java根据url获取json对象

package test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;

import org.json.JSONException;
import org.json.JSONObject;
/**
* java根据 url获取 json对象
* @author openks
* @since 2013-7-16
*  需要添加java-json.jar才能运行
*/
public class GetPlaceByIp {

private static String readAll(Reader rd) throws IOException {
StringBuilder sb = new StringBuilder();
int cp;
while ((cp = rd.read()) != -1) {
sb.append((char) cp);
}
return sb.toString();
}

public static JSONObject readJsonFromUrl(String url) throws IOException, JSONException {
InputStream is = new URL(url).openStream();
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText = readAll(rd);
JSONObject json = new JSONObject(jsonText);
return json;
} finally {
is.close();
// System.out.println("同时 从这里也能看出 即便return了，仍然会执行finally的！");
}
}

public static void main(String[] args) throws IOException, JSONException {
//这里调用百度的ip定位api服务 详见 http://api.map.baidu.com/lbsapi/cloud/ip-location-api.htm JSONObject json = readJsonFromUrl("http://api.map.baidu.com/location/ip?ak=F454f8a5efe5e577997931cc01de3974&ip=202.198.16.3");
System.out.println(json.toString());
System.out.println(((JSONObject) json.get("content")).get("address"));
}
}