Java基于Socket文件傳輸示例
最近需要進(jìn)行網(wǎng)絡(luò)傳輸大文件,于是對(duì)基于socket的文件傳輸作了一個(gè)初步的了解。在一位網(wǎng)友提供的程序基礎(chǔ)上,俺進(jìn)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(shù)據(jù)輸入/輸出輸出流進(jìn)行包裝,加快傳輸?shù)乃俣?。廢話少說,先來看服務(wù)器端的程序。
1.服務(wù)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(jìn)行傳輸?shù)奈募?/span>
String filePath = "D:\\lib.rar";
File fi = new File(filePath);

System.out.println("文件長(zhǎng)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(jìn)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(zhǎng)度傳給客戶端。這里要真正適用所有平臺(tái),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(xiàn)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(guān)閉socket鏈接哦,不然客戶端會(huì)等待server的數(shù)據(jù)過來,
// 直到socket超時(shí),導(dǎo)致數(shù)據(jù)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(chuàng)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(shè)置成服務(wù)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(wù)器成功!" + "\n");
return true;
 } catch (Exception e) {
System.out.print("連接服務(wù)器失敗!" + "\n");
return false;
}

}

 private void sendMessage() {
if (cs == null)
return;
 try {
cs.sendMessage(sendMessage);
 } catch (Exception e) {
System.out.print("發(fā)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(cuò)誤\n");
return;
}

 try {
//本地保存路徑,文件名會(huì)自動(dòng)從服務(wù)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(zhǎng)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(jìn)度條本為圖形界面的prograssBar做的,這里如果是打文件,可能會(huì)重復(fù)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(cuò)誤" + "\n");
return;
}
}

 public static void main(String arg[]) {
new ClientTest();
}
}
這就實(shí)現(xiàn)了從服務(wù)器端向客戶端發(fā)送文件的過程,當(dāng)然,反過來,也一樣.稍有不同.代碼中對(duì)跨平臺(tái)的細(xì)節(jié)沒有實(shí)現(xiàn),有時(shí)間或興趣的朋友可以提供一下.
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