Spring Boot连接Elasticsearch实例化Repository失败，报Connection is closed错误

问题描述 #

搭建Spring Boot应用连接Elasticsearch，配置类如下：

@Configuration
public class ElasticSearchConfig extends ElasticsearchConfiguration {
    @Override
    public ClientConfiguration clientConfiguration() {
        return ClientConfiguration.builder()
                .connectedTo("localhost:9200")
                .build();
    }
}

使用版本：

• Spring Boot：3.2.0
• Elasticsearch：8.11.1
• Java：21

实例化Elasticsearch Repository时失败，抛出核心异常为ConnectionClosedException的堆栈信息：

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.elasticsearch.repository.support.SimpleElasticsearchRepository]: Constructor threw exception
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:223) ~[spring-beans-6.1.1.jar:6.1.1]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.lambda$instantiateClass$5(RepositoryFactorySupport.java:571) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at java.base/java.util.Optional.map(Optional.java:260) ~[na:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.instantiateClass(RepositoryFactorySupport.java:571) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getTargetRepositoryViaReflection(RepositoryFactorySupport.java:536) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.elasticsearch.repository.support.ElasticsearchRepositoryFactory.getTargetRepository(ElasticsearchRepositoryFactory.java:79) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:317) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:279) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.util.Lazy.getNullable(Lazy.java:135) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.util.Lazy.get(Lazy.java:113) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:285) ~[spring-data-commons-3.2.0.jar:3.2.0]
    at org.springframework.data.elasticsearch.repository.support.ElasticsearchRepositoryFactoryBean.afterPropertiesSet(ElasticsearchRepositoryFactoryBean.java:69) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1822) ~[spring-beans-6.1.1.jar:6.1.1]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1771) ~[spring-beans-6.1.1.jar:6.1.1]
    ... 44 common frames omitted
Caused by: org.springframework.dao.DataAccessResourceFailureException: Connection is closed
    at org.springframework.data.elasticsearch.client.elc.ElasticsearchExceptionTranslator.translateExceptionIfPossible(ElasticsearchExceptionTranslator.java:110) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.client.elc.ElasticsearchExceptionTranslator.translateException(ElasticsearchExceptionTranslator.java:64) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.client.elc.ChildTemplate.execute(ChildTemplate.java:73) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.client.elc.IndicesTemplate.doExists(IndicesTemplate.java:177) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.client.elc.IndicesTemplate.exists(IndicesTemplate.java:169) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.repository.support.SimpleElasticsearchRepository.<init>(SimpleElasticsearchRepository.java:85) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486) ~[na:na]
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:210) ~[spring-beans-6.1.1.jar:6.1.1]
    ... 57 common frames omitted
Caused by: java.lang.RuntimeException: Connection is closed
    at org.springframework.data.elasticsearch.client.elc.ElasticsearchExceptionTranslator.translateException(ElasticsearchExceptionTranslator.java:63) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    ... 65 common frames omitted
Caused by: org.apache.http.ConnectionClosedException: Connection is closed
    at org.elasticsearch.client.RestClient.extractAndWrapCause(RestClient.java:920) ~[elasticsearch-rest-client-8.10.4.jar:8.10.4]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:300) ~[elasticsearch-rest-client-8.10.4.jar:8.10.4]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:288) ~[elasticsearch-rest-client-8.10.4.jar:8.10.4]
    at co.elastic.clients.transport.rest_client.RestClientHttpClient.performRequest(RestClientHttpClient.java:91) ~[elasticsearch-java-8.10.4.jar:na]
    at co.elastic.clients.transport.ElasticsearchTransportBase.performRequest(ElasticsearchTransportBase.java:137) ~[elasticsearch-java-8.10.4.jar:na]
    at co.elastic.clients.elasticsearch.indices.ElasticsearchIndicesClient.exists(ElasticsearchIndicesClient.java:655) ~[elasticsearch-java-8.10.4.jar:na]
    at org.springframework.data.elasticsearch.client.elc.IndicesTemplate.lambda$doExists$2(IndicesTemplate.java:177) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    at org.springframework.data.elasticsearch.client.elc.ChildTemplate.execute(ChildTemplate.java:71) ~[spring-data-elasticsearch-5.2.0.jar:5.2.0]
    ... 64 common frames omitted
Caused by: org.apache.http.ConnectionClosedException: Connection is closed
    at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.endOfInput(HttpAsyncRequestExecutor.java:356) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:261) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:87) ~[httpasyncclient-4.1.5.jar:4.1.5]
    at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:40) ~[httpasyncclient-4.1.5.jar:4.1.5]
    at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:114) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:591) ~[httpcore-nio-4.4.16.jar:4.4.16]
    at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]

问题分析 #

1. 版本不兼容：Spring Boot 3.2.0默认集成的Spring Data Elasticsearch 5.2.0依赖的Elasticsearch客户端版本是8.10.4，与你使用的Elasticsearch服务端8.11.1版本不匹配，导致连接协议兼容性问题。
2. 未处理安全配置：Elasticsearch 8.x默认开启HTTPS和身份验证，你的配置类未配置SSL信任和账号密码，直接连接会被服务端拒绝，引发连接关闭异常。

解决方案 #

1. 对齐客户端与服务端版本 #

在pom.xml中手动指定Elasticsearch版本，确保客户端与服务端版本一致：

<properties>
    <elasticsearch.version>8.11.1</elasticsearch.version>
</properties>

2. 配置SSL与身份验证 #

修改配置类，添加SSL信任和账号密码验证：

@Configuration
public class ElasticSearchConfig extends ElasticsearchConfiguration {
    @Value("${spring.elasticsearch.uris}")
    private String uris;
    @Value("${spring.elasticsearch.username}")
    private String username;
    @Value("${spring.elasticsearch.password}")
    private String password;

    @Override
    public ClientConfiguration clientConfiguration() {
        try {
            // 开发环境禁用SSL证书验证，生产环境建议配置信任证书
            SSLContext sslContext = SSLContextBuilder.create()
                    .loadTrustMaterial((chain, authType) -> true)
                    .build();

            return ClientConfiguration.builder()
                    .connectedTo(uris.split(","))
                    .withBasicAuth(username, password)
                    .withSslContext(sslContext)
                    .build();
        } catch (Exception e) {
            throw new RuntimeException("Failed to create SSL context", e);
        }
    }
}

在application.properties中添加配置：

spring.elasticsearch.uris=https://localhost:9200
spring.elasticsearch.username=elastic
spring.elasticsearch.password=你的Elasticsearch密码

注：Elasticsearch默认密码可在服务启动日志中找到，或使用elasticsearch-reset-password命令重置。

3. 验证Elasticsearch服务可用性 #

先通过命令行验证服务是否正常：

curl -u elastic:你的密码 https://localhost:9200 -k

返回服务信息则说明服务正常。

4. 可选：关闭自动索引创建 #

如果Repository初始化时因索引检查失败导致问题，可在实体类上添加@Document(createIndex = false)，手动创建索引后再启动应用。

内容的提问来源于stack exchange，提问作者Ammar Mohamed