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

在SpringMVC中使用Jackson实现json输出时配置如下：

<!-- 输出对象转JSON支持   -->
<bean id="stringConverter" class="org.springframework.http.converter.StringHttpMessageConverter">  
    <property name="supportedMediaTypes">  
      <list>  
        <value>text/plain;charset=UTF-8</value>  
      </list>  
    </property>  
  </bean>  
 
  <bean id="jsonConverter"  
    class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean>  
    
  <bean  
    class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
    <property name="messageConverters">  
      <list>  
        <ref bean="stringConverter"/>  
        <ref bean="jsonConverter" />  
      </list>  
    </property>  
  </bean>

Maven 坐标情况如下：

<dependency>
    <groupId>org.apache.geronimo.specs</groupId>
    <artifactId>geronimo-servlet_2.5_spec</artifactId>
    <version>1.2</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>3.2.10.RELEASE</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>3.2.10.RELEASE</version>
  </dependency>
  <dependency>
  <groupId>com.fasterxml.jackson.jaxrs</groupId>
  <artifactId>jackson-jaxrs-xml-provider</artifactId>
  <version>2.4.1</version>
  </dependency>

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：

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-xml-provider</artifactId>
    <version>2.4.1</version>
  </dependency>

改成

<dependency>
           <groupId>org.codehaus.jackson</groupId>
           <artifactId>jackson-mapper-asl</artifactId>
           <version>1.9.4</version>
     </dependency>