Question

我正在尝试从一个简单的Android应用发送消息并将其保存在服务器中。

这是服务器

<!DOCTYPE html>
<html lang="en">
    <head>

        <title>
            Title...
        </title>

    </head>

    <body>
        <section style="text-align:center;">

        <?php 

        $data = "";

        if ($_SERVER["REQUEST_METHOD"] == "POST")
        {

            ob_start();
            var_dump($_POST['data']);
            $message = ob_get_contents();
            $my_file = 'file.txt';
            $handle = fopen($my_file, 'w') or die('Cannot open file:  '.$my_file);
            fwrite($handle, $message);
            fclose($handle);

        }
        ?>

         <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">  
          message: <br/> 
          <input type="text" name="data" value="<?php echo $data;?>"><br/>
          <input type="submit" name="submit" value="Submit">  
        </form> 

        </section>

    </body>
</html>

该应用与https://developer.android.com/training/basics/firstapp/starting-activity中的第一个应用相同，另外还提供了互联网许可和一些用于发送消息的代码

公共类DisplayMessageActivity扩展了AppCompatActivity {

private static final String myURL = "https://[mywebsite].000webhostapp.com/index.php";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display_message);

    // Get the Intent that started this activity and extract the string
    Intent intent = getIntent();
    String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

    // Capture the layout's TextView and set the string as its text
    TextView textView = findViewById(R.id.textView);
    textView.setText(message);

    URL url;

    StringBuilder sb = new StringBuilder();

    try {
        url = new URL(myURL);
        HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
        conn.setRequestMethod("POST");
        conn.setDoOutput( true );
        conn.setDoInput( true );

        OutputStream os = conn.getOutputStream();

        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));

        HashMap<String, String> params = new HashMap<>();
        params.put("data", message);
        writer.write(getPostDataString(params));

        writer.flush();
        writer.close();
        os.close();

        int responseCode = conn.getResponseCode();

        if (responseCode == HttpsURLConnection.HTTP_OK) {
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            sb = new StringBuilder();
            String response;

            while ((response = br.readLine()) != null) {
                sb.append(response);
            }

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

}

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();
}

}

页面本身可以创建预期的文件，但该应用程序无法创建，我编写了消息，按send键，它显示了带有消息的显示屏，没有任何其他错误或异常。我在做什么错了？

编辑：网络部分必须在另一个线程中完成

protected void onCreate(Bundle savedInstanceState) {
        ...
        textView.setText(message);

        callAsyncTask();
}
private void callAsyncTask() {

        class ATaskCaller extends AsyncTask<Void, Void, String> {

            @Override
            protected String doInBackground(Void... voids) {
                ...
                [network stuff]
                ...
            }
        }
        ATaskCaller atc = new ATaskCaller();
        atc.execute();
}

Answer 1

确保您的服务器接受cors。

您正在尝试发布信息，因此您的服务器应该接受它。响应标头应包含：

访问控制允许方法：POST

访问控制允许来源：*

https://developer.mozilla.org/pt-BR/docs/Web/HTTP/Controle_Acesso_CORS

如何通过PHP页面传达Android应用程序？

1 个答案: