Java 客户端（安卓系统）&；服务器（本地主机控制台）通信问题

我不是一个经验丰富的Java和Android实践者，但是，我将尝试清楚地解释我的问题

对所需内容的非描述性解释：

package com.avineshwar.secureclient;

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;

public class MainActivity extends AppCompatActivity {
    private Socket client;
    private PrintWriter printwriter;
    private Button button;
    private TextView textView;
    private String messsage;

    SecureRandom random;
    KeyPairGenerator keyPairGenerator;
    KeyPair keyPair;
    PrivateKey privateKey;
    PublicKey publicKey;
    InputStreamReader inputStreamReader;
    BufferedReader bufferedReader = null;
    String server = null;

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

        button = (Button) findViewById(R.id.button1);
        textView = (TextView) findViewById(R.id.textView);


        // Button press event listener
        button.setOnClickListener(new View.OnClickListener() {

                                      public void onClick(View v) {
                                          random = new SecureRandom();
                                          keyPairGenerator = null;
                                          try {
                                              keyPairGenerator = KeyPairGenerator.getInstance("RSA");
                                          } catch (NoSuchAlgorithmException e) {
                                              e.printStackTrace();
                                          }
                                          keyPairGenerator.initialize(2048, random);
                                          keyPair = keyPairGenerator.generateKeyPair();
                                          privateKey = keyPair.getPrivate();
                                          publicKey = keyPair.getPublic();
                                          messsage = String.valueOf(publicKey);
                                          SendMessage sendMessageTask = new SendMessage();
                                          sendMessageTask.execute();
                                          if (server == null || server == "null") {
                                              server = "null";
                                              textView.setText(server);
                                          } else {
                                              textView.setText(server);
                                          }

                                      }
                                  }

        );
    }

    private class SendMessage extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... params) {
            try {

                try {
                    client = new Socket("192.168.1.169", 4444); // connect to the server
                } catch (IOException e) {
                    e.printStackTrace();
                }
                printwriter = null;
                printwriter = new PrintWriter(client.getOutputStream(), true);
                printwriter.write(messsage);

                inputStreamReader = null;
                inputStreamReader = new InputStreamReader(client.getInputStream());
                bufferedReader = new BufferedReader(inputStreamReader);
                server = bufferedReader.readLine();
                StringBuilder stringBuilder = new StringBuilder();
                while ((server = bufferedReader.readLine()) != null) {
                    stringBuilder.append(server + "\n");
                }
                server = stringBuilder.toString();
                client.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
    }

//@Override
//public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.slimple_text_client, menu);
//   return true;
// }
}

import com.sun.corba.se.impl.protocol.giopmsgheaders.Message;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import javax.crypto.KeyGenerator;
import javax.crypto.KeyGeneratorSpi;
import sun.nio.cs.Surrogate;

public class SecureServer {

    private static ServerSocket serverSocket;
    private static Socket clientSocket;
    private static InputStreamReader inputStreamReader;
    private static BufferedReader bufferedReader;
    private static String message;

    public static void main(String[] args) throws NoSuchAlgorithmException {

        SecureRandom random = new SecureRandom();
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048, random);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PrivateKey privateKey = keyPair.getPrivate();
        PublicKey publicKey = keyPair.getPublic();

        try {
            serverSocket = new ServerSocket(4444); // Server socket

        } catch (IOException e) {
            System.out.println("Could not listen on port: 4444");
        }

        System.out.println("Server started listening on the port 4444");

        while (true) {
            try {

                clientSocket = serverSocket.accept(); // accept the client connection
                inputStreamReader = null;
                inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
                bufferedReader = new BufferedReader(inputStreamReader); // get the client message
                message = bufferedReader.readLine();
                if (message == null || message == "null") {
                    message = "null";
                }
                System.out.println(message);
                PrintWriter out = null;
                out = new PrintWriter(clientSocket.getOutputStream(), true);
                message = publicKey.toString();
                out.write(message);
                System.out.println(message);
                out.close();
                clientSocket.close();
            } catch (IOException ex) {
                System.out.println("Problem in message reading");
            }
        }
    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Press to send RSA key"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/textView"
        android:layout_centerVertical="true"
        android:layout_alignParentStart="true" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.avineshwar.secureclient">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

客户端：Android应用程序，服务器：Localhost

客户机-->Server，即客户机向服务器发送某些内容

客户端服务器

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客户在出现异常时，请随时发布完整的stacktracethrown@VinceEmigh谢谢你的回复。没有这样的错误。那是我在玩弄代码，却不知道自己到底应该做什么。我确实有一个清晰的方法在我的脑海里我想做什么，然而，它需要粘在一起的方式是不清楚的。现在发生的事情是，当Telnet充当客户端时，通信似乎起作用，然而，当Android应用程序充当客户端时，情况并非如此。也许我怀疑的是，我做的事情在一次点击事件中是不可能的，或者我做错了。

inputStreamReader.close();

out = new PrintWriter(clientSocket.getOutputStream(), true);
message = publicKey.toString();
out.write(message);
System.out.println(message);