public class GsonUtil {
  public static Gson gson;
  /**Json转JavaBean**/
  public static final int JSON_JAVABEAN=0x10001;
  /**Json转List<T>**/
  public static final int JSON_LIST=0x10002;
  /**Json转Map<T>**/
  public static final int JSON_MAP=0x10004;

  /**
   * 将对象转换成Json格式的字符串
   * @param object 要转换成Json的对象
   * @return String:Json格式的字符串
   */
  public static String convertObject2Json(Object object) {   
    gson=new Gson();      
    return gson.toJson(object);
  } 
  /**
   * 将Json转换成Java对象
   * @param inputStream 要转换成Java对象的inputStream
   * @param javaBean List获取Map中所包含的javaBean
   * @param convertFlag 转换类型标识
   * @return Object:Java对象
   */
  public static Object convertJson2Object(InputStream inputStream,Class<?>javaBean ,int convertFlag) {    
    gson=new Gson();  
    Object object=null;
//   String json=inputStream2String(inputStream);
    BufferedReader reader=intputStream2BufferedReader(inputStream);  
    Type type=getType(javaBean,convertFlag);  
    object=gson.fromJson(reader,type);     
    return object;
  }
  /**
   * 获取要转换成的对象类型
   * @param javaBean
   * @param convertFlag
   * @return
   */
  private static Type getType(Class<?> javaBean,int convertFlag) {   
    Type type=null;
    switch (convertFlag) {
    case JSON_LIST:
      if (javaBean.equals(News.class)) {//Json转List泛型
        type=new TypeToken<List<News>>(){}.getType();
      }
      break;
    case JSON_MAP:
      if (javaBean.equals(News.class)) {//Json转Map泛型
        type=new TypeToken<Map<String,News>>(){}.getType();
      }
      break;    
    case JSON_JAVABEAN://Json转JavaBean
      type=javaBean;
      break;    
    }   
    return type; 
  }
  /**
   * 将InputStream封装成BufferedReader
   * @param inputStream
   * @return
   */
  private static BufferedReader intputStream2BufferedReader(InputStream inputStream) {   
    return new BufferedReader(new InputStreamReader(inputStream));  
  }
}