---java 网络编程总结

InetAddress

/*
 * inetAddress代表ip地址
 * 创建Inetaddress对象：getByName(String name)
 * getHostName():获取域名
 * getHostAddress:获取IP地址
 */
public class TestInetAddress {
    @Test
    public void test() throws Exception {
        // 创建一个Inetaddress对象
        InetAddress ia = InetAddress.getByName("www.baidu.com");
        System.out.println(ia); // www.baidu.cm/61.135.169.125
        // InetAddress ia2 = InetAddress.getByName("61.135.169.125");
        // System.out.println(ia2);/// 61.135.169.125

        System.out.println(ia.getHostName());// www.baidu.com
        System.out.println(ia.getHostAddress());// 61.135.169.125

        // 获取本机ip：getlocalhost
        InetAddress ia3 = InetAddress.getLocalHost();
        System.out.println(ia3);// tuxianchao_PC/192.168.1.105
        System.out.println(ia3.getHostName());// tuxianchao_PC
        System.out.println(ia3.getHostAddress());// 192.168.1.105

    }
}

tcp

/*
 *  
 * TCP编程例一：客户端给服务端发送信息。服务端输出此信息到控制台上
 * 网络编程实际上就是Socket的编程
 */
public class TestTCP1 {
    @Test
    public void Client() {
        Socket socket = null;
        OutputStream os = null;
        try {
            // 1.创建一个Socket的对象，通过构造器指明服务端的IP地址，以及其接收程序的端口号
            socket = new Socket("127.0.0.1", 9090);
            // 2.getOutputStream()：发送数据，方法返回OutputStream的对象
            os = socket.getOutputStream();
            // 3.具体的输出过程
            os.write("我是客户端".getBytes());
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 4.关闭相应的流和Socket对象
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    @Test
    public void Server() {

        // 1.创建一个ServerSocket的对象，通过构造器指明自身的端口号
        ServerSocket ss = null;
        // 2.调用其accept()方法，返回一个Socket的对象
        Socket s = null;
        // 3.调用Socket对象的getInputStream()获取一个从客户端发送过来的输入流
        InputStream is = null;
        try {
            ss = new ServerSocket(9090);
            System.out.println("服务端已经启动");
            s = ss.accept();
            is = s.getInputStream();
            // 4.对获取的输入流进行的操作
            System.out.print("客户端发来：");
            byte[] b = new byte[20];
            int len;
            while ((len = is.read(b)) != -1) {
                String str = new String(b, 0, len);
                System.out.print(str);
            }
            System.out.println();
            System.out.println(
                    "收到：" + s.getInetAddress().getHostName() + "    " + s.getInetAddress().getHostAddress() + "的连接");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 5.关闭相应的流以及Socket、ServerSocket的对象
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (ss != null) {
                try {
                    ss.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

/*
 *  
 * TCP编程例二
 */
public class TestTCP2 {
    @Test
    public void Client() {
        Socket s = null;
        OutputStream os = null;
        InputStream is = null;
        try {
            s = new Socket("127.0.0.1", 9090);
            os = s.getOutputStream();
            os.write("我是客户端".getBytes());
            s.shutdownOutput();// 显示的告诉服务端发送完毕
            is = s.getInputStream();
            byte[] b = new byte[20];
            int len;
            while ((len = is.read(b)) != -1) {
                String str = new String(b, 0, len);
                System.out.print(str);
            }
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    @Test
    public void Server() {
        ServerSocket ss = null;
        Socket s = null;
        InputStream is = null;
        OutputStream os = null;
        try {
            ss = new ServerSocket(9090);
            System.out.println("服务端已经启动");
            s = ss.accept();
            is = s.getInputStream();
            byte[] b = new byte[20];
            int len;
            while ((len = is.read(b)) != -1) {
                String str = new String(b, 0, len);
                System.out.print(str);
            }
            os = s.getOutputStream();
            os.write("我已经收到客户端发来的消息".getBytes());
            s.shutdownOutput();// 显示的告诉客户端发送完毕

            System.out.println();
            System.out.println("收到：" + s.getInetAddress().getHostName() + s.getInetAddress().getHostAddress() + "的消息");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (is != null) {

                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (s != null) {

                try {
                    s.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (ss != null) {
                try {
                    ss.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
        }
    }
}

/*
 * TCP编程例三：从客户端发送文件给服务端，服务端保存到本地。
 * 并返回“发送成功”给客户端。并关闭相应的连接。
 */
public class TestTCP3 {
    @Test
    public void Client() {
        Socket s = null;
        OutputStream os = null;
        FileInputStream fis = null;
        InputStream is = null;
        try {
            // 1.创建Socket的对象
            s = new Socket("127.0.0.1", 9090);
            // 2.从本地获取一个文件发送给服务端
            os = s.getOutputStream();
            fis = new FileInputStream(new File("C:\\Users\\tuxianchao\\Desktop\\image.jpg"));
            byte[] b = new byte[1024];
            int len;
            while ((len = fis.read(b)) != -1) {
                os.write(b, 0, len);
            }
            s.shutdownOutput();
            // 3.接收来自于服务端的信息
            is = s.getInputStream();
            byte[] b1 = new byte[1024];
            int len1;
            while ((len1 = is.read(b1)) != -1) {
                String str = new String(b1, 0, len);
                System.out.print(str);
            }
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 4.关闭相应的流和Socket对象
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    @Test
    public void Server() {

        ServerSocket ss = null;

        Socket s = null;

        InputStream is = null;
        FileOutputStream fos = null;

        OutputStream os = null;
        try {
            // 1.创建ServerSocket对象
            ss = new ServerSocket(9090);
            System.out.println("服务端已经启动");
            // 2.创建Socket对象
            s = ss.accept();
            // 3.将从客户端发送来的信息保存到本地
            is = s.getInputStream();
            fos = new FileOutputStream(new File("C:\\Users\\tuxianchao\\Desktop\\image1.jpg"));
            byte[] b = new byte[1024];
            int len;
            while ((len = is.read(b)) != -1) {
                fos.write(b, 0, len);// 将文件写出到本地
            }

            System.out
                    .println("收到来自于：" + s.getInetAddress().getHostName() + s.getInetAddress().getHostAddress() + "的文件");
            System.out.println("文件已经写入本地");
            // 4.发送"接收成功"的信息反馈给客户端
            os = s.getOutputStream();
            os.write("已经收到文件".getBytes());

        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 5.关闭相应的流和Socket及ServerSocket的对象
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

        }
    }
}

udp

*
 * UDP编程实现发送消息
 * 
 * 
 */
public class TestUDP {
    @Test
    // 发送端
    public void Send() {
        DatagramSocket ds = null;
        try {
            // 创建一个DatagramSocket
            ds = new DatagramSocket();
            // 要发送的信息
            byte[] b = "这里是发送的数据".getBytes();
            // 创建一个数据报：每一个数据报不能大于64k，都记录着数据信息，
            // 将长度为 length 偏移量为 offset 的包发送到指定主机上的指定端口号。
            DatagramPacket packet = new DatagramPacket(b, 0, b.length, InetAddress.getByName("127.0.0.1"), 9090);

            // 发送数据报
            ds.send(packet);
            System.out.println("（发送端）发送完毕");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 关闭
            if (ds != null) {
                ds.close();
            }
        }
    }

    @Test
    public void Rceive() {

        DatagramSocket ds = null;

        try {
            // 创建DatagramSocket
            ds = new DatagramSocket(9090);
            // 接收数据的容器
            byte[] b = new byte[1024];
            // 创建DatagramPacket来接收数据
            DatagramPacket packet = new DatagramPacket(b, 0, b.length);

            // 接收数据报
            ds.receive(packet);
            System.out.println("(接收端)收到消息：");
            // 输出收到的信息
            String str = new String(packet.getData(), 0, packet.getLength());
            System.out.println("（接收端）" + str);
        } catch (SocketException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            // 关闭
            if (ds != null) {
                ds.close();
            }
        }
    }
}

url

/*
 * 
 * URL:统一资源定位符，一个URL的对象，对应着互联网上一个资源。
 * 可以通过URL的对象调用其相应的方法，将此资源读取（“下载”）
 * 
 * 
 *  
         * public String getProtocol( ) 获取该URL的协议名
         * 
         * public String getHost( ) 获取该URL的主机名
         * 
         * public String getPort( ) 获取该URL的端口号
         * 
         * public String getPath( ) 获取该URL的文件路径
         * 
         * public String getFile( ) 获取该URL的文件名
         * 
         * public String getRef( ) 获取该URL在文件中的相对位置
         * 
         * public String getQuery( ) 获取该URL的查询名
 */
public class TestURL {

    @Test
    public void Test() {

        InputStream is = null;
        URL mUrl = null;
        try {
            // 1.创建一个URL的对象
            mUrl = new URL("http://www.baidu.com");
            // 2.将服务端的资源读取进来:openStream()
            is = mUrl.openStream();
            byte[] b = new byte[1024];
            int len;
            while ((len = is.read(b)) != -1) {
                String str = new String(b, 0, len);
                System.out.println(str);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        // 如果既有数据的输入，又有数据的输出，则考虑使用URLConnection
        // 这里把获取到的数据写入到本地文件

        InputStream is1 = null;
        FileOutputStream fos = null;
        try {
            URLConnection urlConn = mUrl.openConnection();
            is1 = urlConn.getInputStream();
            fos = new FileOutputStream(new File("C:\\Users\\tuxianchao\\Desktop\\1.html"));
            byte[] b1 = new byte[1024];
            int len1;
            while ((len1 = is1.read(b1)) != -1) {
                fos.write(b1, 0, len1);
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (is1 != null) {
                try {
                    is1.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}