Spring Boot 与 Elastic Search 导致 java.lang.NoSuchFieldError: IGNORE_DEPRECATIONS

Question

我是弹性搜索的新手。开始使用 Elastic search 构建 Spring Boot 应用程序。

使用最新的 ES 版本 "elasticsearch-7.7.1" 并进行集成，我使用以下 maven 依赖项：

    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.7.1</version>
    </dependency>

在我的 Spring Boot 应用中添加了以下配置：

@Configuration
public class ESConfig {

  @Bean(destroyMethod = "close")
  public RestHighLevelClient client() {
    RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost")));
    return restHighLevelClient;
  }

}

将以下属性添加到 application.yaml

elasticsearch:
  host: localhost

在应用程序启动时遇到异常：

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.elasticsearch.client.RestHighLevelClient]: Factory method 'client' threw exception; nested exception is java.lang.NoSuchFieldError: IGNORE_DEPRECATIONS
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
    ... 19 common frames omitted
Caused by: java.lang.NoSuchFieldError: IGNORE_DEPRECATIONS
    at org.elasticsearch.client.RestHighLevelClient.<clinit>(RestHighLevelClient.java:1902)
    at com.sbs.communicationcontrol.search.config.ESConfig.client(ESConfig.java:14)

谁能帮忙解释一下为什么会出现这个异常？

Answer 1

经过一些研发，通过添加以下两个依赖项解决了这个问题：

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-client</artifactId>
            <version>7.7.1</version>
        </dependency>

        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.7.1</version>
        </dependency>

Answer 2

我从6.8.5 升级到org.elasticsearch.client:elasticsearch-rest-high-level-client:7.8.1 时遇到了同样的问题。问题背后的原因是将 elasticsearch-rest-high-level-client 单独更新到最新版本与它的一些依赖弹性搜索依赖项冲突，这些依赖项是由 spring-boot 作为传递依赖项引入类路径的。当我查看依赖树时，发现org.springframework.boot:spring-boot:2.3.1.RELEASE依赖带来了org.elasticsearch.client:elasticsearch-rest-client:7.6.2、org.elasticsearch:elasticsearch:7.6.2和7.6.2与7.8.1的冲突。

摘自 RestHighLevelClient 引用 IGNORE_DEPRECATIONS Java Docs 的代码 sn-p。

public class RestHighLevelClient implements Closeable {
    ....
    ....
    /**
     * Ignores deprecation warnings. This is appropriate because it is only
     * used to parse responses from Elasticsearch. Any deprecation warnings
     * emitted there just mean that you are talking to an old version of
     * Elasticsearch. There isn't anything you can do about the deprecation.
     */
    private static final DeprecationHandler DEPRECATION_HANDLER = DeprecationHandler.IGNORE_DEPRECATIONS;
   .....
   .....
}

错误本身表明我们要更新所有相关的 elasticsearch 库，虽然我找不到任何开箱即用的 elastic search BOM 来解决此版本冲突，但我已经完成了以下解决方法。

dependencies{

    implementation 'org.elasticsearch.client:elasticsearch-rest-client:7.8.1'
    implementation 'org.elasticsearch.client:elasticsearch-rest-client:7.8.1'
    implementation 'org.elasticsearch:elasticsearch:7.8.1'

}

//Since version 7.6.2 is selected by rule, substituting the version 7.8.1 as below

configurations.all {
    resolutionStrategy {
        dependencySubstitution {
            substitute module('org.elasticsearch.client:elasticsearch-rest-high-level-client') with module('org.elasticsearch.client:elasticsearch-rest-high-level-client:7.8.1')
            substitute module('org.elasticsearch.client:elasticsearch-rest-client') with module('org.elasticsearch.client:elasticsearch-rest-client:7.8.1')
            substitute module('org.elasticsearch:elasticsearch') with module('org.elasticsearch:elasticsearch:7.8.1')
            
      }
  }
}

Answer 3

你没有正确初始化你的 elasticsearch 客户端，你可以试试下面的代码：

请注意，我正在使用接受主机、端口和http 方案的版本，它对我来说很好，是standard for creating the client.

@Configuration
@Primary
public class ElasticsearchConfig {

    /**
     * Creates a Elasticsearch client from config
     *
     * @return Elasticsearch client
     */
    @Bean(destroyMethod = "close")
    public RestHighLevelClient client() {
        RestHighLevelClient client = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9500, "http")));
        return client;
    }
}

并使用下面的配置

elasticsearch.host=localhost
elasticsearch.port=9500

Answer 4

你可以为所有的Spring-boot设置版本：

ext {
    set('elasticsearch.version', '6.2.0')
}

避免在多个地方覆盖它。