Java将Date日期类型字段转换成json字符串的方法

package com.xbmu.bean;
 
import java.io.Serializable;
import java.util.Date;
public class Student implements Serializable {
	private String username;
	private Date birthday;
	
	public Student() {
		super();
		// TODO Auto-generated constructor stub
	}
	public Student(String username, Date birthday) {
		super();
		this.username = username;
		this.birthday = birthday;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public Date getBirthday() {
		return birthday;
	}
	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}
	@Override
	public String toString() {
		return "Student [username=" + username + ", birthday=" + birthday + "]";
	}
}

package com.xbmu.test;
 
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import net.sf.json.JSONArray;
import com.xbmu.bean.Student;
public class TestDateValueToJson {
	public static void main(String[] args) {
		/**
		 * 创建三个student对象，并将对象添加到List集合中
		 * 
		 * */
		List<Student> list = new ArrayList<Student>();
		Student student = new Student("张三", new Date());
		list.add(student);
		student = new Student("李四",new Date());
		list.add(student);
		student = new Student("王五",new Date());
		list.add(student);
		
		/**将list集合众的数据转换成json格式的字符串形式*/
		JSONArray array = new JSONArray();
		array = array.fromObject(list);
		System.out.println(array.toString());

[
 {
 "birthday": {
  "date": 3,
  "day": 4,
  "hours": 9,
  "minutes": 5,
  "month": 11,
  "seconds": 1,
  "time": 1449104701018,
  "timezoneOffset": -480,
  "year": 115
 },
 "username": "张三"
 },
 {
 "birthday": {
  "date": 3,
  "day": 4,
  "hours": 9,
  "minutes": 5,
  "month": 11,
  "seconds": 1,
  "time": 1449104701018,
  "timezoneOffset": -480,
  "year": 115
 },
 "username": "李四"
 },
 {
 "birthday": {
  "date": 3,
  "day": 4,
  "hours": 9,
  "minutes": 5,
  "month": 11,
  "seconds": 1,
  "time": 1449104701018,
  "timezoneOffset": -480,
  "year": 115
 },
 "username": "王五"
 }
]

package com.xbmu.utils;
 
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;
/**
 * 自定义JsonValueProcessor
 * 比如我们要控制JSON序列化过程中的Date对象的格式化，以及数值的格式化，JsonValueProcessor是最好的选择。
 * @author bitaotao
 *
 */
public class JsonDateValueProcessor implements JsonValueProcessor {
	private String pattern = "yyyy-MM-dd";
 
	public Object processArrayValue(Object value, JsonConfig config) {
		return process(value);
	}
 
	public Object processObjectValue(String key, Object value, JsonConfig config) {
		return process(value);
	}
	private Object process(Object value){
		if(value instanceof Date){
			SimpleDateFormat sdf = new SimpleDateFormat(pattern, Locale.UK);
			return sdf.format(value);
		}
		return value == null ? "" : value.toString();
	}
 
}

package com.xbmu.test;
 
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import net.sf.json.JSONArray;
import net.sf.json.JsonConfig;
import com.xbmu.bean.Student;
import com.xbmu.utils.JsonDateValueProcessor;
 
public class TestDateValueToJson {
	public static void main(String[] args) {
		/**
		 * 创建三个student对象，并将对象添加到List集合中
		 * 
		 * */
		List<Student> list = new ArrayList<Student>();
		Student student = new Student("张三", new Date());
		list.add(student);
		student = new Student("李四",new Date());
		list.add(student);
		student = new Student("王五",new Date());
		list.add(student);
		
		/**将list集合众的数据转换成json格式的字符串形式*/
		JsonConfig config = new JsonConfig();
		JsonDateValueProcessor jsonValueProcessor = new JsonDateValueProcessor();
		config.registerJsonValueProcessor(Date.class, jsonValueProcessor);
		JSONArray array = new JSONArray();
		array = array.fromObject(list,config);
		System.out.println(array.toString());
	}
}	

[
 {
  "birthday": "2015-12-03",
  "username": "张三"
 },
 {
  "birthday": "2015-12-03",
  "username": "李四"
 },
 {
  "birthday": "2015-12-03",
  "username": "王五"
 }
]