One Java Agent

one-java-agent

 [](https://search.maven.org/search?q=g:com.alibaba%20AND%20a:one-java-agent*)  [](http://isitmaintained.com/project/alibaba/one-java-agent "Average time to resolve an issue") [](http://isitmaintained.com/project/alibaba/one-java-agent "Percentage of issues still open")

目标

1. 提供插件化支持，统一管理众多的Java Agent
2. 插件支持install/unstall，需要插件方实现接口
3. 支持传统的java agent，即已经开发好的java agent

插件系统

插件如果希望感知生命周期，可以实现 `PluginActivator`接口：

public interface PluginActivator {
    // 让插件本身判断是否要启动
    boolean enabled(PluginContext context);

    public void init(PluginContext context) throws Exception;

    /**
     * Before calling this method, the {@link PluginState} is
     * {@link PluginState#STARTING}, after calling, the {@link PluginState} is
     * {@link PluginState#ACTIVE}
     *
     * @param context
     */
    public void start(PluginContext context) throws Exception;

    /**
     * Before calling this method, the {@link PluginState} is
     * {@link PluginState#STOPPING}, after calling, the {@link PluginState} is
     * {@link PluginState#RESOLVED}
     *
     * @param context
     */
    public void stop(PluginContext context) throws Exception;
}

传统的java agent

插件目录下面放一个`plugin.properties`，并且放上原生的agent jar文件。

例如：

type=traditional
name=demo-agent
version=1.0.0
agentJarPath=demo-agent.jar

则 one java agent会启动这个`demo-agent`。

配置注入

One Java Agent很方便可以注入配置到插件里。

1. 配置到插件的plugin.properties文件里
2. 通过-D参数配置，比如插件aaa，则可以配置为-Doneagent.plugin.aaa.key1=value1

然后可以通过`PluginContext#getProperty("ke