Test environment for local Openwhisk Java functions (#80)

diff --git a/java-local/.gitignore b/java-local/.gitignore
new file mode 100644
index 0000000..6b7597d
--- /dev/null
+++ b/java-local/.gitignore
@@ -0,0 +1,6 @@
+.settings
+.project
+.classpath
+bin/
+.gradle/
+build/
diff --git a/java-local/README.md b/java-local/README.md
new file mode 100644
index 0000000..e232eea
--- /dev/null
+++ b/java-local/README.md
@@ -0,0 +1,36 @@
+# Testing Java functions locally 
+
+## Building CLI 
+```bash
+./gradlew jar
+```
+
+## Usage
+
+```bash
+java -jar ./build/libs/java-local.jar ./path-to-function.jar parameter=value parameter2=value2 --main=myproject.Myfunction
+```
+
+Will invoke the `main` function of `myproject.Myfunction` class from `path-to-function.jar` with following `params`:
+```json
+{
+  "parameter":"value",
+  "parameter2":"value"
+}
+```
+Alternatively, you can test a single Java file by directly invoking it. In this case the Java file should not require any third party libraries.
+
+```bash
+java -jar ./build/libs/java-local.jar ./myproject/Myfunction.java parameter=value parameter2=value2 
+```
+
+This will always return a JSON formatted result that can be post-processed
+
+It is also possible to pass input on stdin, this allows the creation of more complex input
+objects that would be inconvenient to edit on the command line or passing non-string values.
+
+```bash
+echo '{"name": "value"}' | java -jar ./build/libs/java-local.jar ./path-to-function.jar --main=myproject.Myfunction
+cat input.json | java -jar ./build/libs/java-local.jar ../myproject/Myfunction.java
+```
+
diff --git a/java-local/build.gradle b/java-local/build.gradle
new file mode 100644
index 0000000..adb351c
--- /dev/null
+++ b/java-local/build.gradle
@@ -0,0 +1,25 @@
+apply plugin: 'java'
+
+repositories {
+     mavenCentral()
+}
+
+dependencies {
+    compile 'com.google.code.gson:gson:2.6.2'
+    compile 'info.picocli:picocli:2.2.0'
+
+    // Use JUnit test framework
+    testImplementation 'junit:junit:4.12'
+}
+
+jar {
+  manifest {
+    attributes(
+      'Main-Class': 'openwhisk.java.local.CLI',
+    )
+  }
+  from {
+    configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
+  }
+}
+
diff --git a/java-local/gradle/wrapper/gradle-wrapper.jar b/java-local/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..6b6ea3a
--- /dev/null
+++ b/java-local/gradle/wrapper/gradle-wrapper.jar
Binary files differ
diff --git a/java-local/gradle/wrapper/gradle-wrapper.properties b/java-local/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..0e680f3
--- /dev/null
+++ b/java-local/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.3.1-bin.zip
diff --git a/java-local/gradlew b/java-local/gradlew
new file mode 100755
index 0000000..cccdd3d
--- /dev/null
+++ b/java-local/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/java-local/gradlew.bat b/java-local/gradlew.bat
new file mode 100644
index 0000000..e95643d
--- /dev/null
+++ b/java-local/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off

+@rem ##########################################################################

+@rem

+@rem  Gradle startup script for Windows

+@rem

+@rem ##########################################################################

+

+@rem Set local scope for the variables with windows NT shell

+if "%OS%"=="Windows_NT" setlocal

+

+set DIRNAME=%~dp0

+if "%DIRNAME%" == "" set DIRNAME=.

+set APP_BASE_NAME=%~n0

+set APP_HOME=%DIRNAME%

+

+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.

+set DEFAULT_JVM_OPTS=

+

+@rem Find java.exe

+if defined JAVA_HOME goto findJavaFromJavaHome

+

+set JAVA_EXE=java.exe

+%JAVA_EXE% -version >NUL 2>&1

+if "%ERRORLEVEL%" == "0" goto init

+

+echo.

+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:findJavaFromJavaHome

+set JAVA_HOME=%JAVA_HOME:"=%

+set JAVA_EXE=%JAVA_HOME%/bin/java.exe

+

+if exist "%JAVA_EXE%" goto init

+

+echo.

+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:init

+@rem Get command-line arguments, handling Windows variants

+

+if not "%OS%" == "Windows_NT" goto win9xME_args

+

+:win9xME_args

+@rem Slurp the command line arguments.

+set CMD_LINE_ARGS=

+set _SKIP=2

+

+:win9xME_args_slurp

+if "x%~1" == "x" goto execute

+

+set CMD_LINE_ARGS=%*

+

+:execute

+@rem Setup the command line

+

+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar

+

+@rem Execute Gradle

+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%

+

+:end

+@rem End local scope for the variables with windows NT shell

+if "%ERRORLEVEL%"=="0" goto mainEnd

+

+:fail

+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of

+rem the _cmd.exe /c_ return code!

+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1

+exit /b 1

+

+:mainEnd

+if "%OS%"=="Windows_NT" endlocal

+

+:omega

diff --git a/java-local/settings.gradle b/java-local/settings.gradle
new file mode 100644
index 0000000..4ba1597
--- /dev/null
+++ b/java-local/settings.gradle
@@ -0,0 +1,18 @@
+/*
+ * This settings file was generated by the Gradle 'init' task.
+ *
+ * The settings file is used to specify which projects to include in your build.
+ * In a single project build this file can be empty or even removed.
+ *
+ * Detailed information about configuring a multi-project build in Gradle can be found
+ * in the user guide at https://docs.gradle.org/4.3.1/userguide/multi_project_builds.html
+ */
+
+/*
+// To declare projects as part of a multi-project build use the 'include' method
+include 'shared'
+include 'api'
+include 'services:webservice'
+*/
+
+rootProject.name = 'java-local'
diff --git a/java-local/src/main/java/openwhisk/java/local/CLI.java b/java-local/src/main/java/openwhisk/java/local/CLI.java
new file mode 100644
index 0000000..60dd63f
--- /dev/null
+++ b/java-local/src/main/java/openwhisk/java/local/CLI.java
@@ -0,0 +1,121 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local;
+
+import java.io.File;
+import java.io.InputStreamReader;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.stream.JsonReader;
+
+import picocli.CommandLine;
+import picocli.CommandLine.Option;
+import picocli.CommandLine.ParameterException;
+import picocli.CommandLine.Parameters;
+
+/**
+ * CLI
+ */
+public class CLI {
+
+  @Parameters(index = "0", description = "The file to execute can be a .jar or .java file")
+  private String binary;
+
+  @Parameters(index = "1..*", description = "Parameters that are passed to function", paramLabel = "param=value")
+  private Map<String, String> parameters;
+
+  @Option(names = { "--main" }, required = false, description = "name of the main class, required if using .jar")
+  private String mainClassName;
+
+  public static void main(String[] args) {
+
+    CLI cli = new CLI();
+    try {
+      CommandLine.populateCommand(cli, args);
+
+      Path path = Paths.get(cli.binary).toRealPath();
+      final boolean isJar = path.toString().endsWith(".jar");
+      final boolean isJava = path.toString().endsWith(".java");
+      if (!isJava && !isJar) {
+        System.out.printf("%s is not a jar or java file\n", cli.binary);
+        CommandLine.usage(cli, System.out);
+        return;
+      }
+
+      File f = path.toFile();
+      if (!f.canRead()) {
+        System.out.printf("%s does not exist or can not be read\n", cli.binary);
+        return;
+      }
+
+      Launcher launcher = new Launcher();
+      launcher.setBinaryPath(path);
+      launcher.setEntryClassName(cli.mainClassName);
+      launcher.setParameter(readParameters(cli));
+      JsonObject o = launcher.launch();
+      Gson gson = new Gson();
+      System.out.println(gson.toJson(o));
+      System.exit(0);
+
+    } catch (ParameterException e) {
+      System.out.println(e.getMessage());
+      CommandLine.usage(cli, System.out);
+    } catch (Exception e) {
+      e.printStackTrace();
+    }
+
+  }
+
+  private static JsonObject readParameters(CLI cli) {
+    if (cli.parameters == null || cli.parameters.isEmpty()) {
+      ExecutorService ex = Executors.newSingleThreadExecutor();
+      Future<JsonObject> result = ex.submit(() -> {
+        try(JsonReader reader = new JsonReader(new InputStreamReader(System.in))){
+          reader.setLenient(true);
+          JsonParser parser = new JsonParser();
+          JsonElement element = parser.parse(reader);
+          return element.getAsJsonObject();
+        }
+      });
+      try {
+        return result.get(1, TimeUnit.SECONDS);
+      } catch (InterruptedException | ExecutionException | TimeoutException e) {
+        result.cancel(true);
+        return new JsonObject();
+      }
+
+    } else {
+      JsonObject o = new JsonObject();
+      cli.parameters.forEach((name, value) -> {
+        o.addProperty(name, value);
+      });
+      return o;
+    }
+  }
+}
diff --git a/java-local/src/main/java/openwhisk/java/local/JarLoader.java b/java-local/src/main/java/openwhisk/java/local/JarLoader.java
new file mode 100644
index 0000000..a89c181
--- /dev/null
+++ b/java-local/src/main/java/openwhisk/java/local/JarLoader.java
@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local;
+
+import com.google.gson.JsonObject;
+
+import openwhisk.java.local.Launcher.Invoker;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
+
+/**
+ * Parts copied from https://github.com/apache/incubator-openwhisk-runtime-java/blob/master/core/javaAction/proxy/src/main/java/openwhisk/java/action/JarLoader.java
+ *
+ */
+public class JarLoader extends URLClassLoader implements Invoker{
+
+  private Class<?> mainClass;
+  private Method mainMethod;
+
+  public JarLoader(Path jarPath, String entrypoint)
+      throws MalformedURLException, ClassNotFoundException, NoSuchMethodException, SecurityException {
+    super(new URL[] { jarPath.toUri().toURL() });
+
+    final String[] splittedEntrypoint = entrypoint.split("#");
+    final String entrypointClassName = splittedEntrypoint[0];
+    final String entrypointMethodName = splittedEntrypoint.length > 1 ? splittedEntrypoint[1] : "main";
+
+    this.mainClass = loadClass(entrypointClassName);
+
+    Method m = mainClass.getMethod(entrypointMethodName, new Class[] { JsonObject.class });
+    m.setAccessible(true);
+    int modifiers = m.getModifiers();
+    if (m.getReturnType() != JsonObject.class || !Modifier.isStatic(modifiers) || !Modifier.isPublic(modifiers)) {
+      throw new NoSuchMethodException("main");
+    }
+    this.mainMethod = m;
+  }
+
+  @Override
+  public JsonObject invokeMain(JsonObject arg) throws Exception {
+    return (JsonObject) mainMethod.invoke(null, arg);
+  }
+
+}
diff --git a/java-local/src/main/java/openwhisk/java/local/JavaCompilerLoader.java b/java-local/src/main/java/openwhisk/java/local/JavaCompilerLoader.java
new file mode 100644
index 0000000..b084d67
--- /dev/null
+++ b/java-local/src/main/java/openwhisk/java/local/JavaCompilerLoader.java
@@ -0,0 +1,136 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collections;
+import java.util.List;
+
+import javax.tools.DiagnosticCollector;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaCompiler.CompilationTask;
+import javax.tools.JavaFileObject;
+import javax.tools.JavaFileObject.Kind;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.StandardLocation;
+import javax.tools.ToolProvider;
+
+import com.google.gson.JsonObject;
+
+import openwhisk.java.local.Launcher.Invoker;
+
+/**
+ * JavaCompilerLoader
+ */
+public class JavaCompilerLoader extends ClassLoader implements Invoker {
+  private MemoryFileManager fileManager;
+  private Class<?> mainClass;
+  private Method mainMethod;
+
+  public JavaCompilerLoader(ClassLoader loader, Path sourcePath) {
+    super(loader);
+    JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+    if (compiler == null) {
+      throw new RuntimeException("No java compiler. Please use a JDK not a JRE!");
+    }
+
+    try {
+      Path resolvedPath = sourcePath.toAbsolutePath();
+      DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
+      StandardJavaFileManager standardFileManager = compiler.getStandardFileManager(null, null, null);
+      String packageName = findPackageName(resolvedPath);
+      String fileName = sourcePath.getFileName().toString();
+      String className = fileName.substring(0,fileName.length()-Kind.SOURCE.extension.length());
+      if(!packageName.isEmpty())
+      {
+        className = packageName + '.' + className;
+      }
+      File sourceRoot = findSourceRoot(packageName, resolvedPath);
+      standardFileManager.setLocation(StandardLocation.SOURCE_PATH, Collections.singleton(sourceRoot));
+
+      JavaFileObject javaFile = standardFileManager.getJavaFileForInput(StandardLocation.SOURCE_PATH, className, Kind.SOURCE);
+      if(javaFile == null ){
+        System.err.printf("java file for classname does not exist file: %s\n", className);
+        return;
+      }
+      fileManager = new MemoryFileManager(loader, standardFileManager);
+      CompilationTask task = compiler.getTask(null, fileManager, diagnostics, Collections.singleton("-g"), null, Collections.singleton(javaFile));
+      boolean valid = task.call();
+      if (valid) {
+        diagnostics.getDiagnostics().forEach(System.out::println);
+      } else {
+        diagnostics.getDiagnostics().forEach(System.err::println);
+        throw new RuntimeException(String.format("Compilation for the file %s failed!\n",sourcePath.toString()));
+      }
+
+      this.mainClass = loadClass(className);
+
+      Method m = mainClass.getMethod("main", new Class[] { JsonObject.class });
+      m.setAccessible(true);
+      int modifiers = m.getModifiers();
+      if (m.getReturnType() != JsonObject.class || !Modifier.isStatic(modifiers) || !Modifier.isPublic(modifiers)) {
+        throw new NoSuchMethodException("main");
+      }
+      this.mainMethod = m;
+
+    } catch (IOException | ClassNotFoundException | NoSuchMethodException | SecurityException e) {
+      e.printStackTrace();
+	  }
+  }
+
+  @Override
+  public JsonObject invokeMain(JsonObject arg) throws Exception {
+    return (JsonObject) mainMethod.invoke(null, arg);
+  }
+
+  @Override
+  protected Class<?> findClass(String name) throws ClassNotFoundException {
+    byte[] bytecode = getClassBytes(name);
+    if (bytecode == null) {
+      throw new ClassNotFoundException(name);
+    }
+    return defineClass(name, bytecode, 0, bytecode.length);
+  }
+
+  public byte[] getClassBytes(String name) {
+    return fileManager.getCompiledClass(name);
+  }
+
+  private String findPackageName(Path sourcePath) throws IOException {
+    List<String> lines = Files.readAllLines(sourcePath.toAbsolutePath(), StandardCharsets.UTF_8);
+    for (String line : lines) {
+      if(line.startsWith("package ")){
+        int idx = line.indexOf("package ");
+        return line.substring(line.indexOf(' ', idx), line.indexOf(';', idx)).trim();
+      }
+    }
+    return "";
+  }
+
+  private File findSourceRoot(String packageName, Path sourcePath) throws IOException {
+    int packageSections = Math.toIntExact(packageName.codePoints().filter(ch -> ch =='.').count()) + 1 ;
+    packageSections++;//increment to include actual filename
+    return sourcePath.getRoot().resolve(sourcePath.subpath(0, sourcePath.getNameCount()-packageSections)).toFile();
+  }
+
+}
diff --git a/java-local/src/main/java/openwhisk/java/local/Launcher.java b/java-local/src/main/java/openwhisk/java/local/Launcher.java
new file mode 100644
index 0000000..6d78b10
--- /dev/null
+++ b/java-local/src/main/java/openwhisk/java/local/Launcher.java
@@ -0,0 +1,108 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local;
+
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.nio.file.PathMatcher;
+
+import com.google.gson.JsonObject;
+
+/**
+ * Local launcher for openwhisk functions
+ *
+ */
+public class Launcher {
+
+  private Path binaryPath;
+  private JsonObject parameter;
+  private String entryClassName;
+  private static PathMatcher JAVA_FILE_MATCHER = FileSystems.getDefault().getPathMatcher("glob:**.java");
+
+  public interface Invoker {
+    public JsonObject invokeMain(JsonObject arg) throws Exception;
+  }
+
+  /**
+   * @return the binaryPath
+   */
+  public Path getBinaryPath() {
+    return binaryPath;
+  }
+
+  /**
+   * @param binaryPath the binaryPath to set
+   */
+  public void setBinaryPath(Path binaryPath) {
+    try {
+      this.binaryPath = binaryPath.toRealPath();
+    } catch (IOException e) {
+      this.binaryPath = binaryPath;
+    }
+  }
+
+  /**
+   * @return the parameters
+   */
+  public JsonObject getParameter() {
+    return parameter;
+  }
+
+  /**
+   * @param parameters the parameters to set
+   */
+  public void setParameter(JsonObject parameter) {
+    this.parameter = parameter;
+  }
+
+  /**
+   * @return the entryClassName
+   */
+  public String getEntryClassName() {
+    return entryClassName;
+  }
+
+  /**
+   * @param entryClassName the entryClassName to set
+   */
+  public void setEntryClassName(String entryClassName) {
+    this.entryClassName = entryClassName;
+  }
+
+  public JsonObject launch() throws Exception {
+    Invoker invoker;
+    ClassLoader loader;
+    if (JAVA_FILE_MATCHER.matches(this.binaryPath)) {
+      loader = new JavaCompilerLoader(Thread.currentThread().getContextClassLoader(), this.getBinaryPath());
+      invoker = (Invoker) loader;
+    } else {
+      if (getEntryClassName() == null) {
+        throw new IllegalStateException("Main class name is required to execute .jar");
+      }
+      loader = new JarLoader(this.getBinaryPath(), getEntryClassName());
+      invoker = (Invoker) loader;
+    }
+    Thread.currentThread().setContextClassLoader(loader);
+    JsonObject args = getParameter();
+    if (args == null) {
+      args = new JsonObject(); //always pass an argument
+    }
+    return invoker.invokeMain(args);
+  }
+
+}
diff --git a/java-local/src/main/java/openwhisk/java/local/MemoryFileManager.java b/java-local/src/main/java/openwhisk/java/local/MemoryFileManager.java
new file mode 100644
index 0000000..4bcf83c
--- /dev/null
+++ b/java-local/src/main/java/openwhisk/java/local/MemoryFileManager.java
@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.tools.FileObject;
+import javax.tools.ForwardingJavaFileManager;
+import javax.tools.JavaFileManager;
+import javax.tools.JavaFileObject;
+import javax.tools.SimpleJavaFileObject;
+
+/**
+ * Keeps compiled class in memory
+ *
+ */
+public class MemoryFileManager extends ForwardingJavaFileManager<JavaFileManager> {
+  private final Map<String, ByteArrayOutputStream> compiledClasses = new HashMap<>();
+
+  public MemoryFileManager(ClassLoader classLoader, JavaFileManager fileManager) {
+    super(fileManager);
+  }
+
+  @Override
+  public JavaFileObject getJavaFileForOutput(Location location, final String className,
+                                             JavaFileObject.Kind kind, FileObject sibling) throws IOException {
+    try {
+      return new SimpleJavaFileObject(new URI(""), kind) {
+        public OutputStream openOutputStream() throws IOException {
+          ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+          compiledClasses.put(className, outputStream);
+          return outputStream;
+        }
+      };
+    } catch (URISyntaxException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  public byte[] getCompiledClass(String name) {
+    ByteArrayOutputStream bytes = compiledClasses.get(name);
+    if (bytes == null) {
+      return null;
+    }
+    return bytes.toByteArray();
+  }
+}
diff --git a/java-local/src/test/java/openwhisk/java/local/test/LauncherTest.java b/java-local/src/test/java/openwhisk/java/local/test/LauncherTest.java
new file mode 100644
index 0000000..f4f60fb
--- /dev/null
+++ b/java-local/src/test/java/openwhisk/java/local/test/LauncherTest.java
@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package openwhisk.java.local.test;
+
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+import com.google.gson.JsonObject;
+
+import openwhisk.java.local.Launcher;
+
+/**
+ * LauncherTest
+ */
+public class LauncherTest {
+
+  @Test
+  public void testLauncherParameters(){
+    Launcher launcher = new Launcher();
+    final Path binaryPath = Paths.get("/");
+
+    assertNull(launcher.getBinaryPath());
+    launcher.setBinaryPath(binaryPath);
+    assertTrue(launcher.getBinaryPath().isAbsolute());
+
+    final String className = "clazzname";
+    assertNull(launcher.getEntryClassName());
+    launcher.setEntryClassName(className);
+    assertSame(className, launcher.getEntryClassName());
+
+    final JsonObject param = new JsonObject();
+    assertNull(launcher.getParameter());
+    launcher.setParameter(param);
+    assertSame(param, launcher.getParameter());
+
+  }
+
+  @Test(expected=IllegalStateException.class)
+  public void testLaunchJarNoMain() throws Exception{
+    Launcher launcher = new Launcher();
+    Path jarPath = Paths.get("someJar.jar");
+    System.out.println(jarPath.toAbsolutePath().toString());
+    launcher.setBinaryPath(jarPath);
+    launcher.launch();
+    fail();
+  }
+
+
+  @Test
+  public void testRelativePathForJavaFile() throws Exception{
+    Launcher launcher = new Launcher();
+    Path filePath = Paths.get("./src/test/resources/aproject/App.java");
+    launcher.setBinaryPath(filePath);
+    JsonObject result = launcher.launch();
+    assertNotNull(result);
+  }
+
+  @Test
+  public void testAbsolutePathForJavaFile() throws Exception{
+    Launcher launcher = new Launcher();
+    Path filePath = Paths.get("./src/test/resources/aproject/App.java");
+    launcher.setBinaryPath(filePath.toRealPath());
+    JsonObject result = launcher.launch();
+    assertNotNull(result);
+  }
+
+
+
+  @Test
+  public void testAbsolutePathForJarLaunch() throws Exception{
+    Launcher launcher = new Launcher();
+    Path jarPath = Paths.get("./src/test/resources/serverlessJava.jar");
+    launcher.setBinaryPath(jarPath.toRealPath());
+    launcher.setEntryClassName("aproject.App");
+    JsonObject result = launcher.launch();
+    assertNotNull(result);
+  }
+
+  @Test
+  public void testRelativePathForJarLaunch() throws Exception{
+    Launcher launcher = new Launcher();
+    Path jarPath = Paths.get("./src/test/resources/serverlessJava.jar");
+    launcher.setBinaryPath(jarPath);
+    launcher.setEntryClassName("aproject.App");
+    JsonObject result = launcher.launch();
+    assertNotNull(result);
+  }
+}
+
diff --git a/java-local/src/test/resources/aproject/App.java b/java-local/src/test/resources/aproject/App.java
new file mode 100644
index 0000000..6eefc63
--- /dev/null
+++ b/java-local/src/test/resources/aproject/App.java
@@ -0,0 +1,18 @@
+package aproject;
+
+import com.google.gson.JsonObject;
+
+/*
+ * This Java source file was generated by the Gradle 'init' task.
+ */
+public class App {
+
+  public static JsonObject main(JsonObject args) {
+    String name = "stranger";
+    if (args.has("name"))
+      name = args.getAsJsonPrimitive("name").getAsString();
+    JsonObject response = new JsonObject();
+    response.addProperty("greeting", "Hello " + name + "!");
+    return response;
+  }
+}
diff --git a/java-local/src/test/resources/serverlessJava.jar b/java-local/src/test/resources/serverlessJava.jar
new file mode 100644
index 0000000..0061fac
--- /dev/null
+++ b/java-local/src/test/resources/serverlessJava.jar
Binary files differ