Java网络编程（一）

public class InetAddressDemo {
    public static void main(String[] args) throws UnknownHostException {
    //InetAddress address = InetAddress.getByName("itheima");
        InetAddress address = InetAddress.getByName("192.168.1.66");
        //public String getHostName()：获取此IP地址的主机名
        String name = address.getHostName();
        //public String getHostAddress()：返回文本显示中的IP地址字符串
        String ip = address.getHostAddress();
        System.out.println("主机名：" + name);
        System.out.println("IP地址：" + ip);
    }
}

public class SendDemo {
    public static void main(String[] args) throws IOException {
        //创建发送端的Socket对象(DatagramSocket)
        // DatagramSocket() 构造数据报套接字并将其绑定到本地主机上的任何可用端口
        DatagramSocket ds = new DatagramSocket();
        //创建数据，并把数据打包
        //DatagramPacket(byte[] buf, int length, InetAddress address, int port)
        //构造一个数据包，发送长度为 length的数据包到指定主机上的指定端口号。
        byte[] bys = "hello,udp,我来了".getBytes();
        DatagramPacket dp = new DatagramPacket(bys,bys.length,InetAddress.getByName("127.0.0.1"),10086);
        //调用DatagramSocket对象的方法发送数据
        //void send(DatagramPacket p) 从此套接字发送数据报包
        ds.send(dp);
        //关闭发送端
        //void close() 关闭此数据报套接字
        ds.close();
    }
}

public class ReceiveDemo {
    public static void main(String[] args) throws IOException {
        //创建接收端的Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket(12345);
        //创建一个数据包，用于接收数据
        byte[] bys = new byte[1024];
        DatagramPacket dp = new DatagramPacket(bys, bys.length);
        //调用DatagramSocket对象的方法接收数据
        ds.receive(dp);
        //解析数据包，并把数据在控制台显示
        System.out.println("数据是：" + new String(dp.getData(), 0,                                             dp.getLength()));
        }
    }
}

/*
    UDP发送数据：
        数据来自于键盘录入，直到输入的数据是886，发送数据结束
 */
public class SendDemo {
    public static void main(String[] args) throws IOException {
        //创建发送端的Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket();
        //键盘录入数据
        Scanner sc = new Scanner(System.in);
        while (true) {
            String s = sc.nextLine();
            //输入的数据是886，发送数据结束
            if ("886".equals(s)) {
                break;
            }
            //创建数据，并把数据打包
            byte[] bys = s.getBytes();
            DatagramPacket dp = new DatagramPacket(bys, bys.length, InetAddress.getByName("192.168.1.66"), 12345);
            //调用DatagramSocket对象的方法发送数据
            ds.send(dp);
        }
        //关闭发送端
        ds.close();
    }
}
/*
    UDP接收数据：
        因为接收端不知道发送端什么时候停止发送，故采用死循环接收
 */
public class ReceiveDemo {
    public static void main(String[] args) throws IOException {
        //创建接收端的Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket(12345);
        while (true) {
            //创建一个数据包，用于接收数据
            byte[] bys = new byte[1024];
            DatagramPacket dp = new DatagramPacket(bys, bys.length);
            //调用DatagramSocket对象的方法接收数据
            ds.receive(dp);
            //解析数据包，并把数据在控制台显示
            System.out.println("数据是：" + new String(dp.getData(), 0, dp.getLength()));
        }
        //关闭接收端
//        ds.close();
    }
}

// 发送端
public class ClinetDemo {
    public static void main(String[] args) throws IOException {
        // 1. 创建发送端的Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket();
        String s = "hello 组播";
        byte[] bytes = s.getBytes();
        InetAddress address = InetAddress.getByName("224.0.1.0");
        int port = 10000;
        // 2. 创建数据，并把数据打包(DatagramPacket)
        DatagramPacket dp = new DatagramPacket(bytes,bytes.length,address,port);
        // 3. 调用DatagramSocket对象的方法发送数据(在单播中,这里是发给指定IP的电脑但是在组播当中,这里是发给组播地址)
        ds.send(dp);
        // 4. 释放资源
        ds.close();
    }
}
// 接收端
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        // 1. 创建接收端Socket对象(MulticastSocket)
        MulticastSocket ms = new MulticastSocket(10000);
        // 2. 创建一个箱子,用于接收数据
        DatagramPacket dp = new DatagramPacket(new byte[1024],1024);
        // 3. 把当前计算机绑定一个组播地址,表示添加到这一组中.
        ms.joinGroup(InetAddress.getByName("224.0.1.0"));
        // 4. 将数据接收到箱子中
        ms.receive(dp);
        // 5. 解析数据包,并打印数据
        byte[] data = dp.getData();
        int length = dp.getLength();
        System.out.println(new String(data,0,length));
        // 6. 释放资源
        ms.close();
    }
}

// 发送端
public class ClientDemo {
    public static void main(String[] args) throws IOException {
        // 1. 创建发送端Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket();
    // 2. 创建存储数据的箱子,将广播地址封装进去
        String s = "广播 hello";
        byte[] bytes = s.getBytes();
        InetAddress address = InetAddress.getByName("255.255.255.255");
        int port = 10000;
        DatagramPacket dp = new DatagramPacket(bytes,bytes.length,address,port);
    // 3. 发送数据
        ds.send(dp);
    // 4. 释放资源
        ds.close();
    }
}
// 接收端
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        // 1. 创建接收端的Socket对象(DatagramSocket)
        DatagramSocket ds = new DatagramSocket(10000);
        // 2. 创建一个数据包，用于接收数据
        DatagramPacket dp = new DatagramPacket(new byte[1024],1024);
        // 3. 调用DatagramSocket对象的方法接收数据
        ds.receive(dp);
        // 4. 解析数据包，并把数据在控制台显示
        byte[] data = dp.getData();
        int length = dp.getLength();
        System.out.println(new String(data,0,length));
        // 5. 关闭接收端
        ds.close();
    }
}

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //创建客户端的Socket对象(Socket)
        //Socket(String host, int port) 创建流套接字并将其连接到指定主机上的指定端口号
        Socket s = new Socket("127.0.0.1",10000);
        //获取输出流，写数据
        //OutputStream getOutputStream() 返回此套接字的输出流
        OutputStream os = s.getOutputStream();
        os.write("hello,tcp,我来了".getBytes());
        //释放资源
        s.close();
    }
}

public class ServerDemo {
    public static void main(String[] args) throws IOException {
        //创建服务器端的Socket对象(ServerSocket)
        //ServerSocket(int port) 创建绑定到指定端口的服务器套接字
        ServerSocket ss = new ServerSocket(10000);
        //Socket accept() 侦听要连接到此套接字并接受它
        Socket s = ss.accept();
        //获取输入流，读数据，并把数据显示在控制台
        InputStream is = s.getInputStream();
        byte[] bys = new byte[1024];
        int len = is.read(bys);
        String data = new String(bys,0,len);
        System.out.println("数据是：" + data);
        //释放资源
        s.close();
        ss.close();
    }
}

// 客户端
public class ClientDemo {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("127.0.0.1",10000);
        OutputStream os = socket.getOutputStream();
        os.write("hello".getBytes());
       // os.close();如果在这里关流,会导致整个socket都无法使用
        socket.shutdownOutput();//仅仅关闭输出流.并写一个结束标记,对socket没有任何影响
        BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String line;
        while((line = br.readLine())!=null){
            System.out.println(line);
        }
        br.close();
        os.close();
        socket.close();
    }
}
// 服务器
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        Socket accept = ss.accept();
        InputStream is = accept.getInputStream();
        int b;
        while((b = is.read())!=-1){
            System.out.println((char) b);
        }
        System.out.println("看看我执行了吗?");
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(accept.getOutputStream()));
        bw.write("你谁啊?");
        bw.newLine();
        bw.flush();
        bw.close();
        is.close();
        accept.close();
        ss.close();
    }
}

// 客户端
public class ClientDemo {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("127.0.0.1",10000);
        //是本地的流,用来读取本地文件的.
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream("socketmodule\\ClientDir\\1.jpg"));
        //写到服务器 --- 网络中的流
        OutputStream os = socket.getOutputStream();
        BufferedOutputStream bos = new BufferedOutputStream(os);
        int b;
        while((b = bis.read())!=-1){
            bos.write(b);//通过网络写到服务器中
        }
        bos.flush();
        //给服务器一个结束标记,告诉服务器文件已经传输完毕
        socket.shutdownOutput();
        BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String line;
        while((line = br.readLine()) !=null){
            System.out.println(line);
        }
        bis.close();
        socket.close();
    }
}
// 服务器
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        Socket accept = ss.accept();
        //网络中的流,从客户端读取数据的
        BufferedInputStream bis = new BufferedInputStream(accept.getInputStream());
        //本地的IO流,把数据写到本地中,实现永久化存储
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("socketmodule\\ServerDir\\copy.jpg"));
        int b;
        while((b = bis.read()) !=-1){
            bos.write(b);
        }
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(accept.getOutputStream()));
        bw.write("上传成功");
        bw.newLine();
        bw.flush();
        bos.close();
        accept.close();
        ss.close();
    }
}

// 服务器代码如下,客户端代码同上个案例,此处不再给出
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        while (true) {
            Socket accept = ss.accept();
            //网络中的流,从客户端读取数据的
            BufferedInputStream bis = new BufferedInputStream(accept.getInputStream());
            //本地的IO流,把数据写到本地中,实现永久化存储
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("optimizeserver\\ServerDir\\copy.jpg"));
            int b;
            while((b = bis.read()) !=-1){
                bos.write(b);
            }
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(accept.getOutputStream()));
            bw.write("上传成功");
            bw.newLine();
            bw.flush();
            bos.close();
            accept.close();
        }
        //ss.close();
    }
}

// 服务器代码如下,客户端代码同上个案例,此处不再给出
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        while (true) {
            Socket accept = ss.accept();
            //网络中的流,从客户端读取数据的
            BufferedInputStream bis = new BufferedInputStream(accept.getInputStream());
            //本地的IO流,把数据写到本地中,实现永久化存储
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("optimizeserver\\ServerDir\\" + UUID.randomUUID().toString() + ".jpg"));
            int b;
            while((b = bis.read()) !=-1){
                bos.write(b);
            }
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(accept.getOutputStream()));
            bw.write("上传成功");
            bw.newLine();
            bw.flush();
            bos.close();
            accept.close();
        }
        //ss.close();
    }
}

// 线程任务类
public class ThreadSocket implements Runnable {
    private Socket acceptSocket;
    public ThreadSocket(Socket accept) {
        this.acceptSocket = accept;
    }
    @Override
    public void run() {
        BufferedOutputStream bos = null;
        try {
            //网络中的流,从客户端读取数据的
            BufferedInputStream bis = new BufferedInputStream(acceptSocket.getInputStream());
            //本地的IO流,把数据写到本地中,实现永久化存储
            bos = new BufferedOutputStream(new FileOutputStream("optimizeserver\\ServerDir\\" + UUID.randomUUID().toString() + ".jpg"));
            int b;
            while((b = bis.read()) !=-1){
                bos.write(b);
            }
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(acceptSocket.getOutputStream()));
            bw.write("上传成功");
            bw.newLine();
            bw.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(bos != null){
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (acceptSocket != null){
                try {
                    acceptSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}
// 服务器代码
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        while (true) {
            Socket accept = ss.accept();
            ThreadSocket ts = new ThreadSocket(accept);
            new Thread(ts).start();
        }
        //ss.close();
    }
}

// 服务器代码如下,线程任务类代码同上,此处不再给出
public class ServerDemo {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(10000);
        ThreadPoolExecutor pool = new ThreadPoolExecutor(
                3,//核心线程数量
                10,   //线程池的总数量
                60,   //临时线程空闲时间
                TimeUnit.SECONDS, //临时线程空闲时间的单位
                new ArrayBlockingQueue<>(5),//阻塞队列
                Executors.defaultThreadFactory(),//创建线程的方式
                new ThreadPoolExecutor.AbortPolicy()//任务拒绝策略
        );
        while (true) {
            Socket accept = ss.accept();
            ThreadSocket ts = new ThreadSocket(accept);
            //new Thread(ts).start();
            pool.submit(ts);
        }
        //ss.close();
    }
}

public class CreateByteBufferDemo1 {
    public static void main(String[] args) {
        //method1();
        //method2();
        ByteBuffer wrap = ByteBuffer.wrap("aaa".getBytes());
        for (int i = 0; i < 3; i++) {
            System.out.println(wrap.get());
        }
    }
    private static void method2() {
        byte [] bytes = {97,98,99};
        ByteBuffer byteBuffer2 = ByteBuffer.wrap(bytes);
        //缓冲区的长度3
        //缓冲区里面的内容就是字节数组的内容.
        for (int i = 0; i < 3; i++) {
            System.out.println(byteBuffer2.get());
        }
        System.out.println(byteBuffer2.get());
    }
    private static void method1() {
        ByteBuffer byteBuffer1 = ByteBuffer.allocate(5);
        //get
        for (int i = 0; i < 5; i++) {
            System.out.println(byteBuffer1.get());
        }
        System.out.println(byteBuffer1.get());
    }
}

public class ByteBufferDemo2 {
    public static void main(String[] args) {
//        int position()      当前要操作的索引
//        int limit()       最多能操作到哪个索引
//        int capacity()      缓冲区的总长度
        ByteBuffer byteBuffer = ByteBuffer.allocate(10);
        System.out.println(byteBuffer.position());//0
        System.out.println(byteBuffer.limit());//10
        System.out.println(byteBuffer.capacity());//10
//        put(byte b)     一次添加一个字节
//        byteBuffer.put((byte) 97);
//        System.out.println(byteBuffer.position());
//        System.out.println(byteBuffer.limit());
//        System.out.println(byteBuffer.capacity());
//        put(byte[] src)    一次添加一个字节数组
//        byteBuffer.put("aaa".getBytes());
//        System.out.println(byteBuffer.position());//3
//        System.out.println(byteBuffer.limit());//10
//        System.out.println(byteBuffer.capacity());//10
//        position(int newPosition) 修改position
//        byteBuffer.position(1);
//        limit(int newLimit)   修改limit
//        byteBuffer.limit(5);
//        System.out.println(byteBuffer.position());
//        System.out.println(byteBuffer.limit());
//        System.out.println(byteBuffer.capacity());
//        int remaining()     还有多少能操作
//        boolean hasRemaining()    是否还有能操作的
        byteBuffer.put("0123456789".getBytes());
        System.out.println(byteBuffer.remaining());
        System.out.println(byteBuffer.hasRemaining());
    }
}

public class ByteBufferDemo3 {
    public static void main(String[] args) {
        ByteBuffer byteBuffer = ByteBuffer.allocate(10);
        byteBuffer.put("abc".getBytes());
//        flip()  切换读写模式（写读）
        byteBuffer.flip();
//        get()   读一个字节
//        while(byteBuffer.limit() != byteBuffer.position()){
//            System.out.println((char) byteBuffer.get());
//        }
        for (int i = 0; i < byteBuffer.limit(); i++) {
            System.out.println((char) byteBuffer.get());
        }
//        get(byte[] dst) 读多个字节
//        byte [] bytes = new byte[byteBuffer.limit()];
//        byteBuffer.get(bytes);
//        System.out.println(new String(bytes));
//        get(int index)  读指定索引的字节
//        System.out.println((char) byteBuffer.get(0));
//        rewind()    将position设置为0，可以重复读
//        byteBuffer.rewind();
//        for (int i = 0; i < byteBuffer.limit(); i++) {
//            System.out.println((char) byteBuffer.get());
//        }
//        clear()     数据读写完毕（读->写）
        byteBuffer.clear();
        byteBuffer.put("qqq".getBytes());
//        array()     将缓冲区转换成字节数组返回
        byte[] bytes = byteBuffer.array();
        System.out.println(new String(bytes));
    }
}