list转json的一些问题

利用JSONArray转换list

定义的model：

 1 package com.yds.model; 2  3 import java.util.Date; 4  5  6  7 public class DeviceHistory { 8  9     PRivate int id; 10     private Date acq_time; 11     12     13     14     public int getId() {15         return id;16     }17     public void setId(int id) {18         this.id = id;19     }20     public String getDevice_id() {21         return device_id;22     }23     24     public Date getAcq_time() {25         return acq_time;26     }27     public void setAcq_time(Date acq_time) {28         this.acq_time = acq_time;29     }30 31 }

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：

 1 import java.io.IOException; 2 import java.util.ArrayList; 3 import java.util.Date; 4 import java.util.List; 5  6 import org.codehaus.jackson.JsonGenerationException; 7 import org.codehaus.jackson.map.JsonMappingException; 8 import org.codehaus.jackson.map.ObjectMapper; 9 import com.yds.model.DeviceHistory;10 11 public class Test {12     public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException {13         List<DeviceHistory> list = new ArrayList<DeviceHistory>();14         DeviceHistory dh = new DeviceHistory();15         dh.setAcq_time(new Date());16         list.add(dh);17         ObjectMapper objectMapper = new ObjectMapper();18         String json = objectMapper.writeValueAsString(list);19         System.out.println(json);20     }21 22 }

打印结果为：

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