基于socket的Java多文件传输

好的，尝试通过套接字传输指定的文件目录，从arraylist中删除目录对象，这样只剩下文件，然后通过同一套接字逐个传输它们。这里的arraylist只填充了文件，没有目录。这是客户端和服务器的接收和发送代码。除了所有数据都写入第一个文件之外，代码运行正常，没有错误。后续文件在服务器文件夹中创建，但它们是0字节。如有任何意见，将不胜感激

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();

    }


}

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();
    }


}

public void receive（）{
试一试{
DataInputStream dis=新的DataInputStream（新的BufferedInputStream（socket.getInputStream（））；
DataOutputStream dos=新的DataOutputStream（新的BufferedOutputStream（socket.getOutputStream（））；
//从客户端读取文件数
int number=dis.readInt（）；
ArrayList文件=新的ArrayList（编号）；
System.out.println（“要接收的文件数：“+Number”）；
//读取文件名，将文件添加到arraylist
for（int i=0；i

这是用于发送文件的客户端代码

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();

    }


}

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();
    }


}

public void发送（ArrayListfiles）{
试一试{
DataInputStream dis=新的DataInputStream（新的BufferedInputStream（socket.getInputStream（））；
DataOutputStream dos=新的DataOutputStream（新的BufferedOutputStream（socket.getOutputStream（））；
System.out.println（files.size（））；
//将文件数写入服务器
dos.writeInt（files.size（））；
dos.flush（）；
//写文件名
对于（int i=0；i

您正在读取套接字，直到

read（）

返回-1。这是流结束条件（EOS）。当对等方关闭连接时发生EOS。当它写完一个文件时就不会了

您需要在每个文件之前发送文件大小。您已经在对文件计数执行类似的操作。然后确保您读取该文件的准确字节数：

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();

---

您可以将所有这些包含在一个循环中，该循环在

readUTF（）

抛出

EOFEException

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）

。

您正在读取套接字，直到

read（）

返回-1。这是流结束条件（EOS）。当对等方关闭连接时发生EOS。当它写完一个文件时就不会了

您需要在每个文件之前发送文件大小。您已经在对文件计数执行类似的操作。然后确保您读取该文件的准确字节数：

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();

---

您可以将所有这些包含在一个循环中，该循环在

readUTF（）

抛出

EOFEException

时终止。相反，在发送数据之前，您必须在发送方调用

writeUTF（文件名）

和

writeLong（文件大小）

。

我这样做的，它工作得很好，您可以看一下：

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();

byte[]done=新字节[3]；
String str=“完成”//随便什么
done=str.getBytes（）；
对于（int i=0；i

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();
}

for（int i=0；i

我是这样做的，它工作得很好，您可以看看：

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();

byte[]done=新字节[3]；
String str=“完成”//随便什么
done=str.getB