通过codehaus来实现json写入文件和读取文件成json对象

pom.xml需要增加如下依赖：

<dependency> 
<groupId>org.codehaus.jackson</groupId> 
<artifactId>jackson-core-lgpl</artifactId> 
<version>1.9.1</version> 
</dependency> 
<dependency> 
<groupId>org.codehaus.jackson</groupId> 
<artifactId>jackson-mapper-lgpl</artifactId> 
<version>1.9.1</version> 
</dependency><dependency> 
<groupId>or