Java基于Socket实现文件传输示例

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(); 
}
}

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) {

}
}
}

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(); 
}
}