json to bean（JSONObject类详解）

原博客地址：http://blog.csdn.net/harrison2010/article/details/43700991

方式一  
/** 
   * Creates a JSONDynaBean from a JSONObject. 
   */  
  public static Object toBean( JSONObject jsonObject )   
返回的数据类型明显不是我们常用的数据类型  
     
方式二  
/** 
   * Creates a bean from a JSONObject, with a specific target class.<br> 
   */  
public static Object toBean( JSONObject jsonObject, Class beanClass )   
  
方式三（常用）  
/** 
   * Creates a bean from a JSONObject, with a specific target class.<br> 
   * If beanClass is null, this method will return a graph of DynaBeans. Any 
   * attribute that is a JSONObject and matches a key in the classMap will be 
   * converted to that target class.<br> 
   * The classMap has the following conventions: 
   * <ul> 
   * <li>Every key must be an String.</li> 
   * <li>Every value must be a Class.</li> 
   * <li>A key may be a regular expression.</li> 
   * </ul> 
   */  
  public static Object toBean( JSONObject jsonObject, Class beanClass, Map classMap )   
  
  
方式四  
/** 
   * Creates a bean from a JSONObject, with the specific configuration. 
   */  
  public static Object toBean( JSONObject jsonObject, JsonConfig jsonConfig )  
方式2其实最终调用的就是方式四，看来jsonConfig对象很重要，决定了最后返回的数据类型，当然还远不至于这些。  
方式3也最终调用的是方式4  
  
  
方式五（常用）  
/** 
   * Creates a bean from a JSONObject, with the specific configuration. 
   */  
  public static Object toBean( JSONObject jsonObject, Object root, JsonConfig jsonConfig )  
直接对已有对象的处理，把json的数据写入到已有对象中。  
  
比较常用的方式三与方式五  
例子:接着bean to json的代码  
  
//二 json to object  
       
     JSONObject jsonObject = JSONObject.fromObject(returnString);  
     Object returnObject = null;  
     //办法一 class+map config的方式三  
     Map config = new  HashMap();  
     config.put("addresses", Address.class);  
     config.put("sameTest", Person.class);  
     returnObject = JSONObject.toBean(jsonObject, Person.class,config);  
     System.out.println(returnObject);  
       
     //办法二 object+JsonConfig方式五  
     p = new Person();  
     JsonConfig jc = new JsonConfig();  
     jc.setClassMap(config);  
     jc.setNewBeanInstanceStrategy(new NewBeanInstanceStrategy() {  
        @Override  
        public Object newInstance(Class target, JSONObject source)  
                throws InstantiationException, IllegalAccessException,  
                SecurityException, NoSuchMethodException, InvocationTargetException {  
              if( target != null ){  
                    if(target.getName().equals(Map.class.getName())){  
                        return new HashMap();  
                    }  
                    return NewBeanInstanceStrategy.DEFAULT.newInstance(target, source);  
                 }  
              
            return null;  
        }  
    });  
     JSONObject.toBean(jsonObject, p, jc);  
     System.out.println(p.getAddresses().get(0).getAddress());