Android客户端和Java服务器TCP通信(Android client and Java se

2019-07-28 21:37发布

我开发一个Android应用程序(客户端),并希望它使用TCP通信我的Java服务器连接。

我已经做了代码 - 简单的程序,客户端发送邮件和服务器回声回 - 如下:

服务器代码:

    import java.net.*;


public class Server {

    public static void main(String[] args) {

        int nreq = 1;
        try
        {
            ServerSocket sock = new ServerSocket (8080);
            for (;;)
            {
                Socket newsock = sock.accept();
                System.out.println("Creating thread ...");
                Thread t = new ThreadHandler(newsock,nreq);
                t.start();
            }
        }
        catch (Exception e)
        {
            System.out.println("IO error " + e);
        }
        System.out.println("End!");
    }
}

在服务器的同一个项目文件中的线程处理程序的代码:

    import java.io.*;
import java.net.*;

class ThreadHandler extends Thread {
    Socket newsock;
    int n;

    ThreadHandler(Socket s, int v) {
        newsock = s;
        n = v;
    }


    public void run() {
        try {

            PrintWriter outp = new PrintWriter(newsock.getOutputStream(), true);
            BufferedReader inp = new BufferedReader(new InputStreamReader(
                    newsock.getInputStream()));

            outp.println("Hello :: enter QUIT to exit \n");
            boolean more_data = true;
            String line;

            while (more_data) {
                line = inp.readLine();
                System.out.println("Message '" + line + "' echoed back to client.");
                if (line == null) {
                    System.out.println("line = null");
                    more_data = false;
                } else {
                    outp.println("From server: " + line + ". \n");
                    if (line.trim().equals("QUIT"))
                        more_data = false;
                }
            }
            newsock.close();
            System.out.println("Disconnected from client number: " + n);
        } catch (Exception e) {
            System.out.println("IO error " + e);
        }

    }
}

这是客户端(安卓):

package com.android.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class Client extends Activity {
    /** Called when the activity is first created. */
    Scanner scanner = new Scanner(System.in);

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

        final EditText msg = (EditText) findViewById(R.id.etMsg);
        Button send = (Button) findViewById(R.id.bSend);
        final TextView convo = (TextView) findViewById(R.id.tvConvo);
        final TextView status = (TextView) findViewById(R.id.tvStatus);

        try {
            send.setOnClickListener(new View.OnClickListener() {

                Socket s = new Socket("localhost", 8080);
                String message = msg.getText().toString();

                @Override
                public void onClick(View v) {
                    status.setText("...");
                    PrintWriter outp = null;
                    BufferedReader inp = null;
                    status.setText("Established connection..");
                    String serverMsg = null;

                    try {
                        outp = new PrintWriter(s.getOutputStream(), true);
                        inp = new BufferedReader(new InputStreamReader(s.getInputStream()));
                        serverMsg = inp.readLine();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    convo.append(serverMsg + "\n");

                    if (message != null) {
                        if (msg.getText().toString().trim() == "QUIT") {
                            try {
                                s.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                            status.setText("Disconnected from server.");

                        } else {
                                try {

                                    convo.append(message + "\n");
                                    outp.println(message); 
                                    serverMsg = inp.readLine();
                                    convo.append(serverMsg + "\n");
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                        }

                    }
                    else
                        status.setText("Problem in connection..!");
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这是XML文件:

<?xml version="1.0" encoding="utf-8" ?> 
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical">
  <TextView android:id="@+id/tvText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Your message here:" /> 
- <EditText android:id="@+id/etMsg" android:layout_width="match_parent" android:layout_height="wrap_content" android:ems="10">
  <requestFocus /> 
  </EditText>
  <TextView android:id="@+id/tvStatus" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Status..." android:textAppearance="?android:attr/textAppearanceSmall" /> 
  <Button android:id="@+id/bSend" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Send" /> 
  <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Conversation:" android:textAppearance="?android:attr/textAppearanceLarge" /> 
  <TextView android:id="@+id/tvConvo" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="" /> 
  </LinearLayout>

我试图运行它,但没有任何反应。 当我点击按钮的TextView不查看来自服务器的“你好”消息。

Answer 1:

你与你的Android客户端连接localhost

Socket s = new Socket("localhost", 8080);

这将只有当你的服务器运行在Android设备上运行的工作。 但我认为这是您的PC上运行。 所以,当你运行你的Android模拟器的应用程序,你可以连接到10.0.2.2 ,以便联系主机。 在真实设备上,你必须找出哪些可以通过Android设备,例如通过Wi-Fi来达到您的服务器的IP地址。



Answer 2:

如果您的服务器是在Windows上,键入cmd在开始菜单的搜索框,然后输入ipconfig命令提示符。 你会看到类似IVP4 Address----- 192.168.0.101 。 您需要在客户端上使用此地址和端口号。



文章来源: Android client and Java server TCP communication