org.json.jsonexception:java.lang.string类型的value< br不能转换为j

Question

我正在尝试在Android Studio中开发Android应用程序，以将数据从注册用户活动发送到数据库中。这个想法是用户在所有必需的信息中键入的，并单击"寄存器"按钮，数据应转到数据库，登录活动应该重新出现。但是，当我单击上的"寄存器"按钮时

下面是我的注册用户活动代码：

package com.example.vi5h.split;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.toolbox.Volley;
import org.json.JSONException;
import org.json.JSONObject;
public class RegisterUserActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register_user);
    final EditText etFullName = (EditText) findViewById(R.id.etFullName);
    final EditText etUsername = (EditText) findViewById(R.id.etUsername);
    final EditText etPassword = (EditText) findViewById(R.id.etPassword);
    final EditText etEmail = (EditText) findViewById(R.id.etEmail);
    final Button btnRegister = (Button) findViewById(R.id.btnRegister);
    btnRegister.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final String name = etFullName.getText().toString();
            final String username = etUsername.getText().toString();
            final String password = etPassword.getText().toString();
            final String email = etEmail.getText().toString();
            Response.Listener<String> responseListener = new Response.Listener<String>(){
                @Override
                public void onResponse(String response) {

                    try {
                        JSONObject jsonResponse = new JSONObject(response);
                        boolean success = jsonResponse.getBoolean("success");
                        if (success){
                            Intent intent = new Intent(RegisterUserActivity.this, LoginActivity.class);
                            RegisterUserActivity.this.startActivity(intent);
                        }else {
                            AlertDialog.Builder builder = new AlertDialog.Builder(RegisterUserActivity.this);
                            builder.setMessage("Register Failed")
                                    .setNegativeButton("Retry", null)
                                    .create()
                                    .show();
                        }

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

                }
            };

            RegisterRequest registerRequest = new RegisterRequest(name, username, email, password, responseListener);
            RequestQueue queue = Volley.newRequestQueue(RegisterUserActivity.this);
            queue.add(registerRequest);

        }
    });

}
}

下面是我的注册请求类代码：

package com.example.vi5h.split;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;
import java.util.HashMap;
import java.util.Map;

public class RegisterRequest extends StringRequest {
private static final String REGISTER_REQUEST_URL = "https://split.000webhostapp.com/Register.php";
private Map<String, String> params;
public RegisterRequest(String name, String username, String email, String password, Response.Listener<String> listener)
{
    super(Method.POST, REGISTER_REQUEST_URL, listener, null);
    params = new HashMap<>();
    params.put("name", name);
    params.put("username", username);
    params.put("email", email);
    params.put("password", password);
}

@Override
public Map<String, String> getParams() {
    return params;
}
}

下面是我的 php脚本（register.php）：

<?php
$con = mysqli_connect("localhost", "id2833909_split421", "pass321", "id2833909_splitw");
$name = $_POST["name"];
$email = $_POST["email"];
$username = $_POST["username"];
$password = $_POST["password"];
$statement = mysqli_prepare($con, "INSERT INTO user (name, username, email, password) VALUES (?, ?, ?, ?)");
mysqli_stmt_bind_param($statement, "siss", $name, $username, $email, $password);
mysqli_stmt_execute($statement);
$response = array();
$response["success"] = true;  
echo json_encode($response);
?>

和下面的详细是在我轻拍 register 按钮之后在logcat上丢下的错误： https://imgur.com/b8x0Su6

Answer 1

如果您访问https://split.000webhostapp.com/register.php在Web浏览器中，则会返回损坏的内容。它不是一个完整的网页，而是一堆错误消息：

<br />
<b>Notice</b>:  Undefined index: name in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>4</b><br />
<br />
<b>Notice</b>:  Undefined index: email in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>5</b><br />
<br />
<b>Notice</b>:  Undefined index: username in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>6</b><br />
<br />
<b>Notice</b>:  Undefined index: password in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>7</b><br />
<br />
<b>Warning</b>:  mysqli_stmt_bind_param() expects parameter 1 to be mysqli_stmt, boolean given in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>9</b><br />
<br />
<b>Warning</b>:  mysqli_stmt_execute() expects parameter 1 to be mysqli_stmt, boolean given in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>10</b><br />
{"success":true}

该响应的前三个字符是<br。这些恰好是JSON解析器在错误消息中抱怨的前三个字符。因此，我的猜测是，Web服务器正在响应您的凌空请求时发送相同的破碎内容。

因此，请看一下response，看看您所得到的纯文本。然后，解决response指示的任何问题。