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);
}

}
}