68、Java API初步使用_员工管理案例：基于Java实现员

1、es这门技术有点特殊，跟比如其他的像纯java的课程，比如分布式课程，或者大数据类的课程，比如hadoop，spark，storm等。不太一样
2、es非常重要的一个api，是它的restful api，你自己思考一下，掌握这个es的restful api，可以让你执行一些核心的运维管理的操作，比如说创建索引，维护索引，执行各种refresh、flush、optimize操作，查看集群的健康状况，比如还有其他的一些操作，就不在这里枚举了。或者说探查一些数据，可能用java api并不方便。
3、es的学习，首先，你必须学好restful api，然后才是你自己的熟悉语言的api，java api。

1、添加pom依赖

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>5.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.7</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.7</version>
        </dependency>

2、log4j配置文件

appender.console.type = Console
appender.console.name = console
appender.console.layout.type = PatternLayout

rootLogger.level = info
rootLogger.appenderRef.console.ref = console

3、编写代码

package com.roncoo.es.score.first;

import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.net.InetAddress;

/**
 * 员工增删改查的应用程序
 * @author Administrator
 *
 */
public class EmployeeCRUDApp {

    @SuppressWarnings({ "unchecked", "resource" })
    public static void main(String[] args) throws Exception {
        // 先构建client
        Settings settings = Settings.builder()
                .put("cluster.name", "elasticsearch")
                .build();
        
        TransportClient client = new PreBuiltTransportClient(settings)
                .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
        
//      createEmployee(client);
//      getEmployee(client);
//      updateEmployee(client);
//      deleteEmployee(client);
        
        client.close();
    }
    
    /**
     * 创建员工信息（创建一个document）
     * @param client
     */
    private static void createEmployee(TransportClient client) throws Exception {
        IndexResponse response = client.prepareIndex("company", "employee", "1")
                .setSource(XContentFactory.jsonBuilder()
                        .startObject()
                            .field("name", "jack")
                            .field("age", 27)
                            .field("position", "technique")
                            .field("country", "china")
                            .field("join_date", "2017-01-01")
                            .field("salary", 10000)
                        .endObject())
                .get();
        System.out.println(response.getResult()); 
    }
    
    /**
     * 获取员工信息
     * @param client
     * @throws Exception
     */
    private static void getEmployee(TransportClient client) throws Exception {
        GetResponse response = client.prepareGet("company", "employee", "1").get();
        System.out.println(response.getSourceAsString()); 
    }
    
    /**
     * 修改员工信息
     * @param client
     * @throws Exception
     */
    private static void updateEmployee(TransportClient client) throws Exception {
        UpdateResponse response = client.prepareUpdate("company", "employee", "1") 
                .setDoc(XContentFactory.jsonBuilder()
                            .startObject()
                                .field("position", "technique manager")
                            .endObject())
                .get();
        System.out.println(response.getResult());  
    }
    
    /**
     * 删除 员工信息
     * @param client
     * @throws Exception
     */
    private static void deleteEmployee(TransportClient client) throws Exception {
        DeleteResponse response = client.prepareDelete("company", "employee", "1").get();
        System.out.println(response.getResult());  
    }
    
}