Posted on 2007-10-13 09:11
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Socket
Java基于Socket文件傳輸示例
最近需要進行網絡傳輸大文件，于是對基于socket的文件傳輸作了一個初步的了解。在一位網友提供的程序基礎上，俺進行了一些加工，采用了緩沖輸入/輸出流來包裝輸出流，再采用數據輸入/輸出輸出流進行包裝，加快傳輸的速度。廢話少說，先來看服務器端的程序。
1.服務器端
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) {
// 選擇進行傳輸的文件
String filePath = "D:\\lib.rar";
File fi = new File(filePath);
System.out.println("文件長度:" + (int) fi.length());
// public Socket accept() throws
// IOException偵聽并接受到此套接字的連接。此方法在進行連接之前一直阻塞。
s = ss.accept();
System.out.println("建立socket鏈接");
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());
//將文件名及長度傳給客戶端。這里要真正適用所有平臺，例如中文名的處理，還需要加工，具體可以參見Think In Java 4th里有現成的代碼。
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();
// 注意關閉socket鏈接哦，不然客戶端會等待server的數據過來，
// 直到socket超時，導致數據不完整。
fis.close();
s.close();
System.out.println("文件傳輸完成");
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String arg[]) {
new ServerTest().start();
}
}
2.socket的Util輔助類
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;
}
/** *//**
* 創建socket連接
*
* @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.客戶端
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";// 設置成服務器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("連接服務器成功!" + "\n");
return true;
} catch (Exception e) {
System.out.print("連接服務器失敗!" + "\n");
return false;
}
}
private void sendMessage() {
if (cs == null)
return;
try {
cs.sendMessage(sendMessage);
} catch (Exception e) {
System.out.print("發送消息失敗!" + "\n");
}
}
private void getMessage() {
if (cs == null)
return;
DataInputStream inputStream = null;
try {
inputStream = cs.getMessageStream();
} catch (Exception e) {
System.out.print("接收消息緩存錯誤\n");
return;
}
try {
//本地保存路徑，文件名會自動從服務器端繼承而來。
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("文件的長度為:" + len + "\n");
System.out.println("開始接收文件!" + "\n");
while (true) {
int read = 0;
if (inputStream != null) {
read = inputStream.read(buf);
}
passedlen += read;
if (read == -1) {
break;
}
//下面進度條本為圖形界面的prograssBar做的，這里如果是打文件，可能會重復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，文件存為" + savePath + "\n");
fileOut.close();
} catch (Exception e) {
System.out.println("接收消息錯誤" + "\n");
return;
}
}
public static void main(String arg[]) {
new ClientTest();
}
}
這就實現了從服務器端向客戶端發送文件的過程,當然,反過來,也一樣.稍有不同.代碼中對跨平臺的細節沒有實現,有時間或興趣的朋友可以提供一下.