Java:JSON和Map相互转换

Java：JSON与Map相互转换

需要jar包：jackson-core-2.6.0.jar，jackson-databind-2.6.0.jar，jackson-annotations-2.6.0.jar

1. JSON String to Map

package com.inspur.trc.util;

import java.util.HashMap;
import java.util.Map;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Json2Map {
	public static void main(String[] args) {
		String json = "{\"name\":\"zitong\", \"age\":\"26\"}";
		Map map = new HashMap();
		ObjectMapper mapper = new ObjectMapper();
		
		try{
			map = mapper.readValue(json, new TypeReference>(){});
			System.out.println(map);
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}

运行结果：

{age=26, name=zitong}

2. Map to JSON String

package com.inspur.trc.util;

import java.util.HashMap;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;

public class Map2Json {
	public static void main(String[] args){
		try{
			ObjectMapper mapper = new ObjectMapper();
			String json = "";
			
			Map map = new HashMap();
			map.put("name", "zitong");
			map.put("age", "26");
			
			json = mapper.writeValueAsString(map);
			
			System.out.println(json);
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}

运行结果：

{"age":"26","name":"zitong"}

3. Map to JSON File

package com.inspur.trc.util;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;

public class Map2JsonFile {
	public static void main(String[] args) {
		ObjectMapper mapper = new ObjectMapper();
		Map map = new HashMap();
		map.put("name", "zitong");
		map.put("age", 29);

		List