導致該問題的原因顧明思議就是該類沒有找到，表面上看是沒有導入相應的jar包，但往往遇到的問題是包的衝突問題，和包的依賴不全問題
1、包的版本問題
<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,同時要查看本地是否導入別的版本json-lib,有的話移除掉
2、包的依賴沒有導入全，以下的包要一起導入
<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可以輕鬆的將Java對象轉換成json對象和xml文檔，同樣也可以將json、xml轉換成Java對象，依賴如下：
<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>
https://blog.csdn.net/hangdianyizhihua/article/details/46965653
侵刪http://www.yikongyin.com/