java socket传输文件 用RandomAccessFile和MappedByteBuffer读写

你可以使用RandomAccessFile和MappedByteBuffer来实现Java Socket文件传输。以下是一个简单的示例代码： ```java import java.io.*; import java.net.*; import java.nio.*; import java.nio.channels.*; public class FileTransferServer { public static void main(String[] args) { try { ServerSocketChannel serverSocketChannel = ServerSocketChannel.open(); serverSocketChannel.bind(new InetSocketAddress(8080)); System.out.println("等待客户端连接..."); SocketChannel socketChannel = serverSocketChannel.accept(); System.out.println("客户端已连接。"); File file = new File("example.txt"); RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw"); FileChannel fileChannel = randomAccessFile.getChannel(); long fileSize = file.length(); MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, fileSize); socketChannel.write(ByteBuffer.wrap(Long.toString(fileSize).getBytes())); System.out.println("开始传输文件..."); socketChannel.write(mappedByteBuffer); System.out.println("文件传输完成。"); socketChannel.close(); serverSocketChannel.close(); } catch (IOException e) { e.printStackTrace(); } } } ``` ```java import java.io.*; import java.net.*; import java.nio.*; import java.nio.channels.*; public class FileTransferClient { public static void main(String[] args) { try { SocketChannel socketChannel = SocketChannel.open(); socketChannel.connect(new InetSocketAddress("localhost", 8080)); ByteBuffer fileSizeBuffer = ByteBuffer.allocate(8); socketChannel.read(fileSizeBuffer); fileSizeBuffer.flip(); long fileSize = Long.parseLong(new String(fileSizeBuffer.array()).trim()); System.out.println("开始接收文件..."); RandomAccessFile randomAccessFile = new RandomAccessFile("received.txt", "rw"); FileChannel fileChannel = randomAccessFile.getChannel(); MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, fileSize); socketChannel.read(mappedByteBuffer); System.out.println("文件接收完成。"); socketChannel.close(); } catch (IOException e) { e.printStackTrace(); } } } ``` 其中，Server端将文件example.txt传输给Client端，并保存为received.txt。你可以根据需要修改文件名和路径。请确保Server端先运行，然后再运行Client端。这只是一个简单的示例，你可以根据自己的需求进行修改和扩展。