还记得之前介绍NIO时对比传统IO的一大特点吗？就是NIO是非阻塞式的，这篇文章带大家来看一下非阻塞的网络操作。
补充：以数组的形式使用缓冲区
package testnio;import java.io.IOException;import java.io.RandomAccessFile;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;public class TestBufferArray { public static void main(String[] args) throws IOException {
RandomAccessFile raf1=new RandomAccessFile("D:/1.txt","rw");
//1.获取通道
FileChannel channel1=raf1.getChannel();
//2.创建缓冲区数组
ByteBuffer buf1=ByteBuffer.allocate(512);
ByteBuffer buf2=ByteBuffer.allocate(512);
ByteBuffer[] bufs= {buf1,buf2}; //3.将数据读入缓冲区数组
channel1.read(bufs);
for (ByteBuffer byteBuffer : bufs) {
byteBuffer.flip();
}
System.out.println(new String(bufs[0].array(),0,bufs[0].limit()));
System.out.println("-----------");
System.out.println(new String(bufs[1].array(),0,bufs[1].limit()));
//写入缓冲区数组到通道中
RandomAccessFile raf2=new RandomAccessFile("D:/2.txt","rw");
FileChannel channel2=raf2.getChannel();
channel2.write(bufs);
}
}使用NIO实现阻塞式网络通信
TCP协议的网络通信传统实现方式是通过套接字编程(Socket和ServerSocket)，NIO实现TCP网络通信需要用到 Channel 接口的两个实现类：SocketChannel和ServerSocketChannel
使用NIO实现阻塞式网络通信
客户端
package com.jikedaquan.blockingnio;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;import java.nio.channels.SocketChannel;import java.nio.file.Paths;import java.nio.file.StandardOpenOption;public class Client { public static void main(String[] args) {
SocketChannel sChannel=null;
FileChannel inChannel=null; try { //1、获取通道
sChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 1666)); //用于读取文件
inChannel = FileChannel.open(Paths.get("F:/a.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，发送到服务器端
while(inChannel.read(buf)!=-1) {
buf.flip();
sChannel.write(buf);
buf.clear();
}
} catch (IOException e) {
e.printStackTrace();
}finally { //关闭通道
if (inChannel!=null) { try {
inChannel.close();
} catch (IOException e) {
e.printStackTrace();
}
} if(sChannel!=null) { try {
sChannel.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}new InetSocketAddress("127.0.0.1", 1666) 用于向客户端套接字通道(SocketChannel)绑定要连接地址和端口
服务端
package com.jikedaquan.blockingnio;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;public class Server { public static void main(String[] args) {
ServerSocketChannel ssChannel=null;
FileChannel outChannel=null;
SocketChannel sChannel=null; try { //1、获取通道
ssChannel = ServerSocketChannel.open(); //用于保存文件的通道
outChannel = FileChannel.open(Paths.get("F:/b.jpg"), StandardOpenOption.WRITE,StandardOpenOption.CREATE); //2、绑定要监听的端口号
ssChannel.bind(new InetSocketAddress(1666)); //3、获取客户端连接的通道
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();
}
} catch (IOException e) {
e.printStackTrace();
}finally { //6、关闭通道
if(sChannel!=null) { try {
sChannel.close();
} catch (IOException e) {
e.printStackTrace();
}
} if(outChannel!=null) { try {
outChannel.close();
} catch (IOException e) {
e.printStackTrace();
}
} if(ssChannel!=null) { try {
ssChannel.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
作者：极客大全
链接：https://www.jianshu.com/p/7ddccc674cd8
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