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
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.