使用Android 5.1将数据插入MySql数据库

Question

来自Android：

  

org.apache.http类和 android.net.http.AndroidHttpClient 类已在Android 5.1中弃用。这些类不再被维护，您应该尽快使用这些API将任何应用程序代码迁移到 URLConnection 类。

现在，在Android 5.1中，http类已弃用，如何使用URLConnection将数据插入MySQL数据库？

我目前尝试使用https://stackoverflow.com/a/29561084/2229701中的Fahims代码，但我无法使其正常工作。

insert.php

<?php
// configuration
$dbhost     = "localhost";
$dbname     = "test";
$dbuser     = "root";
$dbpass     = "";

// database connection
$conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);

// new data
$firstname = $_POST['firstname'];

// query
$sql = "INSERT INTO students (firstname) VALUES (:firstname)";
$q = $conn->prepare($sql);
$q->execute(array(':firstname'=>$firstname));


?>

insert.php位于：http：// 192.168.0.5/app/insert.php

这是我目前在MainActivity中的代码：

public void postBtnClicked(View view){

    HashMap m = new HashMap();
    m.put("firstname", "sam");

    performPostCall("http://192.168.0.5/app/insert.php", m);

}

public String performPostCall(String requestURL, HashMap<String, String> postDataParams) {

    URL url;
    String response = "";
    try {
        url = new URL(requestURL);

        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(15000);
        conn.setConnectTimeout(15000);
        conn.setRequestMethod("POST");
        conn.setDoInput(true);
        conn.setDoOutput(true);


        OutputStream os = conn.getOutputStream();
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));
        writer.write(getPostDataString(postDataParams));

        writer.flush();
        writer.close();
        os.close();
        int responseCode=conn.getResponseCode();

        if (responseCode == HttpsURLConnection.HTTP_OK) {
            String line;
            BufferedReader br=new BufferedReader(new InputStreamReader(conn.getInputStream()));
            while ((line=br.readLine()) != null) {
                response+=line;
            }
        }
        else {
            response="";

        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    return response;
}

private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
    StringBuilder result = new StringBuilder();
    boolean first = true;
    for(Map.Entry<String, String> entry : params.entrySet()){
        if (first)
            first = false;
        else
            result.append("&");

        result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
    }

    return result.toString();
}