使用 Android 应用程序 (Java) 登录网站

Question

我目前正在尝试制作一个应用程序，允许您登录到您的帐户并查看需要显示的任何数据。

我没有使用 webview，而是为了显示信息，我将从 HTML 解析数据，然后从那里开始工作，提取我需要显示的数据。我将从下面的应用中 post 代码。

我需要帮助的是弄清楚如何使用我的应用程序登录网站。

基本上，步骤如下：

1.Enter 用户名

2.Enter 密码

3.Press 登录按钮

4.Send 网站用户名和密码

5.If - 网站 returns "Successful login"，继续并解析 HTML 的下一页，否则 - 显示 "Wrong username or password"

但是，我不知道如何让我的应用程序登录，或者至少在网站的登录字段中输入数据，这样我至少可以通过某种方式获得响应。

我对此很陌生，所以请至少指出正确的方向，以便我弄明白。非常感谢。

    package com.example.app;

    import androidx.appcompat.app.AppCompatActivity;

    import android.content.Intent;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;

    import org.jsoup.Jsoup;
    import org.jsoup.nodes.Document;

    public class MainActivity extends AppCompatActivity {
        String data;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            TextView LoginTitle = findViewById(R.id.tvLoginTitle);
            EditText Username = findViewById(R.id.etUsername);
            EditText Password = findViewById(R.id.etPass);
            Button Login = findViewById(R.id.btLogin);

            Login.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    new Parse().execute();
                    Intent intent = new Intent(MainActivity.this,UserAccount.class);
                    intent.putExtra("data",data);
                    startActivity(intent);
                }
            });

        }

        public class Parse extends AsyncTask<Void, Void, Void> {
            @Override
            protected Void doInBackground(Void... voids) {
                try {
                    Document WebPage = Jsoup.connect("https://myurl").get();
                    Log.d("data", WebPage.toString());
                    data=WebPage.toString();
                } catch(Exception e) {
                    e.printStackTrace();
                }
                return null;
            }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            //Used in guide, however, my implementation of the app doesn't seem to need this.
        }
    }
}

Answer 1

我不确定您在此处记录网页内容的目的是什么。您首先需要做的是检查 "browser" 是否启用了 Javascript 但在您的情况下这没有实际意义，因为您使用的是自己的 WebView。只检查是否启用了 JS 仍然是明智的。

下一步显然涉及使用 JS，因为我要求您检查它是否已启用。这是代码，但请注意我没有对此进行测试，但这是朝着正确方向迈出的一步：

    public void loginUser(View view) {

        InputMethodManager inputMan = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(layout.getWindowToken(), 0);


        webView.loadUrl("https://yourwebsite.net");
        webView.setVisibility(View.INVISIBLE);
        webView.setWebViewClient(new WebViewClient() {

            public void onPageFinished(WebView view, String url) {
                webView.loadUrl("javascript: {" + "document.getElementById('login_account').value = '" + "USERNAME" + "';" + "document.getElementById('login_password').value = '" + "PASSWORD" + "';" + "document.getElementById('submit').click();" + "};");
                 }

            public void onPageFinished2(WebView view, String url) {
                webView.loadUrl(url);
            }
        });

        webView.clearCache(true);
        webView.clearHistory();


    WebView webView2 = (WebView) this.findViewById(R.id.web_view);

    String url = "https://yourwebsite.net";
    webView2.loadUrl(url);

}

一些注意事项：为了安全起见，请将 login_account 和 login_password 的值更改为人们不容易猜到的值。

Answer 2

解决方法如下：

class HTTPRequest implements Runnable {

    private URL url;
    private User user;
    private Handler handler;
    private String cookie;

    //**REDEFINED CONSTRUCTOR
    HTTPRequest(Handler in_handler, User in_user) {
        try {
                        url = new URL("https://yoururl.com");

            handler = in_handler;
            user = in_user;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        try {
            //**Preparing to open connection
            //**Using POST method
            //**Enabling Input & Output
            HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoInput(true);
            conn.setDoOutput(true);

            //**Setting Headers to send with POST request
            conn.setRequestProperty("Accept", "text/html");
            conn.setRequestProperty("Accept", "text/xml");
            conn.setRequestProperty("Cookie", "upassword=" + user.getPasswordHashed() + "; ulogin=" + user.getUsername());
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("charset", "UTF-8");
            conn.setRequestProperty("User-Agent", "Mozilla/5.0");

            //**READING RESPONSE FROM THE SERVER:
            //**IF LOGIN WAS SUCCESSFUL, SEND MESSAGE WITH XML DATA BACK TO UI THREAD, ELSE SEND NULL TO UI THREAD
            BufferedReader input = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            if (isLoginSuccess(input)) {
                StringBuilder response = new StringBuilder();
                String tempString;
                while ((tempString = input.readLine()) != null) {
                    response.append(tempString);
                }
                input.close();
                conn.disconnect();

                Message msg = Message.obtain();
                msg.obj = response.toString();
                handler.sendMessage(msg);
            } else if (!isLoginSuccess(input)) {
                input.close();
                conn.disconnect();
                Message msg = Message.obtain();
                msg.obj = "Wrong";
                handler.sendMessage(msg);
            }

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

    //**LOGIN IS SUCCESSFUL WHEN THE RESPONSE'S FIRST LINE EQUALS XML DECLARATION
    //**RETURNS TRUE IF THAT IS THE CASE, MEANING YOU HAVE SUCCESSFULLY LOGGED IN
    private boolean isLoginSuccess(BufferedReader input) throws IOException {
        String LoginSuccess = "<?xml version=\"1.0\" encoding=\"utf-8\"?>";

        String response = input.readLine();
        return response.equals(LoginSuccess);
    }
}

MainActivity.java:

public class MainActivity extends AppCompatActivity {

    public static final String EXTRA_MESSAGE = "Message 1";
    public static final String EXTRA_MESSAGE_2 = "Message 2";
    Handler mainHandler;
    Thread thread;
    User user;

    EditText etUsername;
    EditText etPassword;
    CheckBox cbRememberMe;
    Button btLogin;

    SharedPreferences preferences;
    SharedPreferences.Editor SPEditor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setTheme(R.style.LoginPageTheme);
        setContentView(R.layout.activity_main);

        //**DECLARATION OF SHARED PREFERENCES
        preferences = getApplicationContext().getSharedPreferences("Preferences", MODE_PRIVATE);
        SPEditor = preferences.edit();
        SPEditor.apply();

        //**HANDLER INSTANTIATING AND HANDLING MESSAGES FROM HTTPRequest
        mainHandler = new Handler(Looper.getMainLooper()) {
            @Override
            public void handleMessage(@NonNull Message msg) {
                String message = msg.obj.toString();
                thread.interrupt();
                if (!message.equals("Wrong")) {
                    if (cbRememberMe.isChecked()) {
                        user.RememberLoginSuccess(preferences);
                    }
                    Intent intent = new Intent(getApplicationContext(), ProfilePageActivity.class);
                    intent.putExtra(EXTRA_MESSAGE, message);
                    intent.putExtra(EXTRA_MESSAGE_2, user);
                    startActivity(intent);
                    finish();
                } else {
                    etUsername.setError("Wrong username or password");
                    etUsername.setText("");
                    etPassword.setText("");
                }
            }
        };

        etUsername = findViewById(R.id.et_username);
        etPassword = findViewById(R.id.et_password);
        cbRememberMe = findViewById(R.id.cb_rememberMe);
        btLogin = findViewById(R.id.bt_login);

        btLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String temp_user = etUsername.getText().toString();
                String temp_pass = etPassword.getText().toString();
                if (!TextUtils.isEmpty(temp_user) && !TextUtils.isEmpty(temp_pass)) {
                    user = new User(etUsername.getText().toString(), etPassword.getText().toString());
                    thread = new Thread(new HTTPRequest(mainHandler, user));
                    thread.start();
                } else {
                    etUsername.setError("Please, fill-out the form");
                    etUsername.setText("");
                    etPassword.setText("");
                }
            }
        });
    }
}

使用 Android 应用程序 (Java) 登录网站

Logging into a website using Android app (Java)

java

android

android-webservice