java.lang.ClassNotFoundException: org.codehaus.jackson.JsonProcessingException 异常解决方案

问题：

在SpringMVC中使用Jackson实现json输出时配置如下：

	
 	  
          
              
                text/plain;charset=UTF-8  
              
          
      
 
      
        
      
          
              
                  
                  
              
          
      

Maven 坐标情况如下：

        org.apache.geronimo.specs
        geronimo-servlet_2.5_spec
        1.2
    
    
        org.springframework
        spring-web
        3.2.10.RELEASE
    
    
        org.springframework
        spring-webmvc
        3.2.10.RELEASE
    
    
	com.fasterxml.jackson.jaxrs
	jackson-jaxrs-xml-provider
	2.4.1
    

出现异常如下：

严重: Servlet /pcrm threw load() exception
java.lang.ClassNotFoundException: org.codehaus.jackson.JsonProcessingException
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1718)
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
	at java.lang.Class.getDeclaredConstructors0(Native Method)
	at java.lang.Class.privateGetDeclaredConstructors(Class.java:2493)
	at java.lang.Class.getDeclaredConstructors(Class.java:1901)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:231)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineConstructorsFromBeanPostProcessors(AbstractAutowireCapableBeanFactory.java:1003)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:976)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:633)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
	at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:651)
	at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:602)
	at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:665)
	at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:521)
	at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:462)
	at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
	at javax.servlet.GenericServlet.init(GenericServlet.java:158)
	at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1279)
	at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1192)
	at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
	at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5210)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5493)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:744)

一开始以为没有导入Jackson的Jar包，但排查后发现Maven坐标有了，Jar包也导入项目了，但还是一直错。于是我在导入的Jackson包中查找 org.codehaus.jackson.JsonProcessingException类，发现导入的Jackson包中，并不是org.codehaus的Jackson包，而是com.fasterxml的Jackson包。所以确定是Maven坐标导错了。

解决方案：

将

  
		com.fasterxml.jackson.jaxrs
		jackson-jaxrs-xml-provider
		2.4.1
	

改成

    
           org.codehaus.jackson
           jackson-mapper-asl
           1.9.4