导致该问题的原因顾明思议就是该类没有找到，表面上看是没有导入相应的jar包，但往往遇到的问题是包的冲突问题，和包的依赖不全问题

1、包的版本问题

<dependency>  <groupId>net.sf.json-lib</groupId>  <artifactId>json-lib</artifactId>  <version>2.4</version>  <classifier>jdk15</classifier> </dependency>

需要制定jdk的版本，jdk15表示jdk1.5,同时要查看本地是否导入别的版本json-lib,有的话移除掉

2、包的依赖没有导入全，以下的包要一起导入

<dependency>
    <groupId>commons-lang</groupId>
    <artifactId>commons-lang</artifactId>
    <version>2.6</version>
</dependency>
<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>
<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.8.3</version>
</dependency>
<dependency>
    <groupId>commons-collections</groupId>
    <artifactId>commons-collections</artifactId>
    <version>3.2</version>
</dependency>
<dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging</artifactId>
    <version>1.1.1</version>
</dependency>
<dependency>
    <groupId>net.sf.ezmorph</groupId>
    <artifactId>ezmorph</artifactId>
    <version>1.0.6</version>
</dependency>
<dependency>    groupId>net.sf.json-lib</artifactId>json-lib-ext-springversion>1.0.2>>

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>1.9.13</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>1.9.13</version>
</dependency>