maven 依赖冲突示例<一>

问题描述

简单叙述 java.lang.NoClassDefFoundError: org/springframework/core/MethodClassKey

查找源码 发现 MethodClassKey 这个.类是在org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource.getCacheKey中被调用的,而项目中的spring 4.2.6 Release 的 AbstractFallbackTransactionAttributeSource 中 是没有getCacheKey这个方法, 说明项目存在jar包冲突问题.

下面是完整的报错情况.

java.lang.NoClassDefFoundError: org/springframework/core/MethodClassKey

	at org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource.getCacheKey(AbstractFallbackTransactionAttributeSource.java:133)
	at org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource.getTransactionAttribute(AbstractFallbackTransactionAttributeSource.java:91)
	at org.springframework.test.context.transaction.TransactionalTestExecutionListener.beforeTestMethod(TransactionalTestExecutionListener.java:173)
	at org.springframework.test.context.TestContextManager.beforeTestMethod(TestContextManager.java:265)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:254)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:193)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.ClassNotFoundException: org.springframework.core.MethodClassKey
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	... 24 more

解决思路

idea中 点击下面的方法

发现该方法为 tx-4.3.7.RELEASE

使用 maven的分支工具 Dependency Analyzer 查看 tx的相关信息如下

项目中redis的依赖 tx包版本为4.3.7.RELEASE, 所以只要排除这个依赖,再重新reimport一下maven即可

解决的pom文件更改如下, 即 排除了 spring-tx

<dependency>
			<groupId>org.springframework.data</groupId>
			<artifactId>spring-data-redis</artifactId>
			<version>${spring.data.redis}</version>
			<exclusions>
				<exclusion>
					<artifactId>spring-tx</artifactId>
					<groupId>org.springframework</groupId>
				</exclusion>
			</exclusions>
		</dependency>

总结

• 熟悉 maven的生命周期
• 熟悉maven的依赖管理
• 增加 deug 报错后的排错信息查询能力.