使用java客户端操作elasticsearch

爱被打了一巴掌 2022-09-30 12:58 237阅读 0赞

# 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> 
                            <phase>package</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

![Center][]

log4j2.properties：

appender.console.type = Console
    appender.console.name = console
    appender.console.layout.type = PatternLayout
    
    rootLogger.level = info
    rootLogger.appenderRef.console.ref = console

conf.properties：

elasticsearch.clustername=xycluster
    elasticsearch.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：

![Center 1][]

6、检索elasticsearch中的数据

![Center 2][]

[Center]: /images/20220705/1b3c20ac75024affad0c882b32cb9020.png
[Center 1]: /images/20220705/bf40882c5359460f9bdb5cda42e6558b.png
[Center 2]: /images/20220705/a5b552cc280e419d98918f759e9cf26d.png