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</groupId> <artifactId>json-lib-ext-spring</artifactId> <version>1.0.2</version></dependency>3、Jackson可以轻松的将Java对象转换成json对象和xml文档，同样也可以将json、xml转换成Java对象，依赖如下：

<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>

侵删http://www.yikongyin.com/