Java 处理json经常使用代码

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package com.michael;

import static org.junit.Assert.assertEquals;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import org.apache.commons.beanutils.PropertyUtils;
import org.junit.Test;

public class JsonLibTest {
	/**
	 * 将数组转换为json对象
	 */
	// @Test
	public void testArrayToJSON() {
		boolean[] boolArray = new boolean[] { true, false, true };
		JSONArray jsonArray = JSONArray.fromObject(boolArray);
		System.out.println("testArrayToJSON----jsonArray-----" + jsonArray);
	}

	/**
	 * 将集合转换为json
	 */
	// @Test
	public void testListToJSON() {
		List<String> list = new ArrayList<String>();
		list.add("first");
		list.add("second");
		JSONArray jsonArray = JSONArray.fromObject(list);
		System.out.println("testListToJSON---jsonArray----" + jsonArray);
	}

	/**
	 * 将json字符串转换为json对象
	 */
	@Test
	public void testJsonStrToJSON() {
		JSONArray jsonArray = JSONArray.fromObject("['json','is','easy']");
		System.out.println("testJsonStrToJSON---jsonArray----" + jsonArray);
	}

	/**
	 * 将map转换为json对象
	 */
	@Test
	public void testMapToJSON() {
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("name", "json");
		map.put("bool", Boolean.TRUE);
		map.put("int", new Integer(1));
		map.put("arr", new String[] { "a", "b" });
		map.put("func", "function(i){ return this.arr[i]; }");
		JSONObject jsonObject = JSONObject.fromObject(map);
		System.out.println("testJsonStrToJSON---jsonObject----" + jsonObject);
	}

	// 将实体类转换为json
	@Test
	public void testBeadToJSON() {
		Car bean = new Car();
		bean.setId("001");
		bean.setName("hello");
		bean.setDate(new Date());

		List<Car> cars = new ArrayList<Car>();
		cars.add(new Car("AUDI"));
		cars.add(new Car("BMW"));
		cars.add(new Car("QQ"));
		// cars.add(new Person("test"));
		bean.setCars(cars);
		JSONObject jsonObject = JSONObject.fromObject(bean);
		System.out.println("testBeadToJSON---jsonObject----" + jsonObject);

	}

	@Test
	/**
	 * 将json字符串转换为对象
	 * @throws Exception
	 */
	public void testJSONToObject() throws Exception {
		String json = "{name=\"json\",bool:true,int:1,double:2.2,func:function(a){ return a; },array:[1,2]}";
		JSONObject jsonObject = JSONObject.fromObject(json);
		Object bean = JSONObject.toBean(jsonObject);
		assertEquals(jsonObject.get("name"),
				PropertyUtils.getProperty(bean, "name"));
		assertEquals(jsonObject.get("bool"),
				PropertyUtils.getProperty(bean, "bool"));
		assertEquals(jsonObject.get("int"),
				PropertyUtils.getProperty(bean, "int"));
		assertEquals(jsonObject.get("double"),
				PropertyUtils.getProperty(bean, "double"));
		assertEquals(jsonObject.get("func"),
				PropertyUtils.getProperty(bean, "func"));

		List arrayList = (List) JSONArray.toCollection(jsonObject
				.getJSONArray("array"));
		for (Object object : arrayList) {
			System.out.println(object);
		}

	}
}