JSON转换为JAVA对象及日期格式转换处理

1.JSON日期格式转换

默认JSON对DATE类型会转换成一个多属性对象, 而不是单独的一个字符串, 在某些应用处理上不是很方便,  可以利用JsonValueProcessor来实现日期的转换.

 默认格式:

"lastUpdate": {
                "date": 29,
                "day": 3,
                "hours": 14,
                "minutes": 46,
                "month": 1,
                "seconds": 41,
                "time": 1330498001000,
                "timezoneOffset": -480,
                "year": 112
            },

转换后格式:

"lastUpdate": "2012-02-29 14:46:41"

自定义一个日期处理器:

DateJsonValueProcessor是实现了一个JsonValueProcessor接口(两种方式)

 import java.text.SimpleDateFormat;
 import java.util.Date;

 import net.sf.json.JsonConfig;
 import net.sf.json.processors.JsonValueProcessor;

 /**
  * JSON日期格式转换
  *
 */
 public class DateJsonValueProcessor implements JsonValueProcessor
 {
     private String format = "yyyy-MM-dd HH:mm:ss";

     public DateJsonValueProcessor()
     {

     }

     public DateJsonValueProcessor(String format)
     {

         this.format = format;
     }

     public Object processArrayValue(Object value, JsonConfig jsonConfig)
     {

         String[] obj = {};
         if (value instanceof Date[])
         {
             SimpleDateFormat sf = new SimpleDateFormat(format);
             Date[] dates = (Date[]) value;
             obj = new String[dates.length];
             for (int i = 0; i < dates.length; i++)
             {
                 obj[i] = sf.format(dates[i]);
             }
         }
         return obj;
     }

     public Object processObjectValue(String key, Object value, JsonConfig jsonConfig)
     {

         if (value instanceof Date)
         {
             String str = new SimpleDateFormat(format).format((Date) value);
             return str;
         }
         return value;
     }

     public String getFormat()
     {

         return format;
     }

     public void setFormat(String format)
     {

         this.format = format;
     }

 }

或:

 package org.ymm.util;

 import java.text.SimpleDateFormat;
 import net.sf.json.JsonConfig;
 import net.sf.json.processors.JsonValueProcessor;

 public class DateJsonValueProcessor implements JsonValueProcessor
 {

     private String format;
     public DateJsonValueProcessor(String format){
         this.format = format;
     }

     public Object processArrayValue(Object value, JsonConfig jsonConfig)
     {
         return null;
     }

     public Object processObjectValue(String key, Object value, JsonConfig jsonConfig)
     {
         if(value == null)
         {
             return "";
         }
         if(value instanceof java.sql.Timestamp)
         {
             String str = new SimpleDateFormat(format).format((java.sql.Timestamp)value);
             return str;
         }
         if (value instanceof java.util.Date)
         {
             String str = new SimpleDateFormat(format).format((java.util.Date) value);
             return str;
         }

         return value.toString();
     }
 }

转换调用代码:

	public String queryEmpAll() throws IOException{
		System.out.println("queryEmpAll!!!!!!!!!!!!!!!!!!!!!!!");	
//		PrintWriter out=ServletActionContext.getResponse().getWriter();
		
		JsonConfig jsonConfig = new JsonConfig();  
		jsonConfig.registerJsonValueProcessor(java.util.Date.class, new JsonDateValueProcessor()); 
		jsonConfig.registerJsonValueProcessor(java.sql.Timestamp.class, new JsonDateValueProcessor()); 
		
		Map map=new HashMap();
		map.put("total", 3);
		map.put("data", ies.getAll());
		
		JSONObject jn=JSONObject.fromObject(map,jsonConfig);
		
		System.out.println(jn.toString());
//		out.print(jn.toString());
		return null;
	}