[英]Java multiple file transfer over socket
好的,嘗試通過套接字傳輸指定的文件目錄,從數組列表中刪除目錄對象,因此只剩下文件,並通過同一個套接字 1 個 1 傳輸它們。 這里的arraylist 只填充了文件,沒有目錄。 這里分別是客戶端和服務器的接收和發送代碼。 代碼運行良好,沒有錯誤,除了所有數據都被寫入第一個文件。 后續文件在服務器文件夾中創建,但它們是 0 字節。 任何投入將不勝感激。
這是接收文件的服務器代碼
public void receive(){
try {
DataInputStream dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
//read the number of files from the client
int number = dis.readInt();
ArrayList<File>files = new ArrayList<File>(number);
System.out.println("Number of Files to be received: " +number);
//read file names, add files to arraylist
for(int i = 0; i< number;i++){
File file = new File(dis.readUTF());
files.add(file);
}
int n = 0;
byte[]buf = new byte[4092];
//outer loop, executes one for each file
for(int i = 0; i < files.size();i++){
System.out.println("Receiving file: " + files.get(i).getName());
//create a new fileoutputstream for each new file
FileOutputStream fos = new FileOutputStream("C:\\users\\tom5\\desktop\\salestools\\" +files.get(i).getName());
//read file
while((n = dis.read(buf)) != -1){
fos.write(buf,0,n);
fos.flush();
}
fos.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
這是發送文件的客戶端代碼
public void send(ArrayList<File>files){
try {
DataInputStream dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
System.out.println(files.size());
//write the number of files to the server
dos.writeInt(files.size());
dos.flush();
//write file names
for(int i = 0 ; i < files.size();i++){
dos.writeUTF(files.get(i).getName());
dos.flush();
}
//buffer for file writing, to declare inside or outside loop?
int n = 0;
byte[]buf = new byte[4092];
//outer loop, executes one for each file
for(int i =0; i < files.size(); i++){
System.out.println(files.get(i).getName());
//create new fileinputstream for each file
FileInputStream fis = new FileInputStream(files.get(i));
//write file to dos
while((n =fis.read(buf)) != -1){
dos.write(buf,0,n);
dos.flush();
}
//should i close the dataoutputstream here and make a new one each time?
}
//or is this good?
dos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
您正在讀取套接字,直到read()
返回 -1。 這是流結束條件 (EOS)。 EOS 在對等方關閉連接時發生。 不是當它完成寫入一個文件時。
您需要在每個文件之前發送文件大小。 您已經對文件計數做了類似的事情。 然后確保您為該文件讀取了那么多字節:
String filename = dis.readUTF();
long fileSize = dis.readLong();
FileOutputStream fos = new FileOutputStream(filename);
while (fileSize > 0 && (n = dis.read(buf, 0, (int)Math.min(buf.length, fileSize))) != -1)
{
fos.write(buf,0,n);
fileSize -= n;
}
fos.close();
您可以將所有這些都包含在一個循環中,該循環在readUTF()
拋出EOFException
時終止。 相反,在發送數據之前,您當然必須在發送方調用writeUTF(filename)
和writeLong(filesize)
。
我是這樣做的,它工作得很好,你可以看看:
發送
byte[] done = new byte[3];
String str = "done"; //randomly anything
done = str.getBytes();
for (int i = 0; i < files.size(); i++) {
System.out.println(files.get(i).getName());
FileInputStream fis = new FileInputStream(files.get(i));
while ((n = fis.read(buf)) != -1) {
dos.write(buf, 0, n);
System.out.println(n);
dos.flush();
}
//should i close the dataoutputstream here and make a new one each time?
dos.write(done, 0, 3);
dos.flush();
}
//or is this good?
dos.close();
收到
for (int i = 0; i < files.size(); i++) {
System.out.println("Receiving file: " + files.get(i).getName());
//create a new fileoutputstream for each new file
fos = new FileOutputStream("C:\\users\\tom5\\desktop\\salestools\\" + files.get(i).getName());
//read file
while ((n = dis.read(buf)) != -1 && n != 3) {
fos.write(buf, 0, n);
fos.flush();
}
fos.close();
}
我已經創建了一個服務器和客戶端。 他們正在建立連接,然后該服務器每秒發送 1MB 文本文件。 服務器和客戶端代碼如下。 我已經測試了很長時間,發現沒有數據丟失。 我稍微修改了上面的回答。
服務器代碼:
package com.dd.server;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.concurrent.TimeUnit;
public class Server {
public static void main(String[] args) throws InterruptedException {
try {
byte[] done = new byte[3];
String str = "done"; //randomly anything
done = str.getBytes();
ServerSocket ss = new ServerSocket(5000);
Socket socket = ss.accept();
byte[] mybytearray = new byte[4096];
OutputStream os = socket.getOutputStream();
TimeUnit.SECONDS.sleep(5);
while(true) {
DataOutputStream dos = new DataOutputStream(os);
File myFile= new File("I:\\MY-LEARNINGS\\JAVA\\Workspace\\server\\src\\com\\dd\\server\\gistfile1.txt");
dos.writeUTF(myFile.getName());
dos.writeLong(myFile.length());
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
DataInputStream dis = new DataInputStream(bis);
int read;
System.out.println("---------File Writing started----------");
int count = 0;
while((read = dis.read(mybytearray)) != -1){
dos.write(mybytearray, 0, read);
dos.flush();
++count;
System.out.println("Writing sub component of file. Step : "+count);
}
System.out.println("---------File Writing ended----------");
System.out.println("Flushing data DONE command sent.");
dis.close();
bis.close();
fis.close();
TimeUnit.SECONDS.sleep(1);
System.out.println("File transfer has been completed.");
dos.write(done, 0, 3);
dos.flush();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
客戶代碼:
package clientcom.dd.clent;
import java.io.DataInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
public class Client {
public static void main(String[] args) {
try {
Socket socket = new Socket("127.0.0.1", 5000);
InputStream in = socket.getInputStream();
DataInputStream dis = new DataInputStream(in);
while(true) {
FileOutputStream fos =
new FileOutputStream("I:\\MY-LEARNINGS\\JAVA\\Workspace\\client\\"+System.currentTimeMillis()+"-data.txt");
int read = 0;
byte[] mybytearray = new byte[4096];
while ((read = dis.read(mybytearray)) != -1 && read != 3) {
fos.write(mybytearray, 0, read);
fos.flush();
}
fos.close();
//System.out.println("The value of read : "+read);
// System.out.println("File has been received successfully.");
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
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