Java 通过套接字发送和接收文件（字节 []）

file sockets java client

2022-08-31 14:17:23

我正在尝试开发一个非常简单的客户端/服务器，其中客户端将文件转换为字节，将其发送到服务器，然后将字节转换回文件。

目前，该程序只是创建一个空文件。我不是一个出色的Java开发人员，所以任何帮助都非常感谢。

这是接收客户端发送的内容的服务器部分。

ServerSocket serverSocket = null;

    serverSocket = new ServerSocket(4444);


    Socket socket = null;
    socket = serverSocket.accept();

    DataOutputStream out = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
    DataInputStream in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
    byte[] bytes = new byte[1024];

    in.read(bytes);
    System.out.println(bytes);

    FileOutputStream fos = new FileOutputStream("C:\\test2.xml");
    fos.write(bytes);

这是客户端部分

Socket socket = null;
    DataOutputStream out = null;
    DataInputStream in = null;
    String host = "127.0.0.1";     

    socket = new Socket(host, 4444);
    out = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
    in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));

    File file = new File("C:\\test.xml");
    //InputStream is = new FileInputStream(file);
    // Get the size of the file
    long length = file.length();
    if (length > Integer.MAX_VALUE) {
        System.out.println("File is too large.");
    }
    byte[] bytes = new byte[(int) length];

    //out.write(bytes);
    System.out.println(bytes);

    out.close();
    in.close();
    socket.close();

答案 1

在 Java 中复制流的正确方法如下：

int count;
byte[] buffer = new byte[8192]; // or 4096, or more
while ((count = in.read(buffer)) > 0)
{
  out.write(buffer, 0, count);
}

希望我每次在论坛上发布它时都有一美元。

答案 2

感谢您的帮助。我现在已经设法让它工作，所以我想我会发布，以便其他人可以用来帮助他们。

服务器：

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;

        try {
            serverSocket = new ServerSocket(4444);
        } catch (IOException ex) {
            System.out.println("Can't setup server on this port number. ");
        }

        Socket socket = null;
        InputStream in = null;
        OutputStream out = null;
        
        try {
            socket = serverSocket.accept();
        } catch (IOException ex) {
            System.out.println("Can't accept client connection. ");
        }
        
        try {
            in = socket.getInputStream();
        } catch (IOException ex) {
            System.out.println("Can't get socket input stream. ");
        }

        try {
            out = new FileOutputStream("M:\\test2.xml");
        } catch (FileNotFoundException ex) {
            System.out.println("File not found. ");
        }

        byte[] bytes = new byte[16*1024];

        int count;
        while ((count = in.read(bytes)) > 0) {
            out.write(bytes, 0, count);
        }

        out.close();
        in.close();
        socket.close();
        serverSocket.close();
    }
}

和客户端：

public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = null;
        String host = "127.0.0.1";

        socket = new Socket(host, 4444);
        
        File file = new File("M:\\test.xml");
        // Get the size of the file
        long length = file.length();
        byte[] bytes = new byte[16 * 1024];
        InputStream in = new FileInputStream(file);
        OutputStream out = socket.getOutputStream();
        
        int count;
        while ((count = in.read(bytes)) > 0) {
            out.write(bytes, 0, count);
        }

        out.close();
        in.close();
        socket.close();
    }
}