javasocket文件上傳

1. 基於java Socket實現文件傳輸

如果使用TCP套接字，關鍵是協議設計的問題，需要區別網路數據流中各部分的含義，如果使用UDP套接字，還是協議設計的問題，但是太有挑戰性了，建議不要嘗試。

2. Java socket上傳文件，伺服器的文件比上傳的多了一行（最後一行）。不知道怎麼處理（代碼如下）

inti=0;
while((line=clientIn.readLine())!=null){
if(i++!=0)
bw.newLine();
bw.write(line);
bw.flush();
}

3. java使用socket文件上傳

for(int size=0;size!=-1;size=fis.read(buf)){
output.write(buf,0,size);
output.flush();
}
for(int size=0;size!=-1;size=fis.read(buf))
在buf中讀取位元組;當buf沒有內容了,返回的-1;在這個之前,一直在循環;
output.write(buf,0,size);
output.flush();
把buf中道0開始到size個位元組的內容寫入輸出流緩沖中
並用 flush()確認發送到輸出流中了;
我的意見是output.write(buf,0,size);
改為output.write(buf);
你接受數據部分代碼怎麼寫的,是不是size等於一個大於1024的整數了而出錯

4. 關於用JAVA的SOCKET傳輸文件

點對點傳輸文件
/*
import java.io.*;
import java.net.*;
import java.util.*;
*/
private HttpURLConnection connection;//存儲連接
private int downsize = -1;//下載文件大小,初始值為-1
private int downed = 0;//文加已下載大小,初始值為0
private RandomAccessFile savefile;//記錄下載信息存儲文件
private URL fileurl;//記錄要下載文件的地址
private DataInputStream fileStream;//記錄下載的數據流
try{
/*開始創建下載的存儲文件,並初始化值*/
File tempfileobject = new File("h:\\webwork-2.1.7.zip");
if(!tempfileobject.exists()){
/*文件不存在則建立*/
tempfileobject.createNewFile();
}
savefile = new RandomAccessFile(tempfileobject,"rw");

/*建立連接*/
fileurl = new URL("https://webwork.dev.java.net/files/documents/693/9723/webwork-2.1.7.zip");
connection = (HttpURLConnection)fileurl.openConnection();
connection.setRequestProperty("Range","byte="+this.downed+"-");

this.downsize = connection.getContentLength();
//System.out.println(connection.getContentLength());

new Thread(this).start();
}
catch(Exception e){
System.out.println(e.toString());
System.out.println("構建器錯誤");
System.exit(0);
}
public void run(){
/*開始下載文件,以下測試非斷點續傳,下載的文件存在問題*/
try{
System.out.println("begin!");
Date begintime = new Date();
begintime.setTime(new Date().getTime());
byte[] filebyte;
int onecelen;
//System.out.println(this.connection.getInputStream().getClass().getName());
this.fileStream = new DataInputStream(
new BufferedInputStream(
this.connection.getInputStream()));
System.out.println("size = " + this.downsize);
while(this.downsize != this.downed){
if(this.downsize - this.downed > 262144){//設置為最大256KB的緩存
filebyte = new byte[262144];
onecelen = 262144;
}
else{
filebyte = new byte[this.downsize - this.downed];
onecelen = this.downsize - this.downed;
}
onecelen = this.fileStream.read(filebyte,0,onecelen);
this.savefile.write(filebyte,0,onecelen);
this.downed += onecelen;
System.out.println(this.downed);
}
this.savefile.close();
System.out.println("end!");
System.out.println(begintime.getTime());
System.out.println(new Date().getTime());
System.out.println(begintime.getTime() - new Date().getTime());
}
catch(Exception e){
System.out.println(e.toString());
System.out.println("run()方法有問題!");
}
}

/***
//FileClient.java
import java.io.*;
import java.net.*;
public class FileClient {
public static void main(String[] args) throws Exception {

//使用本地文件系統接受網路數據並存為新文件

File file = new File("d:\\fmd.doc");

file.createNewFile();

RandomAccessFile raf = new RandomAccessFile(file, "rw");

// 通過Socket連接文件伺服器

Socket server = new Socket(InetAddress.getLocalHost(), 3318);
//創建網路接受流接受伺服器文件數據
InputStream netIn = server.getInputStream();
InputStream in = new DataInputStream(new BufferedInputStream(netIn));
//創建緩沖區緩沖網路數據

byte[] buf = new byte[2048];

int num = in.read(buf);

while (num != (-1)) {//是否讀完所有數據

raf.write(buf, 0, num);//將數據寫往文件

raf.skipBytes(num);//順序寫文件位元組

num = in.read(buf);//繼續從網路中讀取文件

}
in.close();
raf.close();
}
}

//FileServer.java
import java.io.*;
import java.util.*;
import java.net.*;
public class FileServer {
public static void main(String[] args) throws Exception {

//創建文件流用來讀取文件中的數據

File file = new File("d:\\系統特點.doc");

FileInputStream fos = new FileInputStream(file);

//創建網路伺服器接受客戶請求

ServerSocket ss = new ServerSocket(8801);

Socket client = ss.accept();

//創建網路輸出流並提供數據包裝器

OutputStream netOut = client.getOutputStream();

OutputStream doc = new DataOutputStream(
new BufferedOutputStream(netOut));

//創建文件讀取緩沖區

byte[] buf = new byte[2048];

int num = fos.read(buf);
while (num != (-1)) {//是否讀完文件
doc.write(buf, 0, num);//把文件數據寫出網路緩沖區
doc.flush();//刷新緩沖區把數據寫往客戶端
num = fos.read(buf);//繼續從文件中讀取數據
}
fos.close();
doc.close();
}
}
*/

5. 怎麼用java的socket進行文件傳輸誰能給個簡單的例子，包括發送端和接收端。

java中的網路信息傳輸方式是基於TCP協議或者UD協議P的,socket是基於TCP協議的

例子1
（1）客戶端程序：
import java.io.*;
import java.net.*;
public class Client
{ public static void main(String args[])
{ String s=null;
Socket mysocket;
DataInputStream in=null;
DataOutputStream out=null;
try{
mysocket=new Socket("localhost",4331);
in=new DataInputStream(mysocket.getInputStream());
out=new DataOutputStream(mysocket.getOutputStream());
out.writeUTF("你好！");//通過 out向"線路"寫入信息。
while(true)
{
s=in.readUTF();//通過使用in讀取伺服器放入"線路"里的信息。堵塞狀態，
//除非讀取到信息。
out.writeUTF(":"+Math.random());
System.out.println("客戶收到:"+s);
Thread.sleep(500);
}
}
catch(IOException e)
{ System.out.println("無法連接");
}
catch(InterruptedException e){}
}
}
（2）伺服器端程序：
import java.io.*;import java.net.*;
public class Server
{ public static void main(String args[])
{ ServerSocket server=null;
Socket you=null;String s=null;
DataOutputStream out=null;DataInputStream in=null;
try{ server=new ServerSocket(4331);}
catch(IOException e1){System.out.println("ERRO:"+e1);}
try{ you=server.accept();
in=new DataInputStream(you.getInputStream());
out=new DataOutputStream(you.getOutputStream());
while(true)
{
s=in.readUTF();// 通過使用in讀取客戶放入"線路"里的信息。堵塞狀態，
//除非讀取到信息。

out.writeUTF("你好:我是伺服器");//通過 out向"線路"寫入信息.
out.writeUTF("你說的數是:"+s);
System.out.println("伺服器收到:"+s);
Thread.sleep(500);
}
}
catch(IOException e)
{ System.out.println(""+e);
}
catch(InterruptedException e){}
}
}

例子(2)
(1) 客戶端
import java.net.*;import java.io.*;
import java.awt.*;import java.awt.event.*;
import java.applet.*;
public class Computer_client extends Applet implements Runnable,ActionListener
{ Button 計算;TextField 輸入三邊長度文本框,計算結果文本框;
Socket socket=null;
DataInputStream in=null; DataOutputStream out=null;
Thread thread;
public void init()
{ setLayout(new GridLayout(2,2));
Panel p1=new Panel(),p2=new Panel();
計算=new Button(" 計算");
輸入三邊長度文本框=new TextField(12);計算結果文本框=new TextField(12);
p1.add(new Label("輸入三角形三邊的長度,用逗號或空格分隔:"));
p1.add( 輸入三邊長度文本框);
p2.add(new Label("計算結果："));p2.add(計算結果文本框);p2.add(計算);
計算.addActionListener(this);
add(p1);add(p2);
}
public void start()
{ try
{ //和小程序所駐留的伺服器建立套接字連接：
socket = new Socket(this.getCodeBase().getHost(), 4331);
in =new DataInputStream(socket.getInputStream());
out = new DataOutputStream(socket.getOutputStream());
}
catch (IOException e){}
if(thread == null)
{ thread = new Thread(this);
thread.start();
}
}
public void run()
{ String s=null;
while(true)
{ try{ s=in.readUTF();//堵塞狀態，除非讀取到信息。

計算結果文本框.setText(s);
}
catch(IOException e)
{ 計算結果文本框.setText("與伺服器已斷開");
break;
}
}
}
public void actionPerformed(ActionEvent e)
{ if(e.getSource()==計算)
{ String s=輸入三邊長度文本框.getText();
if(s!=null)
{ try { out.writeUTF(s);
}
catch(IOException e1){}
}
}
}
}

(2) 伺服器端
import java.io.*;import java.net.*;
import java.util.*;import java.sql.*;
public class Computer_server
{ public static void main(String args[])
{ ServerSocket server=null;Server_thread thread;
Socket you=null;
while(true)
{ try{ server=new ServerSocket(4331);
}
catch(IOException e1)
{ System.out.println("正在監聽"); //ServerSocket對象不能重復創建。
}
try{ you=server.accept();
System.out.println("客戶的地址:"+you.getInetAddress());
}
catch (IOException e)
{ System.out.println("正在等待客戶");
}
if(you!=null)
{ new Server_thread(you).start(); //為每個客戶啟動一個專門的線程。
}
else
{ continue;
}
}
}
}
class Server_thread extends Thread
{ Socket socket;Connection Con=null;Statement Stmt=null;
DataOutputStream out=null;DataInputStream in=null;int n=0;
String s=null;
Server_thread(Socket t)
{ socket=t;
try { in=new DataInputStream(socket.getInputStream());
out=new DataOutputStream(socket.getOutputStream());
}
catch (IOException e)
{}
}
public void run()
{ while(true)
{ double a[]=new double[3] ;int i=0;
try{ s=in.readUTF();堵塞狀態，除非讀取到信息。

StringTokenizer fenxi=new StringTokenizer(s," ,");
while(fenxi.hasMoreTokens())
{ String temp=fenxi.nextToken();
try{ a[i]=Double.valueOf(temp).doubleValue();i++;
}
catch(NumberFormatException e)
{ out.writeUTF("請輸入數字字元");
}
}
double p=(a[0]+a[1]+a[2])/2.0;
out.writeUTF(" "+Math.sqrt(p*(p-a[0])*(p-a[1])*(p-a[2])));
sleep(2);
}
catch(InterruptedException e){}
catch (IOException e)
{ System.out.println("客戶離開");
break;
}
}
}
}

這些例子都是Java2實用教程上的.

6. 用java socket實現一個伺服器對多個客戶端的文件傳輸

通過socket可以用如下方式進行。
1.啟動服務端代碼。
2.啟動客戶端自動連接服務端。
3.服務端上傳文件，保存文件和路徑。
4.將路徑發送給連接服務端的客戶端。

7. 利用java socket實現文件傳輸

1.伺服器端

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偵聽並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台，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";// 設置成伺服器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("連接伺服器成功!" + "\n");
return true;
} catch (Exception e) {
System.out.print("連接伺服器失敗!" + "\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，文件名會自動從伺服器端繼承而來。
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，可能會重復列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();
}
}