NIO实现文件批量上传
时间: 2024-03-21 19:41:01 浏览: 15
NIO(Non-blocking I/O)是Java中的一种I/O模型,它可以实现非阻塞式的I/O操作。使用NIO实现文件批量上传可以提高文件上传的效率,下面是一个简单的实现过程:
1. 创建ServerSocketChannel对象,并且绑定一个端口号。
2. 创建Selector对象,并且将ServerSocketChannel注册到Selector中,同时设置为非阻塞模式。
3. 在循环中,使用Selector的select()方法来监听事件。当有事件发生时,使用selectedKeys()方法来获取事件集合。
4. 对于每一个事件,判断其类型。如果是连接事件,就创建一个SocketChannel对象,并将其注册到Selector中,同时设置为非阻塞模式。如果是读事件,就从SocketChannel中读取数据,并将其保存到文件中。
5. 在客户端中,创建SocketChannel对象,并连接到服务器。然后将文件分成多个块,每个块都创建一个ByteBuffer对象,并将其写入SocketChannel中。
下面是一个简单的NIO文件上传的示例代码:
```
public class NIOFileUploadServer {
private static final int PORT = 8888;
private static final int BUFFER_SIZE = 1024;
private static final String UPLOAD_DIR = "D:\\upload\\";
public static void main(String[] args) throws IOException {
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.socket().bind(new InetSocketAddress(PORT));
serverSocketChannel.configureBlocking(false);
Selector selector = Selector.open();
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
while (true) {
int readyChannels = selector.select();
if (readyChannels == 0) {
continue;
}
Set<SelectionKey> selectedKeys = selector.selectedKeys();
Iterator<SelectionKey> keyIterator = selectedKeys.iterator();
while (keyIterator.hasNext()) {
SelectionKey key = keyIterator.next();
keyIterator.remove();
if (key.isAcceptable()) {
ServerSocketChannel serverChannel = (ServerSocketChannel) key.channel();
SocketChannel socketChannel = serverChannel.accept();
socketChannel.configureBlocking(false);
socketChannel.register(selector, SelectionKey.OP_READ);
} else if (key.isReadable()) {
SocketChannel socketChannel = (SocketChannel) key.channel();
ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);
FileChannel fileChannel = new FileOutputStream(UPLOAD_DIR + "test.txt").getChannel();
while (socketChannel.read(buffer) > 0) {
buffer.flip();
fileChannel.write(buffer);
buffer.clear();
}
fileChannel.close();
socketChannel.close();
}
}
}
}
}
```
客户端代码:
```
public class NIOFileUploadClient {
private static final String SERVER_IP = "localhost";
private static final int SERVER_PORT = 8888;
private static final int BUFFER_SIZE = 1024;
private static final String FILE_PATH = "D:\\test.txt";
public static void main(String[] args) throws IOException {
SocketChannel socketChannel = SocketChannel.open();
socketChannel.connect(new InetSocketAddress(SERVER_IP, SERVER_PORT));
socketChannel.configureBlocking(false);
FileChannel fileChannel = new FileInputStream(FILE_PATH).getChannel();
ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);
while (fileChannel.read(buffer) > 0) {
buffer.flip();
socketChannel.write(buffer);
buffer.clear();
}
fileChannel.close();
socketChannel.close();
}
}
```
需要注意的是,上述代码仅为示例,实际使用时需要添加必要的异常处理和错误处理。同时,文件上传时需要对文件进行分块,以免一次性上传过大的文件导致服务器负载过高。