使用java客户端操作elasticsearch

本文主要参考：

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html

本文的主要目的不是追求如何用java语言进行elasticsearch的操作，而是如何搭建一个环境，这个环境能够进行访问elasticsearch。

好，下面上货。

1、首先新建一个简单maven项目。

mvn archetype:generate -DarchetypeCatalog=internal

2、然后修改pom文件，添加依赖。

<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>

添加plugins查看，方便打jar包。

<plugins>            <plugin>                <groupId>org.apache.maven.plugins</groupId>                <artifactId>maven-compiler-plugin</artifactId>                <configuration>                    <source>1.8</source>                    <target>1.8</target>                    <encoding>utf-8</encoding>                </configuration>            </plugin>            <plugin>                <artifactId>maven-assembly-plugin</artifactId>                <version>3.0.0</version>                <configuration>                    <archive>                        <manifest>                            <mainClass>com.xueyouc.xueyou.App</mainClass>                        </manifest>                    </archive>                    <descriptorRefs>                        <descriptorRef>jar-with-dependencies</descriptorRef>                    </descriptorRefs>                </configuration>                <executions>                    <execution>                        <id>make-assembly</id> <!-- this is used for inheritance merges -->                        <phase>package</phase> <!-- bind to the packaging phase -->                        <goals>                            <goal>single</goal>                        </goals>                    </execution>                </executions>            </plugin>        </plugins>

3、添加log4j2的配置文件和本地配置文件

log4j2.properties：

appender.console.type = Consoleappender.console.name = consoleappender.console.layout.type = PatternLayoutrootLogger.level = inforootLogger.appenderRef.console.ref = console

conf.properties：

elasticsearch.clustername=xyclusterelasticsearch.addr1=127.0.0.1

4、编写程序实现对elasticsearch的访问：

App.java

package com.xueyouc.xueyou;import org.elasticsearch.action.index.IndexResponse;import org.elasticsearch.client.transport.TransportClient;import org.elasticsearch.common.settings.Settings;import org.elasticsearch.common.transport.InetSocketTransportAddress;import org.elasticsearch.common.xcontent.XContentBuilder;import org.elasticsearch.transport.client.PreBuiltTransportClient;import java.io.IOException;import java.net.InetAddress;import java.net.UnknownHostException;import java.util.Date;import java.util.ResourceBundle;import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;/** * Hello world! */public class App {    public static void main(String[] args) {        /**         * 读取配置文件         */        ResourceBundle rb = ResourceBundle.getBundle("conf");        String clustername = rb.getString("elasticsearch.clustername");        String addr1 = rb.getString("elasticsearch.addr1");        String[] temparray = addr1.split("\\.");        byte[] localAddr = new byte[temparray.length];        for (int i = 0; i < temparray.length; i++) {            localAddr[i] = Byte.parseByte(temparray[i]);        }        TransportClient client = null;        try {            Settings settings = Settings.builder().put("cluster.name", clustername).build();            client = new PreBuiltTransportClient(settings)                    .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByAddress(localAddr), 9300));            //插入你的处理逻辑            try {                XContentBuilder builder = jsonBuilder().startObject().field("user", "user002").field("postDate", new Date()).field("message", "trying out elasticsearch").endObject();                IndexResponse response = client.prepareIndex("testindex","testtype","2").setSource(builder).execute().actionGet();                System.out.println("============================");                System.out.println(response.getIndex());                System.out.println(response.getType());                System.out.println(response.getId());                System.out.println("============================");            } catch (IOException e) {                e.printStackTrace();            } finally {            }        } catch (UnknownHostException e) {            e.printStackTrace();        } finally {            client.close();        }    }}

上面的代码需要优化：

localAddr[i] = (byte) Integer.parseInt(temparray[i]);

5、运行结果：

6、检索elasticsearch中的数据