五分钟带你学会用java解析json字符串

{
    "firstName": "John",
    "lastName": "Smith",
    "age": 25,
    "address": {
        "streetAddress": "21 2nd Street",
        "city": "New York",
        "state": "NY",
        "postalCode": 10021
    },
    "phoneNumbers": [
        {
            "type": "home",
            "number": "212 555-1234"
        },
        {
            "type": "fax",
            "number": "646 555-4567" 
        }
    ] 
}

//引入解析json常用的包
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.*;

//将jsonStr中的数据提取出来，转化成Person类，Person类已经根据json的格式设定好
public static Person jsonParse(String jsonStr){
	//将json string转化为json object
	JSONObject jo = new JSONObject(jsonStr);
	//初始化目标值
	Person person = new Person();
	//获取值为String类型的成员变量
	String firstName = jo.getString("firstName");
	String lastName = jo.getString("lastName");
	person.setFirstName(firstName);
	person.setLastName(lastName);
	//获取值为int类型的成员变量
	int age = jo.getInt("age");
	person.setAge(age);
	//获取值为Object类型的成员变量（如上套娃）
	//Address类已经根据json的格式设定好
	JSONObject addressObj = jo.getJSONObject("address");
	Address address = new Address();
	String streetAddress = addressObj.getString("addressObj");
	address.setStreetAddress(streetAddress);
	...
	person.setAddress(address);
	//获取值为array类型的成员变量
	//PhoneNumber类已经根据json的格式设定好
	List<PhoneNumber> phoneNumbers = new ArrayList<PhoneNumber>();
	JSONArray phoneNumbersjson = jo.getJSONArray("phoneNumbers");
	for(int i=0;i<phoneNumbersjson.length();i++){
		//套娃解析其中每一个对象
		PhoneNumber phoneNumber = new PhoneNumber();
		JSONObject phoneNumberObj = phoneNumbersjson.getJSONObject(i);
		String type = phoneNumberObj.getString("type");
		phoneNumber.setType(type);
		String number = phoneNumberObj.getString("number");
		phoneNumber.setType(number);
		//将解析好的对象加入数组
		phoneNumbers.add(phoneNumber);
	}
	person.setPhoneNumbers(phoneNumbers);
}