import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import org.junit.Test;
/**
* 一、使用 NIO 完成网络通信的三个核心:
*
* 1. 通道(Channel):负责连接
*
* java.nio.channels.Channel 接口:
* |--SelectableChannel
* |--SocketChannel
* |--ServerSocketChannel
* |--DatagramChannel
*
* |--Pipe.SinkChannel
* |--Pipe.SourceChannel
*
* 2. 缓冲区(Buffer):负责数据的存取
*
* 3. 选择器(Selector):是 SelectableChannel 的多路复用器。用于监控 SelectableChannel 的 IO 状况
*
*/
public class TestBlockingNIO {
//客户端
@Test
public void client() throws IOException{
//1. 获取通道
SocketChannel sChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 9898));
FileChannel inChannel = FileChannel.open(Paths.get("1.jpg"), StandardOpenOption.READ);
//2. 分配指定大小的缓冲区
ByteBuffer buf = ByteBuffer.allocate(1024);
//3. 读取本地文件,并发送到服务端
while(inChannel.read(buf) != -1){
buf.flip();
sChannel.write(buf);
buf.clear();
}
//4. 关闭通道
inChannel.close();
sChannel.close();
}
//服务端
@Test
public void server() throws IOException{
//1. 获取通道
ServerSocketChannel ssChannel = ServerSocketChannel.open();
FileChannel outChannel = FileChannel.open(Paths.get("5.jpg"), StandardOpenOption.WRITE, StandardOpenOption.CREATE);
//2. 绑定连接
ssChannel.bind(new InetSocketAddress(9898));
//3. 获取客户端连接的通道
SocketChannel sChannel = ssChannel.accept();
//4. 分配指定大小的缓冲区
ByteBuffer buf = ByteBuffer.allocate(1024);
//5. 接收客户端的数据,并保存到本地
while(sChannel.read(buf) != -1){
buf.flip();
outChannel.write(buf);
buf.clear();
}
//6. 关闭通道
sChannel.close();
outChannel.close();
ssChannel.close();
}
}