Elasticsearch java客户端初始化失败

Question

当我试图运行一个连接到elasticsearch的应用程序时，我得到了这个错误消息。

An attempt was made to call the method org.elasticsearch.client.RestHighLevelClient.<init>(Lorg/elasticsearch/client/RestClientBuilder;)V but it does not exist. Its class, org.elasticsearch.client.RestHighLevelClient, is available from the following locations:

jar:file:/path/application/target/application-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/elasticsearch-rest-high-level-client-5.6.3.jar!/org/elasticsearch/client/RestHighLevelClient.class

It was loaded from the following location:

jar:file:/path/application/target/application-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/elasticsearch-rest-high-level-client-5.6.3.jar!/

Action:

Correct the classpath of your application so that it contains a single, compatible version of org.elasticsearch.client.RestHighLevelClient

应用程序构建时没有错误，我的maven存储库中只存在一个版本的elasticsearch。

这是我的pom的相关部分：

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
        <relativePath />
    </parent>

    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>5.6.3</version>
    </dependency>

    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-client</artifactId>
        <version>5.6.3</version>
    </dependency>
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>5.6.3</version>
        <exclusions>
            <exclusion>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>elasticsearch-rest-client</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.elasticsearch</groupId>
                <artifactId>elasticsearch</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

这是我在运行应用程序时遇到的异常：

org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.elasticsearch.client.RestHighLevelClient]: Factory method 'restHighLevelClient' threw exception; nested exception is java.lang.NoSuchMethodError: org.elasticsearch.client.RestHighLevelClient.<init>(Lorg/elasticsearch/client/RestClientBuilder;)V

我就是这样初始化RestHighLevelClient的：

RestClientBuilder builder = RestClient
                .builder(new HttpHost(hostname, port, scheme));
builder.setMaxRetryTimeoutMillis(timeout);
RestHighLevelClient restHighLevelClient = new RestHighLevelClient(builder.build());

Answer 1

Spring将尝试自动配置elasticsearch，这将在内部使用弹性6 RestHighLevelClient(org.elasticsearch.client.RestClientBuilder构建器)来创建弹性客户端。如果您想连接到旧版本的elasticsearch，请排除elasticsearch自动配置。

@EnableAutoConfiguration(exclude={ElasticsearchAutoConfiguration.class, RestClientAutoConfiguration.class})

Answer 2

通过观察异常

java.lang.NoSuchMethodError: org.elasticsearch.client.RestHighLevelClient.<init>(Lorg/elasticsearch/client/RestClientBuilder;)

RestHighLevelClient中没有构造函数，它在<version>5.6.3</version>中将RestClientBuilder作为参数。

你试过使用<version>7.0.0-alpha1</version>版本吗？

更新：

异常An attempt was made to call the method org.elasticsearch.client.RestHighLevelClient.<init>(Lorg/elasticsearch/client/RestClientBuilder;告诉我们，代码是试图执行一个属于elasticsearch 6的方法。在您的示例中，您可能在运行时提供了多个版本的Elasticsearch库，或者您的代码可能由版本6来执行，但是在运行时提供了版本5。

Answer 3

如果您使用SpringBoot2.3.x+ Elasticsearch客户端5.6.6，下面是配置的参考，看看它是否有用。

我们最近将Spring升级为2.3.3，而ELK仍在5.6.6。这个错误与Spring自动配置ES RestClient有关，因此另一个解决方案是“手动配置它”，以后可以在其他地方使用。

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class EsConfig {

    @Value("${elasticsearch.host}")
    private String esHost;

    @Value("${elasticsearch.port}")
    private int esPort;
    
    @Value("${elasticsearch.prefix}")
    private String esPrefix;

    @Bean
    public RestClient lowLevelClient() {
        return RestClient.builder(new HttpHost(esHost, esPort, "http")).setPathPrefix(esPrefix)
                .setRequestConfigCallback(builder -> builder.setConnectTimeout(1000).setSocketTimeout(5000)).build();
    }

    @Bean
    public RestHighLevelClient restHighLevelClient() {
        return new RestHighLevelClient(this.lowLevelClient());
    }

// ------ before upgrade
//  @Bean
//  public RestHighLevelClient restHighLevelClient() {
//      RestClient rc = RestClient.builder(new HttpHost(esHost, esPort, "http")).setPathPrefix(esPrefix)
//      .setRequestConfigCallback(builder -> builder.setConnectTimeout(1000).setSocketTimeout(5000)).build();
//      return new RestHighLevelClient(rc);
//  }
}

pom：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.3.3.RELEASE</version>
    <relativePath /> 
</parent>
<!-- ..................  -->
<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>5.6.6</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>5.6.6</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>5.6.6</version>
</dependency>