前面十节课我们已经把ES的基本概念和使用讲的差不多了,现在我们就用基于java来实际开发一个操作ES的小项目,带大家来一起练练手。
1、我们用IDEA创建一个maven项目
项目结构如上图所示,然后我们就引入操作ES需要用到的jar和JUNIT,pom.xml最终配置如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.kakatadage</groupId>
<artifactId>esdemo</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>6.5.1</version>
</dependency>
</dependencies>
<build>
<finalName>esdemo</finalName>
<plugins>
<plugin>
<!-- 设置javac编译器的版本和编码字符 -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>utf8</encoding><!-- 编译器编码 -->
</configuration>
</plugin>
</plugins>
</build>
</project>
项目创建完成后,我们就可以针对ES实现数据的增删改查了。
2、实现ES实现查询
新建一个测试类,如下图:
最后代码如下所示:
package com.kakatadage.esdemo.test;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;
import org.junit.Test;
import java.net.InetAddress;
import java.net.UnknownHostException;
public class EsDemo {
//从ES中查询数据
@Test
public void test1() throws UnknownHostException {
//指定ES集群
Settings setting = Settings.builder().put("cluster.name",
"my-application").build();
//创建访问ES服务器的客户端
TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(
new TransportAddress(
InetAddress.getByName("127.0.0.1"),9300));
//get方式数据查询 ,参数为Index,type和id
GetResponse response = client.prepareGet("lib4","items","5").get();
System.out.println(response.getSourceAsString());
client.close();
}
}
返回结果就是一个JSON字符串
{ "price" : null, "itemID" : "ID1005" }
3、java 插入ES一条数据
//插入数据
@Test
public void test2() throws IOException {
//指定ES集群
Settings setting = Settings.builder().put("cluster.name",
"my-application").build();
//创建访问ES服务器的客户端
TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(
new TransportAddress(
InetAddress.getByName("127.0.0.1"),9300));
XContentBuilder doc = XContentFactory.jsonBuilder()
.startObject()
.field("id","1")
.field("title","我在学习es插入操作")
.field("content","好好学习,天天向上")
.endObject();
//添加一个doc
IndexResponse response = client.prepareIndex("lib5","testadd",null)//id为null,由ES自己生成
.setSource(doc).get();
System.out.println(response.status());//打印添加是否成功
client.close();
}
返回结果:
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 1,
"hits": [
{
"_index": "lib5",
"_type": "testadd",
"_id": "dympT2cBfvwZhJjhaFQ3",
"_score": 1,
"_source": {
"id": "1",
"title": "我在学习es插入操作",
"content": "好好学习,天天向上"
}
}
]
}
}
4、java 删除ES一个文档
//删除文档
@Test
public void test3() throws IOException {
//指定ES集群
Settings setting = Settings.builder().put("cluster.name",
"my-application").build();
//创建访问ES服务器的客户端
TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(
new TransportAddress(
InetAddress.getByName("127.0.0.1"),9300));
DeleteResponse response = client.prepareDelete("lib5","testadd","dympT2cBfvwZhJjhaFQ3")
.get();
System.out.println(response.status());//打印添加是否成功
client.close();
}
5、java 修改ES一个文档
我们先新增一个,然后根据它的ID来更新
//更新文档
@Test
public void test4() throws IOException, ExecutionException, InterruptedException {
//指定ES集群
Settings setting = Settings.builder().put("cluster.name",
"my-application").build();
//创建访问ES服务器的客户端
TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(
new TransportAddress(
InetAddress.getByName("127.0.0.1"),9300));
UpdateRequest request = new UpdateRequest();
request.index("lib5")
.type("testadd")
.id("eCm1T2cBfvwZhJjhF1SM")
.doc(
XContentFactory.jsonBuilder().startObject()
.field("title","我在学习ES的修改操作")
.field("newadd","新增字段")
.endObject()
);
UpdateResponse response = client.update(request).get();
System.out.println(response.status());//打印是否成功
client.close();
}