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Java基于Socket文件传输示例(转)

最近需要进行网络传输大文件,于是对基于socket的文件传输作了一个初步的了解。在一位网友提供的程序基础上,俺进行了一些加工,采用了缓冲输入/输出流来包装输出流,再采用数据输入/输出输出流进行包装,加快传输的速度。废话少说,先来看服务器端的程序。

1.服务器端

package sterning;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerTest {
    int port = 8821;

    void start() {
        Socket s = null;
        try {
            ServerSocket ss = new ServerSocket(port);
            while (true{
                // 选择进行传输的文件
                String filePath = "D:\\lib.rar";
                File fi = new File(filePath);

                System.out.println("文件长度:" + (int) fi.length());

                // public Socket accept() throws
                // IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。

                s = ss.accept();
                System.out.println("建立socket链接");
                DataInputStream dis = new DataInputStream(new BufferedInputStream(s.getInputStream()));
                dis.readByte();

                DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));
                DataOutputStream ps = new DataOutputStream(s.getOutputStream());
                //将文件名及长度传给客户端。这里要真正适用所有平台,例如中文名的处理,还需要加工,具体可以参见Think In Java 4th里有现成的代码。
                ps.writeUTF(fi.getName());
                ps.flush();
                ps.writeLong((long) fi.length());
                ps.flush();

                int bufferSize = 8192;
                byte[] buf = new byte[bufferSize];

                while (true{
                    int read = 0;
                    if (fis != null{
                        read = fis.read(buf);
                    }

                    if (read == -1{
                        break;
                    }
                    ps.write(buf, 0, read);
                }
                ps.flush();
                // 注意关闭socket链接哦,不然客户端会等待server的数据过来,
                // 直到socket超时,导致数据不完整。                
                fis.close();
                s.close();                
                System.out.println("文件传输完成");
            }

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

    public static void main(String arg[]) {
        new ServerTest().start();
    }
}


2.socket的Util辅助类

package sterning;import java.net.*;import java.io.*;public class ClientSocket {    private String ip;    private int port;    private Socket socket = null;    DataOutputStream out = null;    DataInputStream getMessageStream = null;    public ClientSocket(String ip, int port) {        this.ip = ip;        this.port = port;    }    /**     * 创建socket连接     *      * @throws Exception     *             exception     */    public void CreateConnection() throws Exception {        try {            socket = new Socket(ip, port);        } catch (Exception e) {            e.printStackTrace();            if (socket != null)                socket.close();            throw e;        } finally {        }    }    public void sendMessage(String sendMessage) throws Exception {        try {            out = new DataOutputStream(socket.getOutputStream());            if (sendMessage.equals("Windows")) {                out.writeByte(0x1);                out.flush();                return;            }            if (sendMessage.equals("Unix")) {                out.writeByte(0x2);                out.flush();                return;            }            if (sendMessage.equals("Linux")) {                out.writeByte(0x3);                out.flush();            } else {                out.writeUTF(sendMessage);                out.flush();            }        } catch (Exception e) {            e.printStackTrace();            if (out != null)                out.close();            throw e;        } finally {        }    }    public DataInputStream getMessageStream() throws Exception {        try {            getMessageStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));            return getMessageStream;        } catch (Exception e) {            e.printStackTrace();            if (getMessageStream != null)                getMessageStream.close();            throw e;        } finally {        }    }    public void shutDownConnection() {        try {            if (out != null)                out.close();            if (getMessageStream != null)                getMessageStream.close();            if (socket != null)                socket.close();        } catch (Exception e) {        }    }}

 

3.客户端

package sterning;import java.io.BufferedOutputStream;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.FileOutputStream;public class ClientTest {    private ClientSocket cs = null;    private String ip = "localhost";// 设置成服务器IP    private int port = 8821;    private String sendMessage = "Windwos";    public ClientTest() {        try {            if (createConnection()) {                sendMessage();                getMessage();            }        } catch (Exception ex) {            ex.printStackTrace();        }    }    private boolean createConnection() {        cs = new ClientSocket(ip, port);        try {            cs.CreateConnection();            System.out.print("连接服务器成功!" + "\n");            return true;        } catch (Exception e) {            System.out.print("连接服务器失败!" + "\n");            return false;        }    }    private void sendMessage() {        if (cs == null)            return;        try {            cs.sendMessage(sendMessage);        } catch (Exception e) {            System.out.print("发送消息失败!" + "\n");        }    }    private void getMessage() {        if (cs == null)            return;        DataInputStream inputStream = null;        try {            inputStream = cs.getMessageStream();        } catch (Exception e) {            System.out.print("接收消息缓存错误\n");            return;        }        try {            //本地保存路径,文件名会自动从服务器端继承而来。            String savePath = "E:\\";            int bufferSize = 8192;            byte[] buf = new byte[bufferSize];            int passedlen = 0;            long len=0;                        savePath += inputStream.readUTF();            DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new BufferedOutputStream(new FileOutputStream(savePath))));            len = inputStream.readLong();                        System.out.println("文件的长度为:" + len + "\n");            System.out.println("开始接收文件!" + "\n");                                while (true) {                int read = 0;                if (inputStream != null) {                    read = inputStream.read(buf);                }                passedlen += read;                if (read == -1) {                    break;                }                //下面进度条本为图形界面的prograssBar做的,这里如果是打文件,可能会重复打印出一些相同的百分比                System.out.println("文件接收了" +  (passedlen * 100/ len) + "%\n");                fileOut.write(buf, 0, read);            }            System.out.println("接收完成,文件存为" + savePath + "\n");            fileOut.close();        } catch (Exception e) {            System.out.println("接收消息错误" + "\n");            return;        }    }    public static void main(String arg[]) {        new ClientTest();    }}

 


这就实现了从服务器端向客户端发送文件的过程,当然,反过来,也一样.稍有不同.代码中对跨平台的细节没有实现,有时间或兴趣的朋友可以提供一下.

Java基于Socket文件传输示例(转)