无法连接数据库

Question

我正在尝试使用eclipse创建一个应用程序。在用户注册页面中，我输入了所有需要的数据，然后单击提交按钮，出现消息“不幸的是，您的eclipse已停止”。这条消息意味着什么，如何解决它？

 public class UserRegister extends Activity {

JSONParser jsonParser = new JSONParser();
EditText inputName;
EditText inputUsername;
EditText inputEmail;
EditText inputPassword;
RadioButton button1;
RadioButton button2;
Button button3;
int success = 0;

// url to create new product
private static String url_register_user = "http://192.168.1.100/MEMS/add_user.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_user_register);

    // Edit Text
    inputName = (EditText) findViewById(R.id.nameTextBox);
    inputUsername = (EditText) findViewById(R.id.usernameTextBox);
    inputEmail = (EditText) findViewById(R.id.emailTextBox);
    inputPassword = (EditText) findViewById(R.id.pwTextBox);

    // Create button
    //RadioButton button1 = (RadioButton) findViewById(R.id.studButton);
    // RadioButton button2 = (RadioButton) findViewById(R.id.shopownerButton);
    Button button3 = (Button) findViewById(R.id.regSubmitButton);

    // button click event
    button3.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {

            String name = inputName.getText().toString();
            String username = inputUsername.getText().toString();
            String email = inputEmail.getText().toString();
            String password = inputPassword.getText().toString();

                   if(name.contentEquals("")||username.contentEquals("")||email.contentEquals("")||password.contentEquals(""))
            {
                AlertDialog.Builder builder = new AlertDialog.Builder(UserRegister.this);

                // 2. Chain together various setter methods to set the dialog characteristics
                builder.setMessage(R.string.nullAlert)
                   .setTitle(R.string.alertTitle);

                builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // User clicked OK button
                   }
               });

            // 3. Get the AlertDialog from create()
            AlertDialog dialog = builder.show();
            }
            else
            {
                new RegisterNewUser().execute();
            }

        }
    });
}


       class RegisterNewUser extends AsyncTask<String, String, String>{
   protected String doInBackground(String... args) {
       String name = inputName.getText().toString();
       String username = inputUsername.getText().toString();
       String email = inputEmail.getText().toString();
       String password = inputPassword.getText().toString();

       // Building Parameters
       List<NameValuePair> params = new ArrayList<NameValuePair>();
       params.add(new BasicNameValuePair("name", name));
       params.add(new BasicNameValuePair("username", username));
       params.add(new BasicNameValuePair("email", email));
       params.add(new BasicNameValuePair("password", password));

       // getting JSON Object
       // Note that create product url accepts POST method
       JSONObject json = jsonParser.makeHttpRequest(url_register_user,
                           "GET", params);
                   // check log cat for response
       Log.d("Send Notification", json.toString());

       try
           {
                   int success = json.getInt(TAG_SUCCESS);

                   if (success == 1)
                   {
                       // successfully created product
                    Intent i = new Intent(getApplicationContext(), StudentLogin.class);
                    startActivity(i);
                    finish();
                   }

                   else
                   {
                       // failed to register

                   }
           }

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

我的php文件：

<?php

  /*
   * Following code will create a new product row
   * All product details are read from HTTP Post Request
   */

  // array for JSON response
  $response = array();
   // include db connect class
   require_once __DIR__ . '/db_connect.php';

// connecting to db
     $db = new DB_CONNECT();

     // check for required fields
     if (isset($_GET['name']) && isset($_GET['username']) && isset($_GET['email']) &&             isset($_GET['password'])) {

$name = $_GET['name'];
$username = $_GET['username'];
$email = $_GET['email'];
$password = $_GET['password'];


// mysql inserting a new row
$result = mysql_query("INSERT INTO register(name, username, email, password) VALUES('$name', '$username', '$email', '$password')");

// check if row inserted or not
if ($result) {
    // successfully inserted into database
    $response["success"] = 1;
    $response["message"] = "You are successfully registered to MEMS.";

    // echoing JSON response
    echo json_encode($response);
}
else {
    // failed to insert row
    $response["success"] = 0;
    $response["message"] = "Oops! An error occurred.";

    // echoing JSON response
    echo json_encode($response);
}
} else {
      // required field is missing
      $response["success"] = 0;
      $response["message"] = "Required field(s) is missing";

        // echoing JSON response
        echo json_encode($response);
        }
           ?>

Answer 1

在代码中将比较方法更改为equals()而不是contentEquals()

因为String#equals()不仅比较字符串的内容，而且还检查另一个对象是否也是String的实例。String#contentEquals() methods仅比较内容(字符序列)，而不检查另一个对象是否也是String的实例。它可以是任何东西，只要它是CharSequence的实现或StringBuffer的实例。

所以像这样修改你的代码

if(name.equals("")||username.equals("")||email.equals("")||password.equals(""))
 {
     ....
}