf file from this user guide at location: docs/userguide/httpd.conf

# Copy the complete HTTP/2 + Axis2/C configuration
sudo cp ${AXIS2C_HOME}/docs/userguide/httpd.conf /usr/local/apache2/conf/httpd.conf

# Generate SSL certificates (required for HTTPS)
sudo mkdir -p /usr/local/apache2/conf/ssl
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
    -keyout /usr/local/apache2/conf/ssl/apache-selfsigned.key \
    -out /usr/local/apache2/conf/ssl/apache-selfsigned.crt \
    -subj "/C=US/ST=Test/L=Test/O=Axis2C/CN=localhost"

# Create required directories
sudo mkdir -p /usr/local/axis2c/services
sudo mkdir -p /usr/local/axis2c/modules

# Start Apache
sudo systemctl restart apache2-custom

This pre-configured file includes:

• ✅ HTTP/2 protocol support (mod_http2, mod_proxy_http2)
• ✅ Axis2/C module integration
• ✅ SSL/TLS configuration for HTTPS
• ✅ Service location handlers (/services, /rest)
• ✅ Security headers and HTTPS-only enforcement

Alternatively, follow the manual configuration steps below:

Step 1: Configure Apache httpd for HTTP/2

Set up Apache httpd with HTTP/2 support first - this ensures that the curl verification tests in Step 3 will work properly after building Axis2/C in Step 2.

Choose Your Apache Setup:

Option A: System Apache (if mod_h2 is available)

# Install HTTP/2 dependencies and system Apache
sudo apt-get update
sudo apt-get install -y libjson-c-dev libnghttp2-dev apache2-dev uuid-dev
sudo apt-get install -y apache2 openssl

# For RedHat/CentOS/Fedora:
# sudo dnf install -y json-c-devel libnghttp2-devel httpd-devel libuuid-devel
# sudo dnf install -y httpd openssl

# Create required directories for Axis2/C
sudo mkdir -p /usr/local/axis2c
sudo mkdir -p /var/log/axis2c
sudo chown www-data:www-data /var/log/axis2c

Option B: Custom-Compiled Apache (recommended for Ubuntu 25.10)

# If you completed Step 0 above, verify your custom Apache is running:
systemctl status apache2-custom
/usr/local/apache2/bin/httpd -M | grep http2

# Create required directories for Axis2/C
sudo mkdir -p /usr/local/axis2c
sudo mkdir -p /var/log/axis2c
sudo chown www-data:www-data /var/log/axis2c 2>/dev/null || sudo chown $(whoami):$(whoami) /var/log/axis2c

Create Apache HTTPS configuration for HTTP/2:

IMPORTANT: HTTP/2 requires HTTPS (TLS encryption). Modern browsers and the HTTP/2 specification mandate secure connections, so this configuration is HTTPS-only.

Custom Apache Build (Recommended for /usr/local/apache2):

# Copy the pre-configured httpd.conf with defense-in-depth limits
sudo cp /home/robert/repos/axis-axis2-c-core/docs/userguide/httpd.conf /usr/local/apache2/conf/httpd.conf

# Create SSL directory and certificates
sudo mkdir -p /usr/local/apache2/conf/ssl
sudo openssl req -new -x509 -days 365 -nodes \
  -out /usr/local/apache2/conf/ssl/apache-selfsigned.crt \
  -keyout /usr/local/apache2/conf/ssl/apache-selfsigned.key \
  -subj "/CN=localhost/O=Axis2C/C=US"

# Set proper permissions
sudo chmod 600 /usr/local/apache2/conf/ssl/apache-selfsigned.key
sudo chmod 644 /usr/local/apache2/conf/ssl/apache-selfsigned.crt

# Test configuration
/usr/local/apache2/bin/apachectl configtest

# Start Apache (or use systemd service if configured)
sudo /usr/local/apache2/bin/apachectl start

# Verify HTTP/2 is working
curl -k -I --http2 https://localhost/

Note: The httpd.conf includes defense-in-depth request limits, per-service payload limits, and security headers. See the “Defense in Depth” section above for details.

Ubuntu/Debian Systems (using system Apache):

# Create the HTTPS-only configuration file
sudo tee /etc/apache2/sites-available/axis2-services.conf << 'EOF'
# Load required modules for HTTP/2 + HTTPS
LoadModule h2_module /usr/lib/apache2/modules/mod_h2.so
LoadModule ssl_module /usr/lib/apache2/modules/mod_ssl.so
LoadModule headers_module /usr/lib/apache2/modules/mod_headers.so
LoadModule axis2_module /usr/local/axis2c/lib/libmod_axis2.so

# Axis2/C Configuration (standard Unix paths)
Axis2RepoPath /usr/local/axis2c
Axis2LogFile /var/log/axis2c/axis2.log
Axis2LogLevel info

# HTTP/2 Configuration (requires HTTPS)
<IfModule mod_h2.c>
    # HTTP/2 performance settings for enterprise big data
    H2WindowSize 65536
    H2MaxWorkers 256
    H2MaxSessionStreams 100
    H2StreamMaxMemSize 104857600
    H2StreamTimeout 300

    # Security: HTTP/2 only over TLS 1.2+
    H2ModernTLSOnly on
    H2Upgrade off
    H2Direct on
</IfModule>

# HTTPS Virtual Host (HTTP/2 enabled)
<VirtualHost *:443>
    ServerName localhost:443
    # HTTP/2 first, HTTP/1.1 fallback
    Protocols h2 http/1.1

    # SSL Configuration for HTTP/2
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/axis2-server.crt
    SSLCertificateKeyFile /etc/ssl/private/axis2-server.key

    # TLS 1.2+ required for HTTP/2
    SSLProtocol -all +TLSv1.2 +TLSv1.3

    # Modern cipher suites for HTTP/2
    SSLCipherSuite ECDHE+AESGCM:ECDHE+CHACHA20:DHE+AESGCM:DHE+CHACHA20:!aNULL:!MD5:!DSS
    SSLHonorCipherOrder off

    # ALPN for HTTP/2 negotiation
    SSLUseStapling on
    SSLStaplingCache shmcb:/tmp/stapling_cache(128000)

    # Security headers for HTTPS-only deployment
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
    Header always set X-Content-Type-Options nosniff
    Header always set X-Frame-Options DENY
    Header always set Content-Security-Policy "upgrade-insecure-requests"

    # Axis2/C Services (HTTPS required)
    <Location /services>
        SetHandler axis2_module
        SSLRequireSSL
        # Force HTTPS for all service requests
        Header always set Strict-Transport-Security "max-age=31536000"
    </Location>

    # Service-specific configurations
    <Location /services/BigDataH2Service>
        Header always set Cache-Control "no-cache, no-store, must-revalidate"
    </Location>

    <Location /services/LoginService>
        Header always set X-XSS-Protection "1; mode=block"
        Header always set Content-Security-Policy "default-src 'self'"
    </Location>

    <Location /services/TestwsService>
        Header always set X-XSS-Protection "1; mode=block"
        Header always set Content-Security-Policy "default-src 'self'; script-src 'none'"
    </Location>
</VirtualHost>
EOF

# Enable the site and required modules
sudo a2ensite axis2-services

# Enable SSL and headers modules (standard modules)
sudo a2enmod ssl
sudo a2enmod headers

# Enable HTTP/2 module (REQUIRED for this guide)
# Try system Apache first, then custom Apache
command -v a2enmod >/dev/null 2>&1 && { sudo a2enmod h2 2>/dev/null && echo "✅ HTTP/2 module enabled successfully (system Apache)" || { echo "❌ System Apache mod_h2 module not available"; echo ""; echo "🔧 SOLUTIONS:"; echo "1. Use custom-compiled Apache (Step 0 above)"; echo "2. Install from Ondrej's PPA: sudo add-apt-repository ppa:ondrej/apache2"; echo "3. Use Ubuntu 24.04 LTS (has proper mod_h2 support)"; echo ""; echo "❌ SETUP FAILED: Cannot continue without mod_h2"; return 1 2>/dev/null || echo "Please fix mod_h2 issue above before continuing"; }; } || { command -v /usr/local/apache2/bin/httpd >/dev/null 2>&1 && { /usr/local/apache2/bin/httpd -M | grep -q h2 && { echo "✅ HTTP/2 modules available in custom Apache build"; echo "   mod_h2 and mod_http2 are compiled into your custom Apache"; } || { echo "❌ Custom Apache was compiled without HTTP/2 support"; echo "   Re-run Step 0 with --enable-http2 --with-nghttp2"; return 1 2>/dev/null || echo "Please recompile Apache with HTTP/2 support"; }; } || { echo "❌ No Apache installation found with HTTP/2 support"; echo "   Install system Apache or compile from source (Step 0)"; return 1 2>/dev/null || echo "Please install Apache before continuing"; }; }

# Create SSL certificates for HTTP/2 testing
# HTTP/2 requires valid TLS certificates - self-signed for development only
sudo openssl req -new -x509 -days 365 -nodes \
  -out /etc/ssl/certs/axis2-server.crt \
  -keyout /etc/ssl/private/axis2-server.key \
  -config <(
    echo '[dn]'
    echo 'CN=localhost'
    echo 'C=US'
    echo 'ST=State'
    echo 'L=City'
    echo 'O=Organization'
    echo '[req]'
    echo 'distinguished_name = dn'
    echo 'req_extensions = v3_req'
    echo '[v3_req]'
    echo 'keyUsage = keyEncipherment, dataEncipherment'
    echo 'extendedKeyUsage = serverAuth'
    echo 'subjectAltName = @alt_names'
    echo '[alt_names]'
    echo 'DNS.1 = localhost'
    echo 'IP.1 = 127.0.0.1'
    echo 'IP.2 = ::1'
  )

# Set proper permissions (critical for security)
sudo chmod 600 /etc/ssl/private/axis2-server.key
sudo chmod 644 /etc/ssl/certs/axis2-server.crt

# Verify certificate for HTTP/2 compatibility
echo "🔒 Verifying SSL certificate for HTTP/2..."
openssl x509 -in /etc/ssl/certs/axis2-server.crt -text -noout | grep -E "(Subject Alternative Name|DNS:|IP:)"

# Test Apache configuration
sudo apache2ctl configtest

# If test passes, start/restart Apache for HTTPS/HTTP/2 service
echo "🔄 Starting Apache httpd with HTTP/2 support..."
sudo systemctl is-active --quiet apache2 && {
    sudo systemctl restart apache2
    echo "✅ Apache restarted successfully"
} || {
    sudo systemctl start apache2
    echo "✅ Apache started successfully"
}

# Enable Apache to start on boot
sudo systemctl enable apache2

# Check Apache status
sudo systemctl status apache2 --no-pager

# Verify HTTP/2 is working
echo "🚀 Testing HTTP/2 connectivity..."
curl -k -I --http2 https://localhost/

RedHat/CentOS/Fedora Systems (using system Apache):

# Create the HTTPS-only configuration file
sudo tee /etc/httpd/conf.d/axis2-services.conf << 'EOF'
# Load required modules for HTTP/2 + HTTPS
LoadModule h2_module /usr/lib64/httpd/modules/mod_h2.so
LoadModule ssl_module /usr/lib64/httpd/modules/mod_ssl.so
LoadModule headers_module /usr/lib64/httpd/modules/mod_headers.so
LoadModule axis2_module /usr/local/axis2c/lib/libmod_axis2.so

# Axis2/C Configuration (standard Unix paths)
Axis2RepoPath /usr/local/axis2c
Axis2LogFile /var/log/axis2c/axis2.log
Axis2LogLevel info

# HTTP/2 Configuration (requires HTTPS)
<IfModule mod_h2.c>
    # HTTP/2 performance settings for enterprise big data
    H2WindowSize 65536
    H2MaxWorkers 256
    H2MaxSessionStreams 100
    H2StreamMaxMemSize 104857600
    H2StreamTimeout 300

    # Security: HTTP/2 only over TLS 1.2+
    H2ModernTLSOnly on
    H2Upgrade off
    H2Direct on
</IfModule>

# HTTPS Virtual Host (HTTP/2 enabled)
<VirtualHost *:443>
    ServerName localhost:443
    # HTTP/2 first, HTTP/1.1 fallback
    Protocols h2 http/1.1

    # SSL Configuration for HTTP/2
    SSLEngine on
    SSLCertificateFile /etc/pki/tls/certs/axis2-server.crt
    SSLCertificateKeyFile /etc/pki/tls/private/axis2-server.key

    # TLS 1.2+ required for HTTP/2
    SSLProtocol -all +TLSv1.2 +TLSv1.3

    # Modern cipher suites for HTTP/2
    SSLCipherSuite ECDHE+AESGCM:ECDHE+CHACHA20:DHE+AESGCM:DHE+CHACHA20:!aNULL:!MD5:!DSS
    SSLHonorCipherOrder off

    # ALPN for HTTP/2 negotiation
    SSLUseStapling on
    SSLStaplingCache shmcb:/tmp/stapling_cache(128000)

    # Security headers for HTTPS-only deployment
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
    Header always set X-Content-Type-Options nosniff
    Header always set X-Frame-Options DENY
    Header always set Content-Security-Policy "upgrade-insecure-requests"

    # Axis2/C Services (HTTPS required)
    <Location /services>
        SetHandler axis2_module
        SSLRequireSSL
        # Force HTTPS for all service requests
        Header always set Strict-Transport-Security "max-age=31536000"
    </Location>

    # Service-specific configurations
    <Location /services/BigDataH2Service>
        Header always set Cache-Control "no-cache, no-store, must-revalidate"
    </Location>

    <Location /services/LoginService>
        Header always set X-XSS-Protection "1; mode=block"
        Header always set Content-Security-Policy "default-src 'self'"
    </Location>

    <Location /services/TestwsService>
        Header always set X-XSS-Protection "1; mode=block"
        Header always set Content-Security-Policy "default-src 'self'; script-src 'none'"
    </Location>
</VirtualHost>
EOF

# Create SSL certificates for HTTP/2 testing
# HTTP/2 requires valid TLS certificates - self-signed for development only
sudo openssl req -new -x509 -days 365 -nodes \
  -out /etc/pki/tls/certs/axis2-server.crt \
  -keyout /etc/pki/tls/private/axis2-server.key \
  -config <(
    echo '[dn]'
    echo 'CN=localhost'
    echo 'C=US'
    echo 'ST=State'
    echo 'L=City'
    echo 'O=Organization'
    echo '[req]'
    echo 'distinguished_name = dn'
    echo 'req_extensions = v3_req'
    echo '[v3_req]'
    echo 'keyUsage = keyEncipherment, dataEncipherment'
    echo 'extendedKeyUsage = serverAuth'
    echo 'subjectAltName = @alt_names'
    echo '[alt_names]'
    echo 'DNS.1 = localhost'
    echo 'IP.1 = 127.0.0.1'
    echo 'IP.2 = ::1'
  )

# Set proper permissions (critical for security)
sudo chmod 600 /etc/pki/tls/private/axis2-server.key
sudo chmod 644 /etc/pki/tls/certs/axis2-server.crt

# Verify certificate for HTTP/2 compatibility
echo "🔒 Verifying SSL certificate for HTTP/2..."
openssl x509 -in /etc/pki/tls/certs/axis2-server.crt -text -noout | grep -E "(Subject Alternative Name|DNS:|IP:)"

# Test Apache configuration
sudo httpd -t

# If test passes, restart Apache for HTTPS/HTTP/2 service
sudo systemctl restart httpd
sudo systemctl enable httpd
sudo systemctl status httpd

# Verify HTTP/2 is working
echo "🚀 Testing HTTP/2 connectivity..."
curl -k -I --http2 https://localhost/

This completes Step 1. Apache httpd is now configured with HTTP/2 support and ready to serve Axis2/C services once they are built and installed in Step 2.

Important Note about JSON Processing Architecture:

Axis2/C 2.0 implements a Dual JSON Architecture that separates HTTP/1.1 and HTTP/2 JSON processing:

• HTTP/1.1 Transport: Uses json-c library with optional XML/SOAP compatibility for legacy applications
• HTTP/2 Transport: Uses optimized json-c library with zero XML/SOAP dependencies for maximum performance

This pure json-c approach for both transports provides:

• ✅ No SOAP/XML overhead: Direct JSON processing using native json-c objects
• ✅ Memory efficiency: 60-80% less memory usage compared to XML-based processing
• ✅ Performance gains: 30-40% faster JSON processing for large payloads (50MB+)
• ✅ Streaming optimization: Native support for HTTP/2 flow control and streaming

🎯 HTTP/2 Build Optimization - AXIOM Not Required:

Analysis shows that HTTP/2 JSON services do NOT require the AXIOM library (-laxis2_axiom), despite legacy header includes:

• Header Include: Services include <axiom_node.h> for compatibility but make zero function calls to axiom_* functions
• Minimal Dependencies: HTTP/2 services only need: -laxutil -laxis2_engine -ljson-c -lm
• Build Optimization: Removing -laxis2_axiom reduces runtime dependencies and proves the Dual JSON Architecture
• Performance: No XML object model overhead = faster JSON processing for HTTP/2 services

This confirms HTTP/2 services truly bypass XML/SOAP completely while maintaining source compatibility.

Critical Build Requirement: Despite HTTP/2 using pure json-c (bypassing the traditional AXIS2_JSON_ENABLED framework), the --enable-json configure flag is REQUIRED because:

• PKG-CONFIG Integration: Sets up JSON_CFLAGS and JSON_LIBS build variables
• Library Detection: Ensures json-c development headers and libraries are available
• HTTP/2 Compilation: HTTP/2 tests and utilities depend on these build variables

Both flags are essential:

./configure --enable-http2 --enable-json  # Both required for HTTP/2

Note about APR paths: The Apache Portable Runtime (APR) headers are located in different paths on different distributions:

• Ubuntu/Debian: /usr/include/apr-1.0 (includes version number with dot)
• RedHat/CentOS/Fedora: /usr/include/apr-1 (version number without dot)

If configure fails to find APR, verify the correct path on your system:

# Find APR headers on your system
find /usr/include -name "apr.h" 2>/dev/null
ls -la /usr/include/apr*

# Common alternative paths if standard ones don't work:
# /usr/include/apache2/apr-1.0  (some Ubuntu configurations)
# /usr/include/apr-1.4          (older systems)

Continue with build, start here if Apache httpd is installed with h2:

# Create services directory structure
sudo mkdir -p /usr/local/axis2c/services
sudo mkdir -p /usr/local/axis2c/modules

# Create log directory for Axis2/C
sudo mkdir -p /var/log/axis2c
sudo chown www-data:www-data /var/log/axis2c

Correct build Sequence:
# this 'find' command is optional but can fix permission errors after previous install
sudo find . -name ".libs" -type d -exec chmod -R 755 {} \; && sudo chown -R $USER:$USER . 2>/dev/null || true
autoreconf -fiv     # ✅ First: Generate build system with enhanced clean targets
./configure         # ✅ Create Makefiles that have proper clean-local targets
make distclean      # ✅ Now uses ENHANCED clean targets that remove .libs/
./configure         # ✅ Recreate Makefiles (distclean removed them)
make clean     # ✅ (aggressive - recommended)
make
sudo make install

# Run the EXACT configure command for your distro as explained below. 
# This is specifically for Ubuntu 25.10 with apache2-custom
# --enable-tests is optional, skipped here 
     ./configure --prefix=/usr/local/axis2c \
       --enable-json \
       --enable-http2 \
       --with-apache2=/usr/local/apache2/include \
       --with-apr=/usr/include/apr-1.0 \
       --enable-libxml2=no \
       PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/lib/x86_64-linux-gnu/pkgconfig \
       CFLAGS="-DAXIS2_JSON_ENABLED -DWITH_NGHTTP2 -O2" \
       CPPFLAGS="-DAXIS2_JSON_ENABLED -DWITH_NGHTTP2" \
       LDFLAGS="-L/usr/lib/x86_64-linux-gnu"

# Add Axis2/C to library path (standard Unix paths) , could be in /etc/environment or root .bashrc
export AXIS2C_HOME=/usr/local/axis2c
export LD_LIBRARY_PATH=/usr/local/axis2c/lib:$LD_LIBRARY_PATH

# Build and install HTTP/2 sample services
cd samples/user_guide/bigdata-h2-service && bash build_json_service.sh && cd ../../..
cd samples/user_guide/login-service && bash build_json_service.sh && cd ../../..
cd samples/user_guide/testws-service && bash build_json_service.sh && cd ../../..
cd samples/user_guide/camera-control-service && bash build_camera_service.sh && cd ../../..
cd samples/user_guide/financial-benchmark-service && bash build_financial_service.sh && cd ../../..

# Check which source files exist vs what's expected by Makefile.am
echo "=== BigDataH2Service ==="
[ -f "samples/user_guide/bigdata-h2-service/src/bigdata_h2_service.c" ] && [ -f "samples/user_guide/bigdata-h2-service/src/bigdata_h2_service_handler.c" ] && echo "✅ Required: bigdata_h2_service.c, bigdata_h2_service_handler.c" && echo "📁 Additional files: $(ls samples/user_guide/bigdata-h2-service/src/*.c 2>/dev/null | wc -l) total .c files" || echo "❌ Missing required .c implementation files (bigdata_h2_service.c, bigdata_h2_service_handler.c)"

echo "=== LoginService ==="
[ -f "samples/user_guide/login-service/src/login_service.c" ] && [ -f "samples/user_guide/login-service/src/login_service_handler.c" ] && echo "✅ Required: login_service.c, login_service_handler.c" && echo "📁 Additional files: $(ls samples/user_guide/login-service/src/*.c 2>/dev/null | wc -l) total .c files" || echo "❌ Missing required .c implementation files (login_service.c, login_service_handler.c)"

echo "=== TestwsService ==="
[ -f "samples/user_guide/testws-service/src/testws_service.c" ] && [ -f "samples/user_guide/testws-service/src/testws_service_handler.c" ] && echo "✅ Required: testws_service.c, testws_service_handler.c" && echo "📁 Additional files: $(ls samples/user_guide/testws-service/src/*.c 2>/dev/null | wc -l) total .c files" || echo "❌ Missing required .c implementation files (testws_service.c, testws_service_handler.c)"

echo "=== CameraControlService ==="
[ -f "samples/user_guide/camera-control-service/src/camera_control_service.c" ] && echo "✅ Required: camera_control_service.c (stub implementation)" && echo "📁 Additional files: $(ls samples/user_guide/camera-control-service/src/*.c 2>/dev/null | wc -l) total .c files" || echo "❌ Missing required .c implementation files (camera_control_service.c)"

echo "=== FinancialBenchmarkService ==="
[ -f "samples/user_guide/financial-benchmark-service/src/financial_benchmark_service.c" ] && echo "✅ Required: financial_benchmark_service.c" && echo "📁 Additional files: $(ls samples/user_guide/financial-benchmark-service/src/*.c 2>/dev/null | wc -l) total .c files" || echo "❌ Missing required .c implementation files (financial_benchmark_service.c)"

echo ""
echo "✅ ALL HTTP/2 JSON services are fully implemented and ready for build and deployment"
echo "🧪 Use curl for comprehensive HTTP/2 JSON testing including XSS protection demonstration"

Configure build (distribution-specific paths):

Ubuntu/Debian Systems:

# Configure build with JSON-C and HTTP/2 support (Ubuntu/Debian)
# IMPORTANT: --prefix=/usr/local/axis2c ensures 'sudo make install' installs to system location
# --enable-tests is optional, skipped here 
./configure \
    --prefix=/usr/local/axis2c \
    --enable-json \
    --enable-ssl \
    --enable-libcurl \
    --with-apache2=/usr/include/apache2 \
    --with-apr=/usr/include/apr-1.0 \
    PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/lib/x86_64-linux-gnu/pkgconfig \
    APACHE2_HOME=/usr \
    CFLAGS="$CFLAGS -DAXIS2_JSON_ENABLED -DWITH_NGHTTP2 -O2" \
    CPPFLAGS="$CPPFLAGS -DAXIS2_JSON_ENABLED -DWITH_NGHTTP2" \
    LDFLAGS="$LDFLAGS -L/usr/lib/x86_64-linux-gnu"

RedHat/CentOS/Fedora Systems:

# Configure build with JSON-C and HTTP/2 support (RedHat/CentOS/Fedora)
# IMPORTANT: --prefix=/usr/local/axis2c ensures 'sudo make install' installs to system location
# --enable-tests is optional, skipped here 
./configure \
    --prefix=/usr/local/axis2c \
    --enable-json \
    --enable-ssl \
    --enable-libcurl \
    --with-apache2=/usr/include/httpd \
    --with-apr=/usr/include/apr-1 \
    PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/lib64/pkgconfig \
    APACHE2_HOME=/usr \
    CFLAGS="$CFLAGS -DAXIS2_JSON_ENABLED -DWITH_NGHTTP2 -O2" \
    CPPFLAGS="$CPPFLAGS -DAXIS2_JSON_ENABLED -DWITH_NGHTTP2" \
    LDFLAGS="$LDFLAGS -L/usr/lib64"

Note about APR paths: The Apache Portable Runtime (APR) headers are located in different paths on different distributions:

• Ubuntu/Debian: /usr/include/apr-1.0 (includes version number with dot)
• RedHat/CentOS/Fedora: /usr/include/apr-1 (version number without dot)

If configure fails to find APR, verify the correct path on your system:

# Find APR headers on your system
find /usr/include -name "apr.h" 2>/dev/null
ls -la /usr/include/apr*

# Common alternative paths if standard ones don't work:
# /usr/include/apache2/apr-1.0  (some Ubuntu configurations)
# /usr/include/apr-1.4          (older systems)

Current Implementation Status:

• ✅ bigdata_h2_service_handler.c - COMPLETE - Service framework integration
• ✅ bigdata_h2_service.c - COMPLETE - Big data processing logic with HTTP/2 optimization
• ✅ login_service.c - COMPLETE - Authentication service with JWT token generation
• ✅ login_service_handler.c - COMPLETE - Service framework integration
• ✅ testws_service.c - COMPLETE - XSS protection demonstration with OWASP ESAPI-style validation
• ✅ testws_service_handler.c - COMPLETE - Service framework integration

Step 3: Test Your HTTPS/HTTP/2 Installation

Now that both Apache httpd is configured (Step 1) and Axis2/C is built and installed (Step 2), let's test the complete installation.

HTTPS/HTTP/2 connectivity test:

# Test Apache is running with HTTP/2 support
curl -k -I --http2 https://localhost/

# Verify HTTP/2 protocol is active
curl -k -I --http2 -v https://localhost/ 2>&1 | grep -E "(HTTP/2|h2|ALPN)"

# Test if services are accessible (should return service list or 404 initially)
curl -k --http2 https://localhost/services/

# Test with verbose output to confirm HTTP/2 negotiation
curl -k --http2 -v https://localhost/services/ 2>&1 | grep -E "(Using HTTP2|ALPN, server accepted to use h2)"

Verify service is up and ready for action on H2, repeat for other services as needed

curl -k --http2 -I https://localhost/services/BigDataH2Service/getServiceMetadata

HTTP/2 Protocol Verification:

# Detailed HTTP/2 verification
echo "🔍 HTTP/2 Protocol Analysis:"

# Check ALPN negotiation
echo "Testing ALPN negotiation..."
openssl s_client -connect localhost:443 -alpn h2 2>/dev/null | grep -E "(ALPN protocol: h2|Next protocol:|Protocol  : h2)"

# Check HTTP/2 stream support
curl -k --http2 -v https://localhost/ 2>&1 | grep -E "(h2|HTTP/2)"

# Test concurrent requests (HTTP/2 multiplexing)
echo "Testing HTTP/2 multiplexing..."
curl -k --http2 https://localhost/services/ & curl -k --http2 https://localhost/services/ &
wait

If all tests pass, your Apache httpd server is properly configured with HTTP/2 support and ready to serve Axis2/C services.

Client Implementation Approach:

• No custom clients - Use curl for HTTP/2 JSON testing (2025 best practice)
• Curl provides comprehensive HTTP/2, JSON, and SSL/TLS support
• Eliminates client development overhead and maintenance burden

HTTP/2 JSON Service Testing with curl

Comprehensive testing examples using curl for HTTP/2 JSON services:

⚠️ HTTP/2-Only Service Protocol Requirement

These services are configured as HTTP/2-only for optimal performance. HTTP/1.1 requests will fail with HTTP 426 “Upgrade Required”:

# ❌ This will fail with HTTP 426 - Upgrade Required
curl -k --http1.1 \
     -H "Content-Type: application/json" \
     -d '{"test":"http1_compatibility"}' \
     https://localhost/services/BigDataH2Service

# Response: "HTTP/2 Required: This service only supports HTTP/2 protocol. Please use --http2 or upgrade your client."

✅ Always use --http2 flag for testing these services. All examples below demonstrate correct HTTP/2 usage.

BigData H2 Service Testing

Test small dataset processing (standard mode):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "datasetId": "test_small_dataset",
       "datasetSize": 1048576,
       "analyticsType": "standard_analytics",
       "enableHttp2Optimization": true
     }' \
     https://localhost/services/BigDataH2Service

Test medium dataset processing (multiplexing mode):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "datasetId": "test_medium_dataset",
       "datasetSize": 26214400,
       "analyticsType": "advanced_analytics",
       "enableHttp2Optimization": true,
       "enableMemoryOptimization": true
     }' \
     https://localhost/services/BigDataH2Service

Test large dataset processing (streaming mode):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "datasetId": "test_large_dataset",
       "datasetSize": 52428800,
       "analyticsType": "enterprise_big_data",
       "enableHttp2Optimization": true
     }' \
     https://localhost/services/BigDataH2Service

Login Service Testing

Test successful authentication:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"email": "admin@example.com", "password": "admin123"}' \
     https://localhost/services/LoginService/authenticate

Expected successful response:

{
  "status": "LOGIN_SUCCESS",
  "message": "Login successful. Welcome, admin",
  "token": "eyAiYWxnIjogIkhTMjU2IiwgInR5cCI6ICJKV1QiIH0=...",
  "tokenType": "Bearer",
  "expiresIn": 3600,
  "responseTime": 1767119569
}

Test authentication failure:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"email": "invalid@example.com", "password": "wrongpassword"}' \
     https://localhost/services/LoginService/authenticate

Test input validation:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"email": "not-an-email", "password": "123"}' \
     https://localhost/services/LoginService/authenticate

TestWS Service Testing (XSS Protection Demonstration)

Test with safe input (passes validation):

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"messagein": "Hello World"}' \
     https://localhost/services/TestwsService/testXSSProtection

Expected successful response:

{
  "status": "OK",
  "messageout": "<script xmlns=\"http://www.w3.org/1999/xhtml\">alert('Hello');</script> \">",
  "securityDetails": "XSS Analysis: Input validated successfully. Output contains intentional XSS payload for demonstration purposes. WARNING: Output contains potential XSS patterns - proper HTML encoding required in production.",
  "responseTime": 1767120021
}

Test with XSS payload (fails validation):

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"messagein": "<script>alert(XSS)</script>"}' \
     https://localhost/services/TestwsService/testXSSProtection

Expected validation failure response:

{
  "status": "ERROR",
  "messageout": "",
  "securityDetails": "Input validation failed - potential security risk detected",
  "responseTime": 1767120014
}

Test with injection attempts (fails validation):

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"messagein": "javascript:alert(1)"}' \
     https://localhost/services/TestwsService/testXSSProtection

Test with HTML entities (fails validation):

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"messagein": "<img src=x onerror=alert(1)>"}' \
     https://localhost/services/TestwsService/testXSSProtection

CameraControlService Testing (Generic Camera Control with SFTP)

⚠️ Stub Implementation Notice: The CameraControlService provides stub implementations that log operations but do not perform actual camera or SFTP operations. Users must implement camera-specific integration functions. See the implementation guide at samples/user_guide/camera-control-service/IMPLEMENTATION_GUIDE.md in the source tree for detailed examples.

Test start recording (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "start_recording",
       "clip_name": "meeting_001",
       "quality": "1080p",
       "duration": 3600,
       "format": "mp4"
     }' \
     https://localhost/services/CameraControlService/startRecording

Test get camera status (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "get_status"
     }' \
     https://localhost/services/CameraControlService/getStatus

Test SFTP file transfer (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "sftp_transfer",
       "hostname": "backup.example.com",
       "username": "camera_user",
       "private_key_path": "/home/camera/.ssh/id_rsa",
       "local_file_path": "/tmp/recording_001.mp4",
       "remote_path": "/backups/camera/",
       "port": 22
     }' \
     https://localhost/services/CameraControlService/sftpTransfer

Test stop recording (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "stop_recording"
     }' \
     https://localhost/services/CameraControlService/stopRecording

Expected Response Format (Success):

{
  "success": true,
  "message": "Recording started successfully"
}

Expected Response Format (SFTP Transfer Success):

{
  "success": true,
  "message": "File transferred successfully via SFTP"
}

Expected Response Format (Get Status):

{
  "success": true,
  "state": "idle",
  "active_clip": "none",
  "recording_duration": 0,
  "last_error": "none"
}

Test configure settings (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "configure_settings",
       "resolution": "1920x1080",
       "fps": "30",
       "codec": "h264",
       "bitrate": "8000000",
       "audio_source": "mic"
     }' \
     https://localhost/services/CameraControlService/configureSettings

Test list files (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "list_files",
       "pattern": "*.mp4",
       "directory": "/storage/emulated/0/DCIM/OpenCamera"
     }' \
     https://localhost/services/CameraControlService/listFiles

Expected Response Format (List Files):

{
  "success": true,
  "file_count": 3,
  "total_size": 157286400,
  "directory": "/storage/emulated/0/DCIM/OpenCamera",
  "files": [
    {"name": "VID_20260101_120000.mp4", "size": 52428800, "modified": "2026-01-01 12:00:00"},
    {"name": "VID_20260102_140000.mp4", "size": 52428800, "modified": "2026-01-02 14:00:00"},
    {"name": "VID_20260103_160000.mp4", "size": 52428800, "modified": "2026-01-03 16:00:00"}
  ]
}

Test delete files (stub implementation):

curl -k --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "action": "delete_files",
       "pattern": "VID_20260101_*.mp4"
     }' \
     https://localhost/services/CameraControlService/deleteFiles

Supported delete patterns:

• Specific file: "VID_20260104_105049.mp4"
• Wildcard: "*.mp4", "VID_2026*"
• Date: "2026-01-04" (all files from that date)
• Today: "today" (all files from current date)
• All: "*" (delete all video files)

Implementation Requirements:

For comprehensive implementation examples including OpenCamera and libssh2 SFTP integration, see the Kanaha project:

• Kanaha Multi-Camera Deployment Guide - Camera-specific implementations for camera_device_start_recording_impl(), camera_device_stop_recording_impl(), camera_device_get_status_impl(), camera_device_configure_settings_impl(), camera_device_sftp_transfer_impl(), camera_device_list_files_impl(), and camera_device_delete_files_impl()
• Android Support Guide - Cross-compile for ARM64/ARMv7 mobile devices

Note: Kanaha is an independent project (GPLv3 licensed due to OpenCamera dependency) and is not affiliated with Apache Software Foundation. It demonstrates production deployment patterns for the CameraControlService sample in samples/user_guide/camera-control-service/.

FinancialBenchmarkService Testing (Financial Computation Benchmark)

The FinancialBenchmarkService demonstrates native C performance for compute-intensive financial calculations. It provides a direct comparison point for evaluating Axis2/C against Java/WildFly on resource-constrained hardware.

Use Case: Run financial calculations on devices where Java/WildFly cannot operate (old Android phones with 1-2GB RAM, embedded systems, edge devices).

Operations:

• portfolioVariance: O(n²) covariance matrix calculation
• monteCarlo: Monte Carlo VaR simulation
• generateTestData: Generate synthetic test portfolios
• metadata: Service information and device stats

Test service metadata:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{}' \
     https://localhost/services/FinancialBenchmarkService/metadata

Generate test portfolio data:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{"n_assets": 500}' \
     https://localhost/services/FinancialBenchmarkService/generateTestData \
     -o /tmp/portfolio_500.json

Run 500-asset portfolio variance benchmark:

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d @/tmp/portfolio_500.json \
     https://localhost/services/FinancialBenchmarkService/portfolioVariance

Run Monte Carlo simulation (10K paths):

curl -sk --http2 \
     -H "Content-Type: application/json" \
     -d '{
       "n_simulations": 10000,
       "n_periods": 252,
       "initial_value": 1000000,
       "expected_return": 0.08,
       "volatility": 0.20
     }' \
     https://localhost/services/FinancialBenchmarkService/monteCarlo

Benchmark Results (500-asset O(n²) Portfolio Variance):

Metric	Result
Assets	500
Matrix operations	250,000 (500²)
Calculation time	136 μs
Throughput	1.84 billion ops/sec
Memory usage	94 MB

Platform Comparison:

Platform	500-asset calc	Memory	Startup
Axis2/C	136 μs	~94 MB	Instant
Java/WildFly	Cannot run	4-8 GB min	30-60s

This benchmark demonstrates that Axis2/C can perform enterprise financial calculations on hardware where Java-based solutions cannot operate, making it suitable for edge computing and resource-constrained environments.

Build the service:

cd samples/user_guide/financial-benchmark-service
bash build_financial_service.sh

Architecture Comparison: Spring Boot vs Apache httpd

Component	Axis2/Java (Spring Boot)	Axis2/C (Apache httpd)
Web Server	Spring Boot Embedded Tomcat	Apache httpd with mod_h2
HTTP/2 Support	Spring Boot HTTP/2	mod_h2 (native Apache HTTP/2)
SSL/TLS	Spring Boot SSL	mod_ssl with modern cipher suites
Security	Spring Security filters	Apache httpd auth modules
JSON Processing	Spring JSON + GSON/Moshi	json-c library
Service Framework	Spring @Service annotations	Axis2/C service skeletons
Configuration	application.properties	httpd.conf + services.xml
Deployment	WAR file to app server	Service shared library
Performance	JVM heap management	Native C memory management

Service Architecture

Axis2/C services use a different architecture compared to Spring Boot:

Spring Boot (Java) Architecture:

@RestController
public class BigDataH2Service {
    @PostMapping("/processBigDataSet")
    public BigDataH2Response processBigDataSet(@RequestBody BigDataH2Request request) {
        // Processing logic
    }
}

Axis2/C Architecture:

// Service implementation using json-c
bigdata_h2_response_t* bigdata_h2_service_process_big_data_set(
    const axutil_env_t *env,
    bigdata_h2_request_t *request);

// HTTP/2 JSON service integration (pure json-c)
json_object* bigdata_h2_service_invoke_json(
    axis2_svc_skeleton_t *svc_skeleton,
    const axutil_env_t *env,
    json_object *json_request,
    axis2_msg_ctx_t *msg_ctx);

For comprehensive technical analysis and performance benchmarks that demonstrate why these C implementations achieve 30% latency reduction, 70% memory savings, and 162% faster build times compared to Java, see the Axis2/C HTTP/2 JSON Architecture document.

Resources

Documentation

• Apache Axis2/C Documentation
• Axis2/C HTTP/2 Migration State - Technical architecture and performance analysis
• Apache httpd HTTP/2 Guide
• JSON-C Library Documentation
• Apache httpd SSL/TLS Guide

Source Code and Examples

• BigDataH2Service Source Code - HTTP/2 big data processing
• LoginService Source Code - User authentication with JWT tokens
• TestwsService Source Code - XSS protection demonstration
• CameraControlService Source Code - Generic camera control with SFTP file transfer and user-implementable stub functions
• FinancialBenchmarkService Source Code - Financial computation benchmarks (O(n²) matrix operations, Monte Carlo VaR)

Security Resources

• OWASP XSS Prevention Cheat Sheet
• OWASP Authentication Cheat Sheet
• JWT Security Best Practices

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This documentation is a complete port of the Axis2/Java Spring Boot JSON user guide, adapted for Apache Axis2/C with Apache httpd deployment.