list转json的一些问题

利用JSONArray转换list

定义的model：

 package com.yds.model;

 import java.util.Date;

 public class DeviceHistory {

     private int id;
     private Date acq_time; 

     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getDevice_id() {
         return device_id;
     }

     public Date getAcq_time() {
         return acq_time;
     }
     public void setAcq_time(Date acq_time) {
         this.acq_time = acq_time;
     }

 }

测试类：

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import net.sf.json.JSONArray;
import com.yds.model.DeviceHistory;
public class Test {
    public static void main(String[] args) {
        List<DeviceHistory> list = new ArrayList<DeviceHistory>();
        DeviceHistory dh = new DeviceHistory();
        dh.setAcq_time(new Date());
        list.add(dh);
        JSONArray json =JSONArray.fromObject(list);
        System.out.println(json.toString());
    }

}

打印结果为：

[{"acq_time":{"date":18,"day":2,"hours":21,"minutes":7,"month":7,"seconds":27,"time":1439903247640,"timezoneOffset":-480,"year":115},"id":0}]

开始时我用的JSONArray在action中进行list转换 发现到JSONArray json =JSONArray.fromObject(list);就执行不下去了,经过一番调发现是时间转换时出了问题，就换了jackson进行转换

测试类：

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;

 import org.codehaus.jackson.JsonGenerationException;
 import org.codehaus.jackson.map.JsonMappingException;
 import org.codehaus.jackson.map.ObjectMapper;
 import com.yds.model.DeviceHistory;

 public class Test {
     public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException {
         List<DeviceHistory> list = new ArrayList<DeviceHistory>();
         DeviceHistory dh = new DeviceHistory();
         dh.setAcq_time(new Date());
         list.add(dh);
         ObjectMapper objectMapper = new ObjectMapper();
         String json = objectMapper.writeValueAsString(list);
         System.out.println(json);
     }

 }

打印结果为：

[{"id":0,"acq_time":1439904893237}] 这样action也能执行下去了