Php 登录和注册程序获取错误nullpointerxeption_Php_Android_Mysql

Php 登录和注册程序获取错误nullpointerxeption

php android mysql

Php 登录和注册程序获取错误nullpointerxeption,php,android,mysql,Php,Android,Mysql,您好，我正在尝试使用php和mysql开发一个登录和注册程序。我使用的是phpmyadmin，URL是localhost android\u login 当我运行这个程序时，我得到一个类似这样的异常 08-21 15:30:07.560:E/AndroidRuntime9712:致命异常：主 08-21 15:30:07.560:E/AndroidRuntime9712:java.lang.NullPointerException 08-21 15:30:07.560:E/AndroidRunt

您好，我正在尝试使用php和mysql开发一个登录和注册程序。我使用的是phpmyadmin，URL是localhost android\u login

当我运行这个程序时，我得到一个类似这样的异常

08-21 15:30:07.560:E/AndroidRuntime9712:致命异常：主 08-21 15:30:07.560:E/AndroidRuntime9712:java.lang.NullPointerException 08-21 15:30:07.560:E/AndroidRuntime9712:at com.example.ritkigatestadabase.RegisterActivity$1.onClickRegisterActivity.java:65 08-21 15:30:07.560:E/AndroidRuntime9712:at-android.view.view.performClickView.java:4191 08-21 15:30:07.560:E/AndroidRuntime9712:at-android.view.view$PerformClick.runView.java:17229

THIS IS THE RegisterActivity

public class RegisterActivity extends Activity {
        Button btnRegister;
        Button btnLinkToLogin;
        EditText inputFullName;
        EditText inputEmail;
        EditText inputPassword;
        TextView registerErrorMsg;

        // JSON Response node names
        private static String KEY_SUCCESS = "success";
        private static String KEY_ERROR = "error";
        private static String KEY_ERROR_MSG = "error_msg";
        private static String KEY_UID = "uid";
        private static String KEY_NAME = "name";
        private static String KEY_EMAIL = "email";
        private static String KEY_CREATED_AT = "created_at";

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

            // Importing all assets like buttons, text fields
            inputFullName = (EditText) findViewById(R.id.registerName);
            inputEmail = (EditText) findViewById(R.id.registerEmail);
            inputPassword = (EditText) findViewById(R.id.registerPassword);
            btnRegister = (Button) findViewById(R.id.btnRegister);
            btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
            registerErrorMsg = (TextView) findViewById(R.id.register_error);

            // Register Button Click event
            btnRegister.setOnClickListener(new View.OnClickListener() {        
                public void onClick(View view) {
                    String name = inputFullName.getText().toString();
                    String email = inputEmail.getText().toString();
                    String password = inputPassword.getText().toString();
                    UserFunctions userFunction = new UserFunctions();
                    Log.i("funkar","skickar" + name);
                    JSONObject json = userFunction.registerUser(name, email, password);
                    Log.i("funkar","får tillbaka json");


                    // check for login response
                    try {
                        if (json.getString(KEY_SUCCESS) != null) {
                            registerErrorMsg.setText("");
                            String res = json.getString(KEY_SUCCESS);
                            if(Integer.parseInt(res) == 1){
                                // user successfully registred
                                // Store user details in SQLite Database
                                DatabaseHandler db = new DatabaseHandler(getApplicationContext());
                                JSONObject json_user = json.getJSONObject("user");

                                // Clear all previous data in database
                                userFunction.logoutUser(getApplicationContext());
                                db.addUser(json_user.getString(KEY_NAME), json_user.getString(KEY_EMAIL), json.getString(KEY_UID), json_user.getString(KEY_CREATED_AT));                       
                                // Launch Dashboard Screen
                                Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
                                // Close all views before launching Dashboard
                                dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                                startActivity(dashboard);
                                // Close Registration Screen
                                finish();
                            }else{
                                // Error in registration
                                registerErrorMsg.setText("Error occured in registration");
                            }
                        }
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            });

            // Link to Login Screen
            btnLinkToLogin.setOnClickListener(new View.OnClickListener() {

                public void onClick(View view) {
                    Intent i = new Intent(getApplicationContext(),
                            LoginActivity.class);
                    startActivity(i);
                    // Close Registration View
                    finish();
                }
            });
        }
    }

这是用户函数类

public class UserFunctions {

private JSONParser jsonParser;

    // Testing in localhost using wamp or xampp

    private static String loginURL = "http://10.0.2.2/ah_login/";
    private static String registerURL = "http://10.0.2.2/ah_login/";

    private static String login_tag = "login";
    private static String register_tag = "register";

    // constructor
    public UserFunctions(){
        jsonParser = new JSONParser();
    }

    /**
     * function make Login Request
     * @param email
     * @param password
     * */
    //public JSONObject loginUser(String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", login_tag));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));
        JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
        // return json
        // Log.e("JSON", json.toString());
        return json;
    }

    /**
     * function make Login Request
     * @param name
     * @param email
     * @param password
     * */
    public JSONObject registerUser(String name, String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", register_tag));
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));

        // getting JSON Object
        JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
        // return json
        return json;
    }

    /**
     * Function get Login status
     * */
    public boolean isUserLoggedIn(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        int count = db.getRowCount();
        if(count > 0){
            // user logged in
            return true;
        }
        return false;
    }

    /**
     * Function to logout user
     * Reset Database
     * */
    public boolean logoutUser(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        db.resetTables();
        return true;
    }

}

这是JSON解析器

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

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

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "n");
            }
            is.close();
            json = sb.toString();
            Log.e("JSON", json);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);           
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}


Here is the RegisterActivity Class

public class RegisterActivity extends Activity {
        Button btnRegister;
        Button btnLinkToLogin;
        EditText inputFullName;
        EditText inputEmail;
        EditText inputPassword;
        TextView registerErrorMsg;

        // JSON Response node names
        private static String KEY_SUCCESS = "success";
        private static String KEY_ERROR = "error";
        private static String KEY_ERROR_MSG = "error_msg";
        private static String KEY_UID = "uid";
        private static String KEY_NAME = "name";
        private static String KEY_EMAIL = "email";
        private static String KEY_CREATED_AT = "created_at";

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

            // Importing all assets like buttons, text fields
            inputFullName = (EditText) findViewById(R.id.registerName);
            inputEmail = (EditText) findViewById(R.id.registerEmail);
            inputPassword = (EditText) findViewById(R.id.registerPassword);
            btnRegister = (Button) findViewById(R.id.btnRegister);
            btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
            registerErrorMsg = (TextView) findViewById(R.id.register_error);

            // Register Button Click event
            btnRegister.setOnClickListener(new View.OnClickListener() {        
                public void onClick(View view) {
                    String name = inputFullName.getText().toString();
                    String email = inputEmail.getText().toString();
                    String password = inputPassword.getText().toString();
                    UserFunctions userFunction = new UserFunctions();
                    Log.i("funkar","skickar" + name);
                    JSONObject json = userFunction.registerUser(name, email, password);
                    Log.i("funkar","får tillbaka json");


                    // check for login response
                    try {
                        if (json.getString(KEY_SUCCESS) != null) {
                            registerErrorMsg.setText("");
                            String res = json.getString(KEY_SUCCESS);
                            if(Integer.parseInt(res) == 1){
                                // user successfully registred
                                // Store user details in SQLite Database
                                DatabaseHandler db = new DatabaseHandler(getApplicationContext());
                                JSONObject json_user = json.getJSONObject("user");

                                // Clear all previous data in database
                                userFunction.logoutUser(getApplicationContext());
                                db.addUser(json_user.getString(KEY_NAME), json_user.getString(KEY_EMAIL), json.getString(KEY_UID), json_user.getString(KEY_CREATED_AT));                       
                                // Launch Dashboard Screen
                                Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
                                // Close all views before launching Dashboard
                                dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                                startActivity(dashboard);
                                // Close Registration Screen
                                finish();
                            }else{
                                // Error in registration
                                registerErrorMsg.setText("Error occured in registration");
                            }
                        }
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            });

            // Link to Login Screen
            btnLinkToLogin.setOnClickListener(new View.OnClickListener() {

                public void onClick(View view) {
                    Intent i = new Intent(getApplicationContext(),
                            LoginActivity.class);
                    startActivity(i);
                    // Close Registration View
                    finish();
                }
            });
        }
    }

谁能帮帮我吗。谢谢你

基于谷歌的快速搜索，你似乎不应该在应用程序的主线程上执行网络访问来提高响应能力

为网络访问创建另一个线程

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

在与呼叫网络相关的线程/代码所在的代码中使用此代码

将下面的粘贴代码复制到userFunctions.java文件中

public class UserFunctions {

private JSONParser jsonParser;

    // Testing in localhost using wamp or xampp

    private static String loginURL = "http://10.0.2.2/ah_login/";
    private static String registerURL = "http://10.0.2.2/ah_login/";

    private static String login_tag = "login";
    private static String register_tag = "register";

    // constructor
    public UserFunctions(){
        jsonParser = new JSONParser();
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);
    }

    /**
     * function make Login Request
     * @param email
     * @param password
     * */
    //public JSONObject loginUser(String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", login_tag));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));
        JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
        // return json
        // Log.e("JSON", json.toString());
        return json;
    }

    /**
     * function make Login Request
     * @param name
     * @param email
     * @param password
     * */
    public JSONObject registerUser(String name, String email, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", register_tag));
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("email", email));
        params.add(new BasicNameValuePair("password", password));

        // getting JSON Object
        JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
        // return json
        return json;
    }

    /**
     * Function get Login status
     * */
    public boolean isUserLoggedIn(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        int count = db.getRowCount();
        if(count > 0){
            // user logged in
            return true;
        }
        return false;
    }

    /**
     * Function to logout user
     * Reset Database
     * */
    public boolean logoutUser(Context context){
        DatabaseHandler db = new DatabaseHandler(context);
        db.resetTables();
        return true;
    }

}

昨天我有同样的问题，你可以使用允许权限 StrictMode.ThreadPolicy policy=新建StrictMode.ThreadPolicy.Builder.permitAll.build； StrictMode.setThreadPolicypolicy

但最好在长后台进程中使用AsyncTask。仅为获得改进建议

请使用我编辑的answer@Aleksander使用我编辑过的答案eeeees：谢谢你解决了这个错误，但现在我又得到了一个类似这样的例外--08-21 15:30:07.560:E/AndroidRuntime9712:FATAL EXCEPTION:main 08-21 15:30:07.560:E/AndroidRuntime9712:java.lang.NullPointerException 08-21 15:30:07.560:E/AndroidRuntime9712:at com.example.RitkigateStatadabase.RegisterActivity$1.onClickRegisterActivity.java:65 08-21 15:30:07.560:E/AndroidRuntime9712:at android.view.view.performClickView.java:4191 08-21 15:30:07.560:E/AndroidRuntime9712:at android.view.view$PerformClick.runView.java:17229am不明白您还有一个问题吗？根据logcat。错误在RegisterActivity中请在问题中显示您的代码。RegisterActivity请用代码编辑您的问题当然。注册活动对我来说就是一切。你能帮我使用NullPointerExeption吗？为什么不投票？？我认为这是个更好的建议