NIO ServerSocketChannel ScoketChannel

package com.yb.nio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;

public class NIOServer {

    /*标识数字*/
    private  int flag = 0;
    /*缓冲区大小*/
    private  int BLOCK = 4096;
    /*接受数据缓冲区*/
    private  ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);
    /*发送数据缓冲区*/
    private  ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);
    private  Selector selector;

    public NIOServer(int port) throws IOException {
        // 打开服务器套接字通道
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        // 服务器配置为非阻塞
        serverSocketChannel.configureBlocking(false);
        // 检索与此通道关联的服务器套接字
        ServerSocket serverSocket = serverSocketChannel.socket();
        // 进行服务的绑定
        serverSocket.bind(new InetSocketAddress(port));
        // 通过open()方法找到Selector
        selector = Selector.open();
        // 注册到selector，等待连接
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        System.out.println("Server Start----8888:");
    }

    // 监听
    private void listen() throws IOException {
        while (true) {
            // 选择一组键，并且相应的通道已经打开
            selector.select();
            // 返回此选择器的已选择键集。
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                SelectionKey selectionKey = iterator.next();
                iterator.remove();
                handleKey(selectionKey);
            }
        }
    }

    // 处理请求
    private void handleKey(SelectionKey selectionKey) throws IOException {
        // 接受请求
        ServerSocketChannel server = null;
        SocketChannel client = null;
        String receiveText;
        String sendText;
        int count=0;
        // 测试此键的通道是否已准备好接受新的套接字连接。
        if (selectionKey.isAcceptable()) {
            // 返回为之创建此键的通道。
            server = (ServerSocketChannel) selectionKey.channel();
            // 接受到此通道套接字的连接。
            // 此方法返回的套接字通道（如果有）将处于阻塞模式。
            client = server.accept();
            // 配置为非阻塞
            client.configureBlocking(false);
            // 注册到selector，等待连接
            client.register(selector, SelectionKey.OP_READ);
        } else if (selectionKey.isReadable()) {
            // 返回为之创建此键的通道。
            client = (SocketChannel) selectionKey.channel();
            //将缓冲区清空以备下次读取
            receivebuffer.clear();
            //读取服务器发送来的数据到缓冲区中
            count = client.read(receivebuffer);
            if (count > 0) {
                receiveText = new String( receivebuffer.array(),0,count);
                System.out.println("服务器端接受客户端数据--:"+receiveText);
                client.register(selector, SelectionKey.OP_WRITE);
            }
        } else if (selectionKey.isWritable()) {
            //将缓冲区清空以备下次写入
            sendbuffer.clear();
            // 返回为之创建此键的通道。
            client = (SocketChannel) selectionKey.channel();
            sendText="message from server--" + flag++;
            //向缓冲区中输入数据
            sendbuffer.put(sendText.getBytes());
             //将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位
            sendbuffer.flip();
            //输出到通道
            client.write(sendbuffer);
            System.out.println("服务器端向客户端发送数据--："+sendText);
            client.register(selector, SelectionKey.OP_READ);
        }
    }

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        int port = 8888;
        NIOServer server = new NIOServer(port);
        server.listen();
    }
}

package com.yb.nio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;

public class NIOClient {

    /*标识数字*/
    private static int flag = 0;
    /*缓冲区大小*/
    private static int BLOCK = 4096;
    /*接受数据缓冲区*/
    private static ByteBuffer sendbuffer = ByteBuffer.allocate(BLOCK);
    /*发送数据缓冲区*/
    private static ByteBuffer receivebuffer = ByteBuffer.allocate(BLOCK);
    /*服务器端地址*/
    private final static InetSocketAddress SERVER_ADDRESS = new InetSocketAddress(
            "localhost", 8888);

    public static void main(String[] args) throws IOException {
        // 打开socket通道
        SocketChannel socketChannel = SocketChannel.open();
        // 设置为非阻塞方式
        socketChannel.configureBlocking(false);
        // 打开选择器
        Selector selector = Selector.open();
        // 注册连接服务端socket动作
        socketChannel.register(selector, SelectionKey.OP_CONNECT);
        // 连接
        socketChannel.connect(SERVER_ADDRESS);
        // 分配缓冲区大小内存

        Set<SelectionKey> selectionKeys;
        Iterator<SelectionKey> iterator;
        SelectionKey selectionKey;
        SocketChannel client;
        String receiveText;
        String sendText;
        int count=0;

        while (true) {
            //选择一组键，其相应的通道已为 I/O 操作准备就绪。
            //此方法执行处于阻塞模式的选择操作。
            selector.select();
            //返回此选择器的已选择键集。
            selectionKeys = selector.selectedKeys();
            //System.out.println(selectionKeys.size());
            iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                selectionKey = iterator.next();
                if (selectionKey.isConnectable()) {
                    System.out.println("client connect");
                    client = (SocketChannel) selectionKey.channel();
                    // 判断此通道上是否正在进行连接操作。
                    // 完成套接字通道的连接过程。
                    if (client.isConnectionPending()) {
                        client.finishConnect();
                        System.out.println("完成连接!");
                        sendbuffer.clear();
                        sendbuffer.put("Hello,Server".getBytes());
                        sendbuffer.flip();
                        client.write(sendbuffer);
                    }
                    client.register(selector, SelectionKey.OP_READ);
                } else if (selectionKey.isReadable()) {
                    client = (SocketChannel) selectionKey.channel();
                    //将缓冲区清空以备下次读取
                    receivebuffer.clear();
                    //读取服务器发送来的数据到缓冲区中
                    count=client.read(receivebuffer);
                    if(count>0){
                        receiveText = new String( receivebuffer.array(),0,count);
                        System.out.println("客户端接受服务器端数据--:"+receiveText);
                        client.register(selector, SelectionKey.OP_WRITE);
                    }

                } else if (selectionKey.isWritable()) {
                    sendbuffer.clear();
                    client = (SocketChannel) selectionKey.channel();
                    sendText = "message from client--" + (flag++);
                    sendbuffer.put(sendText.getBytes());
                     //将缓冲区各标志复位,因为向里面put了数据标志被改变要想从中读取数据发向服务器,就要复位
                    sendbuffer.flip();
                    client.write(sendbuffer);
                    System.out.println("客户端向服务器端发送数据--："+sendText);
                    client.register(selector, SelectionKey.OP_READ);
                }
            }
            selectionKeys.clear();
        }
    }
}

package com.yb.nio;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * NIO读取百万级别文件
 * @author Chillax
 *
 */
public class NIO {

    public static void main(String args[]) throws Exception {

        int bufSize = 10;//一次读取的字节长度
        File fin = new File("E:/a.txt");//读取的文件
        File fout = new File("E:/b.txt");//写出的文件
        Date startDate = new Date();
        FileChannel fcin = new RandomAccessFile(fin, "r").getChannel();
        ByteBuffer rBuffer = ByteBuffer.allocate(bufSize);

        FileChannel fcout = new RandomAccessFile(fout, "rws").getChannel();
        ByteBuffer wBuffer = ByteBuffer.allocateDirect(bufSize);

        readFileByLine(bufSize, fcin, rBuffer, fcout, wBuffer);
        Date endDate = new Date();

        System.out.print(startDate+"|"+endDate);//测试执行时间
        if(fcin.isOpen()){
            fcin.close();
        }
        if(fcout.isOpen()){
            fcout.close();
        }
    }

    public static void readFileByLine(int bufSize, FileChannel fcin,
            ByteBuffer rBuffer, FileChannel fcout, ByteBuffer wBuffer) {
        String enter = "\n";
        List<String> dataList = new ArrayList<String>();//存储读取的每行数据
        byte[] lineByte = new byte[0];

        //String encode = "GBK";
        String encode = "UTF-8";
        try {
            //temp：由于是按固定字节读取，在一次读取中，第一行和最后一行经常是不完整的行，因此定义此变量来存储上次的最后一行和这次的第一行的内容，
            //并将之连接成完成的一行，否则会出现汉字被拆分成2个字节，并被提前转换成字符串而乱码的问题
            byte[] temp = new byte[0];
            while (fcin.read(rBuffer) != -1) {//fcin.read(rBuffer)：从文件管道读取内容到缓冲区(rBuffer)
                int rSize = rBuffer.position();//读取结束后的位置，相当于读取的长度
                byte[] bs = new byte[rSize];//用来存放读取的内容的数组
                rBuffer.rewind();//将position设回0,所以你可以重读Buffer中的所有数据,此处如果不设置,无法使用下面的get方法
                rBuffer.get(bs);//相当于rBuffer.get(bs,0,bs.length())：从position初始位置开始相对读,读bs.length个byte,并写入bs[0]到bs[bs.length-1]的区域
                rBuffer.clear();

                int startNum = 0;
                int LF = 10;//换行符
                int CR = 13;//回车符
                boolean hasLF = false;//是否有换行符
                for(int i = 0; i < rSize; i++){
                    if(bs[i] == LF){
                        hasLF = true;
                        int tempNum = temp.length;
                        int lineNum = i - startNum;
                        lineByte = new byte[tempNum + lineNum];//数组大小已经去掉换行符

                        System.arraycopy(temp, 0, lineByte, 0, tempNum);//填充了lineByte[0]~lineByte[tempNum-1]
                        temp = new byte[0];
                        System.arraycopy(bs, startNum, lineByte, tempNum, lineNum);//填充lineByte[tempNum]~lineByte[tempNum+lineNum-1]

                        String line = new String(lineByte, 0, lineByte.length, encode);//一行完整的字符串(过滤了换行和回车)
                        dataList.add(line);
//                        System.out.println(line);
                        writeFileByLine(fcout, wBuffer, line + enter);

                        //过滤回车符和换行符
                        if(i + 1 < rSize && bs[i + 1] == CR){
                            startNum = i + 2;
                        }else{
                            startNum = i + 1;
                        }

                    }
                }
                if(hasLF){
                    temp = new byte[bs.length - startNum];
                    System.arraycopy(bs, startNum, temp, 0, temp.length);
                }else{//兼容单次读取的内容不足一行的情况
                    byte[] toTemp = new byte[temp.length + bs.length];
                    System.arraycopy(temp, 0, toTemp, 0, temp.length);
                    System.arraycopy(bs, 0, toTemp, temp.length, bs.length);
                    temp = toTemp;
                }
            }
            if(temp != null && temp.length > 0){//兼容文件最后一行没有换行的情况
                String line = new String(temp, 0, temp.length, encode);
                dataList.add(line);
//                System.out.println(line);
                writeFileByLine(fcout, wBuffer, line + enter);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 写到文件上
     * @param fcout
     * @param wBuffer
     * @param line
     */
    @SuppressWarnings("static-access")
    public static void writeFileByLine(FileChannel fcout, ByteBuffer wBuffer,
            String line) {
        try {
            fcout.write(wBuffer.wrap(line.getBytes("UTF-8")), fcout.size());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}