类存在两次（在类路径和应用程序 jar 上）

Question

启动 Java 应用程序时出现以下错误。

我需要在启动应用程序之前将一些 hadoop 相关目录导出到类路径以使其工作（我无法跳过此步骤），并且出现以下错误。

引起原因：java.lang.LinkageError：ClassCastException：尝试强制转换jar：文件：/usr/hdp/3.0.0.0-1634/hadoop/lib/jsr311-api-1.1.1.jar！/javax/ws/rs/ext /RuntimeDelegate.class 到 jar:file:/tmp/blobStore-634df1c1-ffc8-4610-86af-8f39b33e4250/job_ac11246bea2bb31008c1a78212357514/blob_p-79f2d3193313ea987c15b4b28411db0 fc2aa436c-f858cb54126b6d546c01e5ed453bf106!/javax/ws/rs/ext/RuntimeDelegate.class 位于 javax.ws.rs .ext.RuntimeDelegate.findDelegate(RuntimeDelegate.java:146) 在 javax.ws.rs.ext.RuntimeDelegate.getInstance(RuntimeDelegate.java:120) 在 javax.ws.rs.core.UriBuilder.newInstance(UriBuilder.java:95) ）在 javax.ws.rs.core.UriBuilder.fromUri(UriBuilder.java:119) 在 org.glassfish.jersey.client.JerseyWebTarget.(JerseyWebTarget.java:71) 在 org.glassfish.jersey.client.JerseyClient。目标（JerseyClient.java：290）在org.glassfish.jersey.client.JerseyClient.target（JerseyClient.java：76）在com.hortonworks.registries.schemaregistry.client.SchemaRegistryClient.lambda $ currentSchemaRegistryTargets $ 0（SchemaRegistryClient.java：293 ）在java.util.concurrent.ConcurrentHashMap.computeIfAbsent（ConcurrentHashMap.java:1660）在com.hortonworks.registries.schemaregistry.client.SchemaRegistryClient.currentSchemaRegistryTargets（SchemaRegistryClient.java:293）在com.hortonworks.registries.schemaregistry.client。 SchemaRegistryClient.getSupportedSchemaProviders(SchemaRegistryClient.java:384) 在 com.hortonworks.registries.schemaregistry.client.SchemaRegistryClient.getDefaultDeserializer(SchemaRegistryClient.java:969) 在 SchemaService.InitDeserializer(SchemaService.java:47）在SchemaService.deserialize（SchemaService.java：38）在

经过一些研究，我发现程序尝试使用的类存在于两个不同的 JAR 文件中：

第一个是对我的 Maven 应用程序上的库的传递依赖 (javax.ws.rs.jar)

第二个是位于目录中的一个 jar，其中包含来自 hortonworks 的所有 hadoop 依赖项，我需要将其导出到类路径中以使应用程序正常工作 (jsr311-api-1.1.1.jar)

因此，我需要以某种方式告诉程序，应该使用打包在我的应用程序的 jar 中的 maven 依赖项，而不是位于类路径上的 jar。(javax.ws.rs.jar) 而不删除此 jar，因为它是一部分我的大数据集群安装，我无法使用类路径中的那些罐子。

有什么想法吗？

Answer 1

我使用这些版本将这些 jar 添加到类路径上。并构建并运行。我没有找到任何原因。<!-- https://mvnrepository.com/artifact/com.hortonworks.registries/schema-registry-client -->&nbsp; &nbsp; &nbsp; &nbsp; <dependency>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>com.hortonworks.registries</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>schema-registry-client</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <version>0.8.0</version>&nbsp; &nbsp; &nbsp; &nbsp; </dependency>&nbsp; &nbsp; &nbsp; &nbsp; <!-- https://mvnrepository.com/artifact/com.hortonworks.registries/schema-registry-serdes -->&nbsp; &nbsp; &nbsp; &nbsp; <dependency>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>com.hortonworks.registries</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>schema-registry-serdes</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <version>0.8.0</version>&nbsp; &nbsp; &nbsp; &nbsp; </dependency>&nbsp; &nbsp; &nbsp; &nbsp; <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-client -->&nbsp; &nbsp; &nbsp; &nbsp; <dependency>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>org.glassfish.jersey.core</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>jersey-client</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <version>2.29.1</version>&nbsp; &nbsp; &nbsp; &nbsp; </dependency>&nbsp; &nbsp; &nbsp; &nbsp; <!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->&nbsp; &nbsp; &nbsp; &nbsp; <dependency>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <groupId>javax.ws.rs</groupId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <artifactId>javax.ws.rs-api</artifactId>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <version>2.1</version>&nbsp; &nbsp; &nbsp; &nbsp; </dependency>

Answer 2

如果类名与解决 LinkageError 相同，则可以像这样导入。所以我们有两个同名但在不同包中的类头等舱package com.bbc.config;public class Test1 {&nbsp;}还有二等舱package com.bbc.domain;public class Test1 {}以及主要班级package com.bbc.mainclass;import com.bbc.config.Test1;public class Main {&nbsp; public static void main(String[] args) {&nbsp; // this will import from config&nbsp; &nbsp; &nbsp;&nbsp;&nbsp; Test1 test1 = new Test1(); // this will import from Test1&nbsp; // this will import from domain&nbsp; &nbsp; &nbsp; &nbsp;&nbsp; com.bbc.domain.Test1 test11 = new com.bbc.domain.Test1();&nbsp; }}