java HttpURLConnection 中用 userid转openid

java中用HttpURLConnection方法把userid转openid

具体可看api    http://qydev.weixin.qq.com/wiki/index.php?title=Userid与openid互换接口

不过 需要使用post提交

那么post的参数根据api来

{
"userid": "zhangsan",
"agentid": 1
}

那么该如何组装post的参数呢,之前组装参数的时候一直有问题，发现需要将参数组装成json格式才可以

如下方可成功

String param = "{\"userid\":\"" + userid+ "\",\"agentid\":\"1\"}";

以下不能成功

String param = "userid=" + userid + "&agentid=1";

具体实现如下,输出结果{"errcode":0,"errmsg":"ok","openid":"sdf","appid":"qwe"}

<pre name="code" class="java">import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class Test {
public static void main(String[] args) throws Exception {
String access_token = "...";
post("https://qyapi.weixin.qq.com/cgi-bin/user/convert_to_openid?access_token="+access_token,
"userid");
}

public static String post(String urlPath, String userid) throws Exception {
// 设置参数
String param = "{\"userid\":\"" + userid + "\",\"agentid\":\"1\"}";
// 建立连接
URL url = new URL(urlPath);
HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
httpConn.setDoOutput(true); // 需要输出
httpConn.setDoInput(true); // 需要输入
httpConn.setUseCaches(false); // 不允许缓存
httpConn.setRequestMethod("POST");
// 设置请求属性
httpConn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
// 维持长连接
httpConn.setRequestProperty("Connection", "Keep-Alive");
httpConn.setRequestProperty("Charset", "UTF-8");
// 连接,也可以不用明文connect，使用下面的httpConn.getOutputStream()会自动connect
httpConn.connect();
// 建立输入流，向指向的URL传入参数
httpConn.getOutputStream().write(param.getBytes());// 输入参数

// 获得响应状态
int resultCode = httpConn.getResponseCode();
if (HttpURLConnection.HTTP_OK == resultCode) {
StringBuffer sb = new StringBuffer();
String readLine = new String();
BufferedReader responseReader = new BufferedReader(
new InputStreamReader(httpConn.getInputStream(), "UTF-8"));
while ((readLine = responseReader.readLine()) != null) {
sb.append(readLine).append("\n");
}
responseReader.close();
System.out.println(sb.toString());
return sb.toString();
}
return "error";
}

}