Java基础之JsonUtils类

package pde.ams.util;

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

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

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import pde.ams.model.Students;
import pde.ams.model.User;

/**
 * @author 作者 macx:
 * @version 创建时间：2018年4月28日 下午9:51:27 类说明
 */
public class JsonUtils {

	public static void main(String[] args) {
		// MapToJson();
		// MapToJson2();
		// ObjectToJson();
		// ArrayToJson();
		// ListToJson();
	}

	private static void MapToJson2() {
		try {
			ObjectMapper mapper = new ObjectMapper();
			String json = "";
			Map<String, String> map = new HashMap<String, String>();
			map.put("name", "zitong");
			map.put("age", "26");

			json = mapper.writeValueAsString(map);

			System.out.println(json);
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	public static void ListToJson() {
		List<User> list = new ArrayList<User>();
		User user = new User("1001", "张三");
		list.add(user);
		list.add(user);
		list.add(user);
		JSONArray jsonArray = JSONArray.fromObject(list);
		System.out.println(jsonArray);
	}

	public static void ArrayToJson() {
		String[] arr = { "asd", "dfgd", "asd", "234" };
		JSONArray jsonarray = JSONArray.fromObject(arr);
		System.out.println(jsonarray);
	}

	public static void MapToJson() {
		Map<String, Object> map = new HashMap<String, Object>();
		Map<String, Object> map1 = new HashMap<String, Object>();
		map1.put("userSon", "我是儿子");
		map.put("userId", 1001);
		map.put("userName", "张三");
		map.put("userSex", "男");
		// map.put("userContent", map1);
		JSONObject jsonObject = JSONObject.fromObject(map);
		System.out.println(jsonObject);

		ObjectMapper mapper = new ObjectMapper();
		// 当这里转换为Map的Map时，会报错；待解决；
		try {
			map = mapper.readValue(jsonObject.toString(),
					new TypeReference<HashMap<String, String>>() {
					});
			System.out.println("转换为map的值" + map);
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	public static void ObjectToJson() {
		// User user = new User("1001","张三");
		User user = new User();
		user.setAge("12");
		user.setBirthday("1992-10-10");
		user.setUsername("zhangsan");
		Students students = new Students();
		students.setCard("No_1");
		students.setSchool("药校");
		user.setStudents(students);
		JSONArray jsonArray = JSONArray.fromObject(user);
		System.out.println(jsonArray);
	}
}