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Android TCP 文件客户端与服务器DEMO介绍

运维开发网 https://www.qedev.com 2020-03-07 09:25 出处:网络 作者: 网络整理
主要功能是: 1、TCP服务器提供文件下载服务,服务器支持多线程。 2、TCP Client从服务器上下载指定的文件,Client也支持多线程。

主要功能是:

1、TCP服务器提供文件下载服务,服务器支持多线程。

2、TCP Client从服务器上下载指定的文件,Client也支持多线程。

首先是服务器,服务器是在PC机上,JAVA运行环境,主要参考网上的代码,自己做了支持多线程处理,代码如下:

复制代码 代码如下:

//file:DownloadServer.java

import java.net.*;

import java.io.*;

class ServerOneDownload extends Thread {

    private Socket socket = null;

    private String downloadRoot = null;

    private static final int Buffer = 8 * 1024;

    public ServerOneDownload(Socket socket, String downloadRoot) {

        super();

        this.socket = socket;

        this.downloadRoot = downloadRoot;

        start();

    }

    // 检查文件是否真实存在,核对下载密码,若文件不存在或密码错误,则返回-1,否则返回文件长度

    // 此处只要密码不为空就认为是正确的

    private long getFileLength(String fileName, String password) {

        // 若文件名或密码为null,则返回-1

        if ((fileName == null) || (password == null))

            return -1;

        // 若文件名或密码长度为0,则返回-1

        if ((fileName.length() == 0) || (password.length() == 0))

            return -1;

        String filePath = downloadRoot + fileName; // 生成完整文件路径

        System.out.println("DownloadServer getFileLength----->" + filePath);

        File file = new File(filePath);

        // 若文件不存在,则返回-1

        if (!file.exists())

            return -1;

        return file.length(); // 返回文件长度

    }

    // 用指定输出流发送指定文件

    private void sendFile(DataOutputStream out, String fileName)

            throws Exception {

        String filePath = downloadRoot + fileName; // 生成完整文件路径

        // 创建与该文件关联的文件输入流

        FileInputStream in = new FileInputStream(filePath);

        System.out.println("DownloadServer sendFile----->" + filePath);

        byte[] buf = new byte[Buffer];

        int len;

        // 反复读取该文件中的内容,直到读到的长度为-1

        while ((len = in.read(buf)) >= 0) {

            out.write(buf, 0, len); // 将读到的数据,按读到的长度写入输出流

            out.flush();

        }

        out.close();

        in.close();

    }

    // 提供下载服务

    public void download() throws IOException {

        System.out.println("启动下载... ");

        System.out.println("DownloadServer currentThread--->"

                + currentThread().getName());

        System.out.println("DownloadServer currentThread--->"

                + currentThread().getId());

        // 获取socket的输入流并包装成BufferedReader

        BufferedReader in = new BufferedReader(new InputStreamReader(

                socket.getInputStream()));

        // 获取socket的输出流并包装成DataOutputStream

        DataOutputStream out = new DataOutputStream(socket.getOutputStream());

        try {

            String parameterString = in.readLine(); // 接收下载请求参数

            // 下载请求参数字符串为自定义的格式,由下载文件相对于下载根目录的路径和

            // 下载密码组成,两者间以字符 "@ "分隔,此处按 "@ "分割下载请求参数字符串

            String[] parameter = parameterString.split("@ ");

            String fileName = parameter[0]; // 获取相对文件路径

            String password = parameter[1]; // 获取下载密码

            // 打印请求下载相关信息

            System.out.print(socket.getInetAddress().getHostAddress()

                    + "提出下载请求, ");

            System.out.println("请求下载文件: " + fileName);

            // 检查文件是否真实存在,核对下载密码,获取文件长度

            long len = getFileLength(fileName, password);

            System.out.println("download fileName----->" + fileName);

            System.out.println("download password----->" + password);

            out.writeLong(len); // 向客户端返回文件大小

            out.flush();

            // 若获取的文件长度大于等于0,则允许下载,否则拒绝下载

            if (len >= 0) {

                System.out.println("允许下载 ");

                System.out.println("正在下载文件 " + fileName + "... ");

                sendFile(out, fileName); // 向客户端发送文件

                System.out.println(fileName +": "+"下载完毕 ");

            } else {

                System.out.println("下载文件不存在或密码错误,拒绝下载! ");

            }

        } catch (Exception e) {

            System.out.println(e.toString());

        } finally {

            socket.close(); // 关闭socket

        }

    }

    @Override

    public void run() {

        try {

            download();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        // TODO Auto-generated method stub

        super.run();

    }

}

public class DownloadServer {

    private final static int port = 65525;

    private static String root = "C:// "; // 下载根目录

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

        String temp = null;

        // 监听端口

        try {

            // 包装标准输入为BufferedReader

            BufferedReader systemIn = new BufferedReader(new InputStreamReader(

                    System.in));

            while (true) {

                System.out.print("请输入下载服务器的下载根目录: ");

                root = systemIn.readLine().trim(); // 从标准输入读取下载根目录

                File file = new File(root);

                // 若该目录确实存在且为目录,则跳出循环

                if ((file.exists()) && (file.isDirectory())) {

                    temp = root.substring(root.length() - 1, root.length());

                    if (!temp.equals("//"))

                        root += "//";

                }

                break;

            }

        } catch (Exception e) {

            System.out.println(e.toString());

        }

        ServerSocket serverSocket = new ServerSocket(port);

        System.out.println("Server start...");

        try {

            while (true) {

                Socket socket = serverSocket.accept();

                new ServerOneDownload(socket, root);

            }

        } finally {

            serverSocket.close();

        }

    }

}

File Download Client

Client输入IP和文件名即可直接从服务器上下载,还是看代码。

复制代码 代码如下:

//file:DownLoadClient.java

package org.piaozhiye.study;

import java.io.IOException;

import java.net.Socket;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

public class DownLoadClient extends Activity {

    private Button download = null;

    private EditText et_serverIP = null;

    private EditText et_fileName= null;

    private String downloadFile = null;

    private final static int PORT = 65525;

    private final static String defaultIP = "192.168.0.100";

    private static String serverIP = null;

    private Socket socket;

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        download = (Button)findViewById(R.id.download);

        et_serverIP= (EditText)findViewById(R.id.et_serverip);

        et_fileName = (EditText)findViewById(R.id.et_filename);

        et_serverIP.setText("192.168.0.100");

      download.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                 serverIP = et_serverIP.getText().toString();

                 if(serverIP == null){

                     serverIP = defaultIP;

                 }

                 System.out.println("DownLoadClient serverIP--->" + serverIP );

                    System.out.println("DownLoadClient MainThread--->" + Thread.currentThread().getId() );

                try{

                    socket = new Socket(serverIP, PORT);

                }catch(IOException e){

                }

                 downloadFile = et_fileName.getText().toString();

            Thread downFileThread = new Thread(new DownFileThread(socket, downloadFile));

            downFileThread.start();

                System.out.println("DownLoadClient downloadFile--->" + downloadFile );

            }

        });

    }

}

file:DownFileThread.java

复制代码 代码如下:

package org.piaozhiye.study;

import java.io.BufferedInputStream;

import java.io.DataInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

import java.net.Socket;

public class DownFileThread extends Thread {

    private Socket socket;

    private String downloadFile;

    private final static int Buffer = 8 * 1024;

    public DownFileThread(Socket socket, String downloadFile) {

        super();

        this.socket = socket;

        this.downloadFile = downloadFile;

    }

    public Socket getSocket() {

        return socket;

    }

    public void setSocket(Socket socket) {

        this.socket = socket;

    }

    public String getDownloadFile() {

        return downloadFile;

    }

    public void setDownloadFile(String downloadFile) {

        this.downloadFile = downloadFile;

    }

    // 向服务器提出下载请求,返回下载文件的大小

    private long request(String fileName, String password) throws IOException {

        // 获取socket的输入流并包装成DataInputStream

        DataInputStream in = new DataInputStream(socket.getInputStream());

        // 获取socket的输出流并包装成PrintWriter

        PrintWriter out = new PrintWriter(new OutputStreamWriter(

                socket.getOutputStream()));

        // 生成下载请求字符串

        String requestString = fileName + "@ " + password;

        out.println(requestString); // 发出下载请求

        out.flush();

        return in.readLong(); // 接收并返回下载文件长度

    }

    // 接收并保存文件

    private void receiveFile(String localFile) throws Exception {

        // 获取socket的输入流并包装成BufferedInputStream

        BufferedInputStream in = new BufferedInputStream(

                socket.getInputStream());

        // 获取与指定本地文件关联的文件输出流

        FileOutputStream out = new FileOutputStream(localFile);

        byte[] buf = new byte[Buffer];

        int len;

        // 反复读取该文件中的内容,直到读到的长度为-1

        while ((len = in.read(buf)) >= 0) {

            out.write(buf, 0, len); // 将读到的数据,按读到的长度写入输出流

            out.flush();

        }

        out.close();

        in.close();

    }

    // 从服务器下载文件

    public void download(String downloadFile) throws Exception {

        try {

            String password = "password";

            // String downloadFile ="imissyou.mp3";

            String localpath = "/sdcard/";

            String localFile = localpath + downloadFile;

            long fileLength = request(downloadFile, password);

            // 若获取的文件长度大于等于0,说明允许下载,否则说明拒绝下载

            if (fileLength >= 0) {

                System.out.println("fileLength: " + fileLength + " B");

                System.out.println("downing...");

                receiveFile(localFile); // 从服务器接收文件并保存至本地文件

                System.out.println("file:" + downloadFile + " had save to "

                        + localFile);

            } else {

                System.out.println("download " + downloadFile + " error! ");

            }

        } catch (IOException e) {

            System.out.println(e.toString());

        } finally {

            socket.close(); // 关闭socket

        }

    }

    @Override

    public void run() {

        System.out.println("DownFileThread currentThread--->"

                + DownFileThread.currentThread().getId());

        // TODO Auto-generated method stub

        try {

            download(downloadFile);

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        super.run();

    }

}

layout.xml

复制代码 代码如下:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    >

<TextView

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:paddingLeft="10dp"

    android:paddingRight="10dp"

    android:paddingTop="5dp"

    android:paddingBottom="5dp"

    android:text="服务器IP:"

    />

    <EditText

    android:id="@+id/et_serverip"

    android:layout_width="fill_parent"

    android:layout_height="wrap_content"

    android:paddingLeft="10dp"

    android:paddingRight="10dp"

    android:paddingTop="5dp"

    android:paddingBottom="5dp"

    />

    <TextView

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:paddingLeft="10dp"

    android:paddingRight="10dp"

    android:paddingTop="5dp"

    android:paddingBottom="5dp"

    android:text="下载文件名:"

    />

    <EditText

    android:id="@+id/et_filename"

    android:layout_width="fill_parent"

    android:layout_height="wrap_content"

    android:paddingLeft="10dp"

    android:paddingRight="10dp"

    android:paddingTop="5dp"

    android:paddingBottom="5dp"

    />

    <Button

    android:id="@+id/download"

    android:layout_width="fill_parent"

    android:layout_height="wrap_content"

    android:text="download"

    />

</LinearLayout>

同时别忘了权限:

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

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