Android HttpURLConnection 写入 post 数据

Question

我正在尝试通过 HttpURLConnection 发送 post 数据，但它似乎没有发送 post 数据。

我可以在尝试发送 POST 请求之前立即通过 Toast 输出数据，但是当我在服务器端检查时它会连接到 PHP 文件，但是POST 数据为空。

所以，我知道数据存在于 jsonObject 中。我也知道它进入了 try catch 语句，但是当我连接时它没有被正确发送或接收。

try {
        URL url = new URL(emailURL);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        conn.setDoOutput(true);

        conn.setRequestMethod( "POST" );
        conn.setRequestProperty( "Content-Type", "application/json");
        conn.setRequestProperty( "charset", "utf-8");
        conn.setRequestProperty( "Content-Length", Integer.toString( jsonObject.toString().length() ));
        conn.setUseCaches( false );

        OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

        wr.write(jsonObject.toString());

          wr.close();

        BufferedReader reader = null;
        reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        StringBuilder sb = new StringBuilder();
        String line = null;

        // Read Server Response
        while ((line = reader.readLine()) != null) {
            // Append server response in string
            sb.append(line + "\n");
        }

        String text = "";
        text = sb.toString();



    } catch (Exception e) {

        throw new RuntimeException(e);
    }

Answer 1

尝试添加方法以确保它确实连接到您的服务器。

修改您的代码，如：

    int responseCodeFromServer = -1;
    try {
         responseCodeFromServer=conn.getResponseCode();
    } catch (Exception e){
         e.printStackTrace();
    }

    if (responseCodeFromServer == HttpsURLConnection.HTTP_OK){
         BufferedReader reader = null;
         reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
         StringBuilder sb = new StringBuilder();
        String line = null;

       // Read Server Response
       while ((line = reader.readLine()) != null) {
          // Append server response in string
          sb.append(line + "\n");
       }

       String text = "";
       text = sb.toString();
    }

因此，如果在连接到您的服务器时出现问题，您将看到异常。

Answer 2

在您获得响应代码或输入或错误流之前，什么都不会发生。您必须执行以下操作之一。

注意您不需要设置内容长度。 Java 为您做到这一点。同理，setDoOutput(true)设置请求方式为POST.

Answer 3

conn.setRequestProperty( "charset", "utf-8");
conn.setRequestProperty( "Content-Length", Integer.toString(jsonObject.toString().length() ));
conn.setUseCaches( false );

conn.connect(); // this is missing in your code

OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

Android HttpURLConnection 写入 post 数据

Android HttpURLConnection write post data

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android

httpurlconnection