基于socket的Java多文件传输
基于socket的Java多文件传输
提问于 2012-04-29 05:30:09
好的，尝试通过套接字传输指定的文件目录，从数组列表中删除目录对象，这样就只剩下文件，并通过相同的套接字逐个传输它们。这里的arraylist只包含文件，没有目录。下面是客户端和服务器的接收和发送代码。代码运行良好，没有错误，只是所有数据都被写入第一个文件。后续文件是在服务器文件夹中创建的，但它们是0字节。我们将非常感谢您的任何意见。
这是用于接收文件的服务器代码
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();
}
}这是用于发送文件的客户端代码
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();
}
}回答 3
Stack Overflow用户
回答已采纳
发布于 2012-04-29 15:37:33
在read()返回-1之前，您一直在读取套接字。这是流结束条件(EOS)。当对等方关闭连接时，就会发生EOS。当它写完一个文件后就不会了。
您需要在每个文件之前发送文件大小。您已经对文件数执行了类似的操作。然后确保您准确读取了该文件的字节数：
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();您可以将所有这些都包含在一个循环中，该循环在readUTF()抛出EOFException时终止。相反，在发送数据之前，您必须在发送方调用writeUTF(filename)和writeLong(filesize)。
Stack Overflow用户
发布于 2012-04-29 15:37:57
我是这样做的，它工作得很好，你可以看看：
发送
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();接收
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();
}Stack Overflow用户
发布于 2020-10-25 06:14:03
我已经创建了一个服务器和客户端。他们正在建立连接，然后服务器每秒发送1MB的文本文件。服务器和客户端代码如下。我测试了长持续时间，发现没有数据丢失。我对上面的回答做了一些修改。
服务器代码：
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();
}
}
}客户端代码：
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();
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/10367698
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