谦谦君子
谦谦君子
2018-11-12  ·  1783 次阅读

Elasticsearch Java API 索引管理和数据增删改查操作

ElasticSearch 的环境安装请参考 ElasticSearch 6.0.0 安装配置 。

这节主要通过 Java API 操作 Elasticsearch。

Maven 依赖

添加 maven pom 依赖，pom.xml 代码如下：

<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.sun.elasticsearch</groupId>
    <artifactId>Elasticsearch01</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    
    <dependencies>
        <!-- Elasticsearch核心依赖包 -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>5.5.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!-- 日志依赖 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.21</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.8.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.0</version>
        </dependency>
    </dependencies>
</project>

JAVA API 连接 ElasticSearch

注意，我们通过浏览器 http://192.168.1.140:9200 访问可以正常访问 ElaticSearch，默认配置中，9200 端口是用于 Http 协议访问的，如果通过 Java API 客户端访问需要通过 9300 端口。

package com.sun.elasticsearch;
 
import java.net.InetAddress;
import java.net.UnknownHostException;
 
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
/**
 * Elasticsearch 的基本测试
 */
public class ElasticsearchTest1 {
 
    private Logger logger = LoggerFactory.getLogger(ElasticsearchTest1.class);
     
    public final static String HOST = "192.168.1.140";
    
    // http 请求的端口是 9200，客户端是 9300
    public final static int PORT = 9300;
     
    /**
     * 测试 Elasticsearch 客户端连接
     * @return void
     * @throws UnknownHostException 
     */
    @SuppressWarnings("resource")
    @Test
    public void test1() throws UnknownHostException {
        // 创建客户端
        TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
                .addTransportAddresses(new InetSocketTransportAddress(InetAddress.getByName(HOST), PORT));
         
        logger.debug("Elasticsearch connect info:" + client.toString());
 
        // 关闭客户端
        client.close();
    }
}

Elasticsearch 索引库的创建

为了简化代码，我们在修改 Junit 测试类，在方法执行之前连接 Elasticsearch，方法调用之后自动执行关闭 Elasticsearch，通过 @Before 和 @After 注解实现，具体代码如下：

private Logger logger = LoggerFactory.getLogger(ElasticsearchTest2.class);
     
    public final static String HOST = "192.168.1.140";
    
    // http 请求的端口是 9200，客户端是 9300
    public final static int PORT = 9300;
     
    private TransportClient client = null;
    
    /**
     * 获取客户端连接信息
     * @return void
     * @throws UnknownHostException 
     */
    @SuppressWarnings({ "resource", "unchecked" })
    @Before
    public void getConnect() throws UnknownHostException {
        client = new PreBuiltTransportClient(Settings.EMPTY)
                .addTransportAddresses(new InetSocketTransportAddress(InetAddress.getByName(HOST),PORT));
        logger.info("连接信息:" + client.toString());
    }
     
    /**
     * 关闭连接
     * @return void
     */
    @After
    public void closeConnect() {
        if(null != client) {
            logger.info("执行关闭连接操作...");
            client.close();
        }
    }
}

创建索引库:

/**
 * 创建索引库
 * 
 * 需求:创建一个索引库为：msg 消息队列,类型为：tweet,id 为 1,
 * 索引库的名称必须为小写
 * 
 * @return void
 * @throws IOException 
 */
@Test
public void addIndex1() throws IOException {
    IndexResponse response = client.prepareIndex("msg", "tweet", "1")
            .setSource(XContentFactory.jsonBuilder()
            .startObject().field("userName", "张三")
            .field("sendDate", new Date())
            .field("msg", "你好李四")
            .endObject())
            .get();

    logger.info("索引名称:" + response.getIndex() + "\n类型:" + response.getType()
            + "\n文档ID:" + response.getId() + "\n当前实例状态:" + response.status());
}

索引库名称必须为小写，如果为大写会报 [MQ] InvalidIndexNameException[invalid index name [MQ], must be lowercase] 错误。

invalidindexnameexception.png

此时运行代码控制台打印出如下结果，说明此时已经在 ElasticSearch 中创建成功一个为 msg 的索引库。

es-index-created.png

向索引库中添加 json 字符串

@Test
public void addIndex2() {
    String jsonStr = "{" +
            "\"userName\":\"张三\"," +
            "\"sendDate\":\"2017-11-30\"," +
            "\"msg\":\"你好李四\"" +
        "}";
    IndexResponse response = client.prepareIndex("weixin", "tweet")
            .setSource(jsonStr,XContentType.JSON)
            .get();
            
    logger.info("json索引名称:" + response.getIndex()
            + "\njson类型:" + response.getType()
            + "\njson文档ID:" + response.getId()
            + "\n当前实例json状态:" + response.status());

}

执行结果：

es-json-created.png

向索引库添加一个 Map 集合

@Test
public void addIndex3() {
    Map<String, Object> map = new HashMap<String,Object>();
    map.put("userName", "张三");
    map.put("sendDate", new Date());
    map.put("msg", "你好李四");

    IndexResponse response = client.prepareIndex("momo", "tweet")
            .setSource(map)
            .get();

    logger.info("map索引名称:" + response.getIndex()
            + "\n map类型:" + response.getType()
            + "\n map文档ID:" + response.getId()
            + "\n当前实例map状态:" + response.status());
}

执行结果：

es-map-created.png

向索引库添加 JsonObject

@Test
public void addIndex4() {
    JsonObject jsonObject = new JsonObject();
    jsonObject.addProperty("userName", "张三");
    jsonObject.addProperty("sendDate", "2017-11-23");
    jsonObject.addProperty("msg","你好李四");

    IndexResponse response = client.prepareIndex("qq", "tweet")
            .setSource(jsonObject, XContentType.JSON)
            .get();

    logger.info("jsonObject索引名称:" + response.getIndex()
            + "\n jsonObject类型:" + response.getType()
            + "\n jsonObject文档ID:" + response.getId()
            + "\n当前实例jsonObject状态:" + response.status());
}

执行结果：

es-jsonobject-created.png

从索引库查询数据

@Test
public void getData1() {
    GetResponse getResponse = client.prepareGet("msg", "tweet", "1").get();
    logger.info("索引库的数据:" + getResponse.getSourceAsString());
}

执行结果:

es-get-data.png

更新索引库数据

@Test
public void updateData() {
    JsonObject jsonObject = new JsonObject();
    jsonObject.addProperty("userName", "王五");
    jsonObject.addProperty("sendDate", "2008-08-08");
    jsonObject.addProperty("msg", "你好,张三，好久不见");

    UpdateResponse updateResponse = client.prepareUpdate("msg", "tweet", "1")
            .setDoc(jsonObject.toString(),XContentType.JSON)
            .get();

    logger.info("updateResponse索引名称:" + updateResponse.getIndex()
            + "\n updateResponse类型:" + updateResponse.getType()
            + "\n updateResponse文档ID:" + updateResponse.getId()
            + "\n当前实例updateResponse状态:" + updateResponse.status());
}

执行结果：

es-update-data.png

更新结束之后，再次调用从索引库获取数据执行结果如下:

es-update-get-data.png

删除索引库的数据

@Test
public void deleteData() {
    DeleteResponse deleteResponse = client.prepareDelete("msg", "tweet", "1").get();
    logger.info("deleteResponse索引名称:" + deleteResponse.getIndex()
            + "\n deleteResponse类型:" + deleteResponse.getType()
            + "\n deleteResponse文档ID:" + deleteResponse.getId()
            + "\n当前实例deleteResponse状态:" + deleteResponse.status());
}

执行结果:

es-delete-data.png

删除之后再次执行从索引库获取数据，结果如下：

es-delete-get-data.png

索引库的数据变为 null 了，说明删除成功。

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