Question

我正在为我的应用程序使用websocket client程序。在主要的Activity I中，我连接到websocket客户端并执行所有onMessage，onOpen就像抽象mathod一样。我还有两个名为Login and Register活动的活动。我将Login ativity中的用户详细信息发送到服务器以进行验证。来自服务器I在onMessage抽象方法中接收MainActivity中的消息。我需要在Login Activity中使用该消息。请解释我如何实现这一目标？如果我在这里复制我的问题，请原谅我，并指导我做出正确答案。

这是我的 MainActivity ：

package org.asperohgedgetws.a7.hgadgetws;

import android.app.Activity;
import android.app.Fragment;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.handshake.ServerHandshake;
import java.net.URI;
import java.net.URISyntaxException;

import android.widget.Button;
import android.widget.Toast;
import android.content.Intent;


public class MainActivity extends Activity implements View.OnClickListener {
Button bLogout;
public static TextView tvReceived;
UserLocalStore userLocalStore;
public static WebSocketClient mWebSocketClient;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    bLogout = (Button) findViewById(R.id.bLogout);
    bLogout.setOnClickListener(this);
    userLocalStore = new UserLocalStore(this);
    tvReceived = (TextView) findViewById(R.id.tvRecieved);

    connectWebSocket();
}
@Override
protected void onStart() {
    super.onStart();
    if (authenticate()){
        displayUserDetails();
    } else{
        Toast.makeText(getApplicationContext(), "Not Registered User :(", Toast.LENGTH_SHORT).show();
        startActivity(new Intent(MainActivity.this,Login.class));
    }
}

private boolean authenticate(){
    return userLocalStore.getUserLoggedIn();
}

private void displayUserDetails(){
    User user = userLocalStore.getLoggedInUser();
}

@Override
public void onClick(View v) {
    switch(v.getId()){
        case R.id.bLogout:
            startActivity(new Intent(this,Login.class));
            userLocalStore.clearUserData();
            userLocalStore.setUserLoggedIn(false);
            Toast.makeText(getApplicationContext(), "Logout :)", Toast.LENGTH_SHORT).show();

            break;

    }
}

public void connectWebSocket() {
    URI uri;
    try {
        uri = new URI("ws://xxx.xxx.xxx:xxxx");
    } catch (URISyntaxException e) {
        e.printStackTrace();
        return;
    }

    mWebSocketClient = new WebSocketClient(uri) {
        @Override
        public void onOpen(ServerHandshake serverHandshake) {
            Log.i("Websocket", "Opened");
            //mWebSocketClient.send("Hello from " + Build.MANUFACTURER + " " + Build.MODEL);
            //mWebSocketClient.send("{\"1512BD002\":\"SO@0\":\"2\"}");
        }

        @Override
        public void onMessage(String s) {
            //final String message = s;
             final String WSmessage = s;
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getApplicationContext(), WSmessage, Toast.LENGTH_SHORT).show();
                    tvReceived.setText(WSmessage);
                    Log.i("Websocket_Message", WSmessage);
                    //TextView textView = (TextView)findViewById(R.id.messages);
                    //textView.setText(textView.getText() + "\n" + message);
                }
            });
        }

        @Override
        public void onClose(int i, String s, boolean b) {
            Log.i("Websocket", "Closed " + s);
        }

        @Override
        public void onError(Exception e) {
            Log.i("Websocket", "Error " + e.getMessage());
        }
    };
    mWebSocketClient.connect();
}

public void sendMessage(View view) {
 //   EditText editText = (EditText)findViewById(R.id.message);
   // mWebSocketClient.send(editText.getText().toString());
    //editText.setText("");
}
}

LoginActivity 包org.asperohgedgetws.a7.hgadgetws;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.gson.Gson;
import android.app.ProgressDialog;
import java.util.LinkedHashMap;
import java.util.Map;

public class Login extends AppCompatActivity implements View.OnClickListener {

Button bLogin;
EditText etUsername, etPassword;
TextView tvRegisterLink;
UserLocalStore userLocalStore;

/**
 * ATTENTION: This was auto-generated to implement the App Indexing API.
 * See https://g.co/AppIndexing/AndroidStudio for more information.
 */


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

    etUsername = (EditText) findViewById(R.id.etUsername);
    etPassword = (EditText) findViewById(R.id.etPassword);
    tvRegisterLink = (TextView) findViewById(R.id.tvRegisterLink);
    bLogin = (Button) findViewById(R.id.bLogin);
    bLogin.setOnClickListener(this);
    userLocalStore = new UserLocalStore(this);
    tvRegisterLink.setOnClickListener(this);
    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
}

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this).setIcon(android.R.drawable.ic_dialog_alert).setTitle("Exit")
            .setMessage("Are you sure?")
            .setPositiveButton("yes", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Intent intent = new Intent(Intent.ACTION_MAIN);
                    intent.addCategory(Intent.CATEGORY_HOME);
                    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    startActivity(intent);
                    finish();
                }
            }).setNegativeButton("no", null).show();
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.bLogin:
if ((Login.this.etUsername.getText().toString().trim().length() > 0) && (Login.this.etPassword.getText().toString().trim().length() > 0)) {
                String username = etUsername.getText().toString();
                String password = etPassword.getText().toString();
                User user = new User(username, password);
                userLocalStore.storeUserData(user);

                Map obj = new LinkedHashMap();
                obj.put("id", user.username);
                obj.put("password", user.password);
                obj.put("type", "signin");
                obj.put("user.", "normal");

                Gson gson = new Gson();
                String json = gson.toJson(obj);
                System.out.println(json);
                Log.i("Ordered Json", json);
                ProgressDialog pd = new ProgressDialog(Login.this);
                pd.setMessage("loading");
                pd.show();
                MainActivity.mWebSocketClient.send(json);
//Here I want to use received Message from Server to Authenticate User.
                return;
            }
            Log.i("Login ERROR", "Username OR Password Missing");
            new AlertDialog.Builder(this).setIcon(android.R.drawable.ic_dialog_alert).setTitle("Error")
                    .setMessage("Email ID or Password Missing")
                    .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) { }
                    }).show();

            break;
        case R.id.tvRegisterLink:
            Toast.makeText(getApplicationContext(), "Register :)", Toast.LENGTH_SHORT).show();
            startActivity(new Intent(this, Register.class));
            break;
    }

}

修改

嗨，大家好，我只是通过Android Service，Singleton和Android Broadcast接收器的例子。我只是想到，如果我使用Android服务进行网络连接（Websocket）管理，数据传输和接收并使用Android Broadcast来通知特定的Activity有新的传入消息怎么办？

Answer 1

我认为使用Activities来处理服务器通信是错误的方法。当LoginActivity可见时，MainActivity在后台，并且系统可能会在套接字连接消失时随时将其终止。

这似乎是应该使用服务完成的任务的完美案例。实现所需的逻辑，如设置套接字以及在服务中发送和接收消息，并将其绑定到活动中的“onCreate”方法。一旦服务绑定，您就会询问服务用户是否已登录或请求登录用户。因为服务然后收到消息，您需要一种方法来报告活动。这可以通过广播或观察者来实现。对于后一种情况，您可能需要为Observer和Service创建和AIDL-Interface，这实际上并不那么难。

如果您不在应用程序中使用不同的进程，您可能只需创建一个Singleton而不是Service，并在不同的Activities中使用它。如果需要，您也可以稍后将Singleton放入服务中。

至于例子，除了default Service documentation

之外我什么也想不到

如何在Android中为所有活动使用单一方法？

1 个答案: