Java小白第一次就能看懂的网络编程

 实现TCP的网络编程 例子1：客户端发送信息给服务端，服务端将数据显示在控制台上 public class TCPTest1 { //客户端 @Test public void client() { Socket socket = null; OutputStream os = null; try { //1.创建Socket对象，指明服务器端的ip和端口号 InetAddress inet = InetAddress.getByName("127.0.0.1"); socket = new Socket(inet, 8899); //2.获取一个输出流，用于输出数据 os = socket.getOutputStream(); //3.写出数据的操作 os.write("你好，我是客户端mm".getBytes()); } catch (IOException e) { e.printStackTrace(); } finally { //4.资源的关闭 if(os != null){ try { os.close(); } catch (IOException e) { e.printStackTrace(); } } if(socket != null){ try { socket.close(); } catch (IOException e) { e.printStackTrace(); } } } } //服务端 @Test public void server(){ ServerSocket ss = null; Socket socket = null; InputStream is = null; ByteArrayOutputStream baos = null; try { //1.创建服务器的ServerSocket,指明自己的端口号 ss = new ServerSocket(8899); //2.调用accept()表示接收来自于客户端的socket socket = ss.accept(); //3.获取输入流 is = socket.getInputStream(); //不建议这样写，可能会有乱码 //        byte[] buffer = new byte[1024]; //        int len; //        while((len = is.read(buffer)) != -1){ //            String str = new String(buffer,0,len); //            System.out.println(str); //        } //4.读取输入流中的数据 baos = new ByteArrayOutputStream(); byte[] buffer = new byte[5]; int len; while((len = is.read(buffer)) != -1){ baos.write(buffer,0,len); } System.out.println(baos.toString()); } catch (IOException e) { e.printStackTrace(); } finally { //5.关闭资源 if(baos != null){ try { baos.close(); } catch (IOException e) { e.printStackTrace(); } } if(is != null){ try { is.close(); } catch (IOException e) { e.printStackTrace(); } } if(socket != null){ try { socket.close(); } catch (IOException e) { e.printStackTrace(); } } if(ss != null){ try { ss.close(); } catch (IOException e) { e.printStackTrace(); } } } } }

 实现TCP的网络编程 例题2：客户端发送文件给服务端，服务端将文件保存在本地。 public class TCPTest2 { //这里异常处理的方式应该使用try-catch-finally @Test public void client() throws IOException { Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), 9090); OutputStream os = socket.getOutputStream(); FileInputStream fis = new FileInputStream(new File("beauty.jpg-600")); byte[] buffer = new byte[1024]; int len; while((len = fis.read(buffer)) != -1){ os.write(buffer,0,len); } fis.close(); os.close(); socket.close(); } //这里异常处理的方式应该使用try-catch-finally @Test public void server() throws IOException { ServerSocket ss = new ServerSocket(9090); Socket socket = ss.accept(); InputStream is = socket.getInputStream(); FileOutputStream fos = new FileOutputStream(new File("beauty1.jpg-600")); byte[] buffer = new byte[1024]; int len; while((len = is.read(buffer)) != -1){ fos.write(buffer,0,len); } fos.close(); is.close(); socket.close(); ss.close(); } }

 实现TCP的网络编程 例题3：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 TCPTest3 { @Test public void client() throws IOException { Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), 9090); OutputStream os = socket.getOutputStream(); FileInputStream fis = new FileInputStream(new File("beauty.jpg-600")); byte[] buffer = new byte[1024]; int len; while((len = fis.read(buffer)) != -1){ os.write(buffer,0,len); } //服务区端给予客户端反馈 OutputStream os1 = socket.getOutputStream(); os.write("你好，美女，照片我以收到，非常漂亮！".getBytes()); fis.close(); os.close(); socket.close(); os1.close(); } //这里异常处理的方式应该使用try-catch-finally @Test public void server() throws IOException { ServerSocket ss = new ServerSocket(9090); Socket socket = ss.accept(); InputStream is = socket.getInputStream(); FileOutputStream fos = new FileOutputStream(new File("beauty2.jpg-600")); byte[] buffer = new byte[1024]; int len; while((len = is.read(buffer)) != -1){ fos.write(buffer,0,len); } //接受来自于服务器端的数据，并显示到控制台上 InputStream is1 = socket.getInputStream(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] bufferr = new byte[20]; int len1; while((len1 = is1.read(buffer)) != -1){ baos.write(buffer,0,len1); } System.out.println(baos.toString()); fos.close(); is.close(); socket.close(); ss.close(); baos.close(); } }

 UDP协议的网络编程 public class UDPTest { @Test public void sender() throws IOException { DatagramSocket socket = new DatagramSocket(); String str = "我是UDP方式发送的导弹"; byte[] data = str.getBytes(); InetAddress inet = InetAddress.getLocalHost(); DatagramPacket packet = new DatagramPacket(data,0,data.length,inet,9090); socket.send(packet); socket.close(); } @Test public void receiver() throws IOException { DatagramSocket socket = new DatagramSocket(9090); byte[] buffer = new byte[100]; DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length); socket.receive(packet); System.out.println(new String(packet.getData(),0,packet.getLength())); }

 URL网络编程 1.URL:统一资源定位符，对应着互联网的某一资源地址 2.格式： http://localhost:8080/examples/beauty.jpg-600?username=Tom 协议   主机名     端口号    资源地址       参数列表 public class URLTest { public static void main(String[] args) { try { URL url = new URL("http://localhost:8080/examples/beauty.jpg-600?username=Tom"); //            public String getProtocol()       获取该URL的协议名 System.out.println(url.getProtocol());// http //            public String getHost()           获取该URL的主机名 System.out.println(url.getHost());//localhost //            public String getPort()           获取该URL的端口号 System.out.println(url.getPort());// 8080 //            public String getPath()           获取该URL的文件路径 System.out.println(url.getPath());//examples/beauty.jpg-600 //            public String getFile()           获取该URL的文件名 System.out.println(url.getFile());//examples/beauty.jpg-600?username=Tom //            public String getQuery()          获取该URL的查询名 System.out.println(url.getQuery());//username=Tom } catch (MalformedURLException e) { e.printStackTrace(); } } }