title: Development

Overview

This document explains how to get started to develop the apisix-java-plugin-runner.

Prerequisites

Install

cd /path/to/apisix-java-plugin-runner
./mvnw install

Write Filter

Refer to the code in the sample to learn how to extend PluginFilter, define the order, rewrite requests and stop requests.

Code Location

You need to put the code in runner-plugin so that the apisix-java-plugin-runner.jar will contain the filter implementation class you wrote when you package it.

The order of filter execution

The order of execution of the filter in the runner is determined by the index of the conf array in the ext-plugin-pre-req or ext-plugin-post-req configuration.

The name of filter execution

The requests go through filters that are dynamically configured on APISIX. For example, if the following configuration is done on APISIX

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "uri":"/hello",
    "plugins":{
        "ext-plugin-pre-req":{
            "conf":[
                {
                    "name":"FooFilter",
                    "value":"bar"
                }
            ]
        }
    },
    "upstream":{
        "nodes":{
            "127.0.0.1:1980":1
        },
        "type":"roundrobin"
    }
}'

apisix-java-plugin-runner will look for implementation classes named FooFilter, and the name of each filter's implementation class is the return value of its overridden function public String name().

Rewrite Request

If you perform the following function call in the filter chain of the implementation class

  • request.setPath()
  • request.setHeader()
  • request.setArg()

this means to rewrit the current request, the upstream server will receive the relevant parameters rewritten here.

Stop Request

If you perform the following function call in the filter chain of the implementation class

  • response.setStatusCode()
  • response.setHeader()
  • response.setBody()

this means to stop the current request, the client will receive the relevant parameters generated here.

Test

Run Unit Test Suites

cd /path/to/apisix-java-plugin-runner
 ./mvnw test

Mimic practical environment

If you want to mimic the practical environment, you need to configure the route on APISIX by having the request go through the filter you want to test, for example

"plugins":{
    "ext-plugin-pre-req":{
        "conf":[
            {
                "name":"FooFilter",
                "value":"bar"
            }
        ]
    }
}

and then make a request to APISIX to trigger the route.