用jackson包实现json、对象、Map之间的转换

 

 

主要用于测试学习用jackson包实现json、对象、Map之间的转换。

1、准备测试用的Java类

（1）Link类

package test;

/** 
 * Description: 联系方式，被user使用
 */
public class Link
{
	private String phone; //移动电话
	private String address; //地址
	private String qq; //QQ
	
	public String getPhone()
	{
		return phone;
	}
	public void setPhone(String phone)
	{
		this.phone = phone;
	}
	public String getAddress()
	{
		return address;
	}
	public void setAddress(String address)
	{
		this.address = address;
	}
	public String getQq()
	{
		return qq;
	}
	public void setQq(String qq)
	{
		this.qq = qq;
	}
}

 

（2）User类

 

 

 

package test;

import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;

/** 
 * Description: 用户，测试模型类
 */
public class User
{
	private String id; //标识
	private String name;	//姓名
	private int age;	//年龄
	private double pay;	//工资 
	private boolean valid;	//是否有效
	private char one; //一个字符
	private Date birthday;	//生日
	
	private Link link; //联系方式，自定义
	
	private Map map; //测试用
	private List list; //测试用
	private Set set; //测试用
	public String getId()
	{
		return id;
	}
	public void setId(String id)
	{
		this.id = id;
	}
	public String getName()
	{
		return name;
	}
	public void setName(String name)
	{
		this.name = name;
	}
	public int getAge()
	{
		return age;
	}
	public void setAge(int age)
	{
		this.age = age;
	}
	public double getPay()
	{
		return pay;
	}
	public void setPay(double pay)
	{
		this.pay = pay;
	}
	public boolean isValid()
	{
		return valid;
	}
	public void setValid(boolean valid)
	{
		this.valid = valid;
	}
	public char getOne()
	{
		return one;
	}
	public void setOne(char one)
	{
		this.one = one;
	}
	public Date getBirthday()
	{
		return birthday;
	}
	public void setBirthday(Date birthday)
	{
		this.birthday = birthday;
	}
	public Link getLink()
	{
		return link;
	}
	public void setLink(Link link)
	{
		this.link = link;
	}
	public Map getMap()
	{
		return map;
	}
	public void setMap(Map map)
	{
		this.map = map;
	}
	public List getList()
	{
		return list;
	}
	public void setList(List list)
	{
		this.list = list;
	}
	public Set getSet()
	{
		return set;
	}
	public void setSet(Set set)
	{
		this.set = set;
	}
}

 

2、测试类，没用Junit，用Main()方法输出。

package test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;

/** 
 * Description: 主要用于测试学习用jackson包实现json、对象、Map之间的转换
 * 
 * Date: 2016年6月6日
 * Time: 下午3:23:23
 */
public class JsonTest
{

	public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException
	{
		User user=new User();
		user.setId("01");
		user.setName("张三");
		user.setAge(33);
		user.setPay(6666.88);
		user.setValid(true);
		user.setOne('E');
		user.setBirthday(new Date(20l*366*24*3600*1000)); //1990年
		
		Link link = new Link();
		link.setAddress("河南省济源市");
		link.setPhone("13899995555");
		link.setQq("123456");
		user.setLink(link);
		
		Map map=new HashMap();
		map.put("aa", "this is aa");
		map.put("bb", "this is bb");
		map.put("cc", "this is cc");
		user.setMap(map);
		
		List list=new ArrayList(){};
		list.add("普洱");
		list.add("大红袍");
		user.setList(list);
		
		Set set=new HashSet();
		set.add("篮球");
		set.add("足球");
		set.add("乒乓球");
		user.setSet(set);
		
		ObjectMapper mapper = new ObjectMapper(); //转换器
		
		//测试01：对象--json
		String json=mapper.writeValueAsString(user); //将对象转换成json
		System.out.println(json);
		/* 结果如下：
		{"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":1465185448998,
		"link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"},
		"map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"},
		"list":["普洱","大红袍"],
		"set":["乒乓球","足球","篮球"]}
		
		注意点：（1） 日期--长整型 （2）List、Set均转成数组
		 */
		
		//测试02：json--map
		Map m = mapper.readValue(json, Map.class); //json转换成map
		
		System.out.println("pay："+m.get("pay").getClass().getName()); //java.lang.Double
		System.out.println("valid："+m.get("valid").getClass().getName()); //java.lang.Boolean
		System.out.println("birthday："+m.get("birthday").getClass().getName()); //java.lang.Long
		System.out.println("link："+m.get("link").getClass().getName()); //java.util.LinkedHashMap
		System.out.println("map："+m.get("map").getClass().getName()); //java.util.LinkedHashMap
		System.out.println("list："+m.get("list").getClass().getName()); //java.util.ArrayList
		System.out.println("set："+m.get("set").getClass().getName()); //java.util.ArrayList
		/*  结果如下：
		  	pay：java.lang.Double
			valid：java.lang.Boolean
			birthday：java.lang.Long
			link：java.util.LinkedHashMap
			map：java.util.LinkedHashMap
			list：java.util.ArrayList
			set：java.util.ArrayList
			
			注意点：（1） 日期--长整型  （2）map、子对象均转换成了LinkedHashMap （3）List、Set均转成ArrayList
		 */
		
		//测试03：map--json
		json=mapper.writeValueAsString(m); //map转json
		System.out.println(json); //与之前格式完全相同，说明经过map转换后，信息没有丢失
		
		//测试04：json--对象
		User u=mapper.readValue(json, User.class); //json转java对象。经测，转成对象后，一切恢复正常
		System.out.println("pay："+u.getPay());
		System.out.println("valid："+u.isValid());
		System.out.println("birthday："+u.getBirthday());
		System.out.println("link："+u.getLink());
		System.out.println("map："+u.getMap());
		System.out.println("list："+u.getList());
		System.out.println("set："+u.getSet());
		
		//测试05：其他转换
		byte[] data=mapper.writeValueAsBytes(u); //对象转成二进制数组
		
		
	}

}

 

3、输出结果

{"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":632448000000,"link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"},"map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"},"list":["普洱","大红袍"],"set":["乒乓球","足球","篮球"]}
pay：java.lang.Double
valid：java.lang.Boolean
birthday：java.lang.Long
link：java.util.LinkedHashMap
map：java.util.LinkedHashMap
list：java.util.ArrayList
set：java.util.ArrayList
{"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":632448000000,"link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"},"map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"},"list":["普洱","大红袍"],"set":["乒乓球","足球","篮球"]}
pay：6666.88
valid：true
birthday：Tue Jan 16 08:00:00 CST 1990
link：test.Link@350385f1
map：{aa=this is aa, bb=this is bb, cc=this is cc}
list：[普洱, 大红袍]
set：[足球, 乒乓球, 篮球]