elasticsearch插件开发教程

package org.elasticsearch.plugin.helloworld;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

import org.elasticsearch.common.component.LifecycleComponent;
import org.elasticsearch.common.inject.Module;
import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.plugins.AbstractPlugin;
import org.elasticsearch.rest.RestModule;

public class HelloWorldPlugin extends AbstractPlugin {
 final ESLogger logger = Loggers.getLogger(getClass());

 @Override
 public String name() {
 //插件名称
 return "HelloWorld";
 }

 @Override
 public String description() {
 //插件描写叙述
 return "Hello World Plugin";
 }
 
 //处理模块，由于系统中有非常多种Module，所以须要对其类型进行推断
 @Override
 public void processModule(Module module) {
 if(module instanceof RestModule) {
  ((RestModule)module).addRestAction(HelloWorldHandler.class);
 }
 
 if(module instanceof HelloModule) {
  logger.info("############## process hello module #####################");
 }
 }
 
 @Override
 public Collection<Module> modules(Settings settings) {
 //创建自己的模块集合
 //假设没有自己定义模块，则能够返回空
 HelloModule helloModule = new HelloModule();
 ArrayList<Module> list = new ArrayList<>();
 list.add(helloModule);
 Collections.unmodifiableList(list);
 return list;
 }
 
 @SuppressWarnings("rawtypes")
 @Override
 public Collection<Class<? extends LifecycleComponent>> services() {
 //创建自己的服务类集合，服务类须要继承自LifecycleComponent。ES会自己主动创建出服务类实例，并调用其start方法
 //假设没有自己定义服务类。则能够返回空
 Collection<Class<?
 extends LifecycleComponent>> list = new ArrayList<>();
 list.add(HelloService.class);
 return list;
 }
 
}

package org.elasticsearch.plugin.helloworld;

import org.elasticsearch.common.inject.AbstractModule;
import org.elasticsearch.common.inject.Scopes;

public class HelloModule extends AbstractModule {

 @Override
 protected void configure() {
 //将InjectableService接口类型绑定到InjectableServiceImpl实现类
 //在须要注入InjectableService的地方，就会使用InjectableServiceImpl实例
 bind(InjectableService.class).to(InjectableServiceImpl.class);
 //使HelloService为单例状态
 bind(HelloService.class).in(Scopes.SINGLETON);
 }
 
}

package org.elasticsearch.plugin.helloworld;

import org.elasticsearch.client.Client;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.rest.BaseRestHandler;
import org.elasticsearch.rest.BytesRestResponse;
import org.elasticsearch.rest.RestChannel;
import org.elasticsearch.rest.RestController;
import org.elasticsearch.rest.RestRequest;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.rest.RestRequest.Method;
import org.elasticsearch.rest.RestResponse;


public class HelloWorldHandler extends BaseRestHandler {

 //注入对象
  @Inject
  protected HelloWorldHandler(Settings settings, RestController controller, Client client) {
 super(settings, controller, client);
 //将该Handler绑定到某訪问路径
 controller.registerHandler(Method.GET, "/hello/", this);
 controller.registerHandler(Method.GET, "/hello/{name}", this);
 }

 //处理绑定路径的请求訪问
 @Override
 protected void handleRequest(RestRequest request, RestChannel channel, Client client) throws Exception {
 logger.debug("HelloWorldAction.handleRequest called");
 final String name = request.hasParam("name") ? request.param("name") : "world";
 
 String content = "{\"success\":true, \"message\":\"hello " +name+ "\"}";
 
 RestResponse response = new BytesRestResponse(RestStatus.OK, BytesRestResponse.TEXT_CONTENT_TYPE, content);
 channel.sendResponse(response);
 }
}

plugin=org.elasticsearch.plugin.helloworld.HelloWorldPlugin