java - HTTPEntity 给出空值

Question

我的 Android 应用程序上有一个忘记密码的页面。如果我没有输入电子邮件，它会从服务器返回正确的响应，如果我输入的电子邮件是在我们的数据库中找到的，那么它会向用户发送一封电子邮件并从服务器返回正确的响应。但是，如果我输入电子邮件但在我们的数据库中找不到，当我打电话时

HttpEntity entity = response.getEntity();

实体是空值。我不确定为什么它适用于其中两种情况，但不适用于第三种情况。

有人知道为什么会这样吗？我的代码如下

安卓代码:

private void accessURL(String url) {
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(url);

    if (url.equalsIgnoreCase(Global.forgotPasswordURL)) {
        InputStream is = null;
        ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        nameValuePairs.add(new BasicNameValuePair("email", email.getText().toString()));

        try {
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();

            if(entity != null){
                is = entity.getContent();
                String jsonResult = inputStreamToString(is).toString();
                if (jsonResult.equalsIgnoreCase("Please enter your Email")) {
                    new AlertDialog.Builder(this).setTitle("Please Enter Your Email Address")
                            .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int which) {
                                    // continue with delete
                                }
                            }).show();
                }else if(jsonResult.equalsIgnoreCase("Email Address Not Found")){
                    new AlertDialog.Builder(this).setTitle("The Email Address You Entered has not Been Found").setMessage("Make sure that you entered your email correctly.")
                    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {

                        }
                    }).show();
                }else{
                    new AlertDialog.Builder(this).setTitle("Your Email Has Been Found!").setMessage("Check the email you provied for further instructions on resetting your password.")
                    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {

                        }
                    }).show();
                }
            }else{
                Log.d("Null", "null");
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

PHP 代码:

if (isset($_POST["email"]) && !empty($_POST['email'])) {
        $con=mysqli_connect("localhost","***********","******","*******");
        $email = $_POST['email'];
        $query = mysql_query("SELECT * FROM users WHERE email = '$email'");
        $query2 = mysql_query("SELECT * FROM tempusers WHERE email = '$email'");
        $ans = mysql_num_rows($query);
        $ans2 = mysql_num_rows($query2);
        $str = $ans . " " . $ans2;
        if(mysql_num_rows($query) == 0 && mysql_num_rows($query2) == 0){
            sendResponse(205, "Email Address Not Found");
            return false;
        }
        $temp = false;
        if(mysql_num_rows($query2) != 0){
            $temp = true;
            $query1 = mysql_query("SELECT * FROM tempusers WHERE email = '$email'");
            $row = mysql_fetch_array($query1);
            mailUser($email, $row['firstname'], $temp);

            sendResponse(200, "Email Address Found".$str);
            return true;
        }else{
            $query1 = mysql_query("SELECT * FROM users WHERE email = '$email'");
            $row = mysql_fetch_array($query1);
            mailUser($email, $row['firstname'], $temp);

            sendResponse(200, "Email Address Found".$str);
            return true;
        }
    }
    sendResponse(400, 'Please enter your Email');
    return false;

如果能帮助解决这个问题，我们将不胜感激，谢谢!

Answer 1

据我了解，它的行为符合 HttpEntity 的规范对于 205 个响应。这是规范所说的:

HTTP messages can carry a content entity associated with the request or response. Entities can be found in some requests and in some responses, as they are optional. Requests that use entities are referred to as entity enclosing requests. The HTTP specification defines two entity enclosing request methods: POST and PUT. Responses are usually expected to enclose a content entity. There are exceptions to this rule such as responses to HEAD method and 204 No Content, 304 Not Modified, 205 Reset Content responses.

如果找不到电子邮件，您可以在 PHP 中发送 404 响应代码并检查您的 Java 代码:

if(response.getStatusLine().getStatusCode() == 404){
  //email was not found
}