72、Java API初步使用_员工管理案例：基于Java实现员工信息的增删改查

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。
员工信息

• 姓名
• 年龄
• 职位
• 国家
• 入职日期
• 薪水

  1、maven依赖

  ``` org.elasticsearch.client transport 5.2.2 org.apache.logging.log4j log4j-api 2.7 org.apache.logging.log4j log4j-core 2.7

log4j2.properties

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

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

##### 2、构建client

Settings settings = Settings.builder() .put(“cluster.name”, “myClusterName”).build(); TransportClient client = new PreBuiltTransportClient(settings);

TransportClient client = new PreBuiltTransportClient(Settings.EMPTY) .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(“host1”), 9300)) .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(“host2”), 9300));

client.close();

##### 3、创建document

IndexResponse response = client.prepareIndex(“index”, “type”, “1”) .setSource(jsonBuilder() .startObject() .field(“user”, “kimchy”) .field(“postDate”, new Date()) .field(“message”, “trying out Elasticsearch”) .endObject() ) .get();

##### 4、查询document

GetResponse response = client.prepareGet(“index”, “type”, “1”).get();

##### 5、修改document

client.prepareUpdate(“index”, “type”, “1”) .setDoc(jsonBuilder()
.startObject() .field(“gender”, “male”) .endObject()) .get();

##### 6、删除document

DeleteResponse response = client.prepareDelete(“index”, “type”, “1”).get();

代码如下：

import java.net.InetAddress;

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;

/**

• 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());  
}

}

```