Java之UDP,TCP的详细解析

练习四：文件名重复

public class UUIDTest { public static void main(String[] args) { String str = UUID.randomUUID().toString().replace("-", ""); System.out.println(str);//9f15b8c356c54f55bfcb0ee3023fce8a } } ```public class Client {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//1. 创建Socket对象，并连接服务器Socket socket = new Socket("127.0.0.1",10000);
​//2.读取本地文件中的数据，并写到服务器当中BufferedInputStream bis = new BufferedInputStream(new FileInputStream("mysocketnet\\clientdir\\a.jpg"));BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());byte[] bytes = new byte[1024];int len;while ((len = bis.read(bytes)) != -1){bos.write(bytes,0,len);}
​//往服务器写出结束标记socket.shutdownOutput();
​
​//3.接收服务器的回写数据BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));String line = br.readLine();System.out.println(line);
​
​//4.释放资源socket.close();
​}
}
public class Server {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//1.创建对象并绑定端口ServerSocket ss = new ServerSocket(10000);
​//2.等待客户端来连接Socket socket = ss.accept();
​//3.读取数据并保存到本地文件中BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());String name = UUID.randomUUID().toString().replace("-", "");BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("mysocketnet\\serverdir\\" + name + ".jpg"));int len;byte[] bytes = new byte[1024];while ((len = bis.read(bytes)) != -1) {bos.write(bytes, 0, len);}bos.close();//4.回写数据BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("上传成功");bw.newLine();bw.flush();
​//5.释放资源socket.close();ss.close();}
}

练习五：服务器改写为多线程

服务器只能处理一个客户端请求，接收完一个图片之后，服务器就关闭了。

优化方案一：

使用循环

弊端：

第一个用户正在上传数据，第二个用户就来访问了，此时第二个用户是无法成功上传的。

所以，使用多线程改进

优化方案二：

每来一个用户，就开启多线程处理

public class Client {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//1. 创建Socket对象，并连接服务器Socket socket = new Socket("127.0.0.1",10000);
​//2.读取本地文件中的数据，并写到服务器当中BufferedInputStream bis = new BufferedInputStream(new FileInputStream("mysocketnet\\clientdir\\a.jpg"));BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());byte[] bytes = new byte[1024];int len;while ((len = bis.read(bytes)) != -1){bos.write(bytes,0,len);}
​//往服务器写出结束标记socket.shutdownOutput();
​
​//3.接收服务器的回写数据BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));String line = br.readLine();System.out.println(line);
​
​//4.释放资源socket.close();
​}
}
public class Server {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//1.创建对象并绑定端口ServerSocket ss = new ServerSocket(10000);
​while (true) {//2.等待客户端来连接Socket socket = ss.accept();
​//开启一条线程//一个用户就对应服务端的一条线程new Thread(new MyRunnable(socket)).start();}
​}
}
​
​
public class MyRunnable implements Runnable{
​Socket socket;
​public MyRunnable(Socket socket){this.socket = socket;}
​@Overridepublic void run() {try {//3.读取数据并保存到本地文件中BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());String name = UUID.randomUUID().toString().replace("-", "");BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("mysocketnet\\serverdir\\" + name + ".jpg"));int len;byte[] bytes = new byte[1024];while ((len = bis.read(bytes)) != -1) {bos.write(bytes, 0, len);}bos.close();//4.回写数据BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("上传成功");bw.newLine();bw.flush();} catch (IOException e) {e.printStackTrace();} finally {//5.释放资源if(socket != null){try {socket.close();} catch (IOException e) {e.printStackTrace();}}}}
}

练习六：线程池改进

public class Client {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//1. 创建Socket对象，并连接服务器Socket socket = new Socket("127.0.0.1",10000);
​//2.读取本地文件中的数据，并写到服务器当中BufferedInputStream bis = new BufferedInputStream(new FileInputStream("mysocketnet\\clientdir\\a.jpg"));BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());byte[] bytes = new byte[1024];int len;while ((len = bis.read(bytes)) != -1){bos.write(bytes,0,len);}
​//往服务器写出结束标记socket.shutdownOutput();
​
​//3.接收服务器的回写数据BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));String line = br.readLine();System.out.println(line);
​
​//4.释放资源socket.close();
​}
}
public class Server {public static void main(String[] args) throws IOException {//客户端：将本地文件上传到服务器。接收服务器的反馈。//服务器：接收客户端上传的文件，上传完毕之后给出反馈。
​
​//创建线程池对象ThreadPoolExecutor pool = new ThreadPoolExecutor(3,//核心线程数量16,//线程池总大小60,//空闲时间TimeUnit.SECONDS,//空闲时间（单位）new ArrayBlockingQueue<>(2),//队列Executors.defaultThreadFactory(),//线程工厂，让线程池如何创建线程对象new ThreadPoolExecutor.AbortPolicy()//阻塞队列);
​
​
​//1.创建对象并绑定端口ServerSocket ss = new ServerSocket(10000);
​while (true) {//2.等待客户端来连接Socket socket = ss.accept();
​//开启一条线程//一个用户就对应服务端的一条线程//new Thread(new MyRunnable(socket)).start();pool.submit(new MyRunnable(socket));}
​}
}
public class MyRunnable implements Runnable{
​Socket socket;
​public MyRunnable(Socket socket){this.socket = socket;}
​@Overridepublic void run() {try {//3.读取数据并保存到本地文件中BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());String name = UUID.randomUUID().toString().replace("-", "");BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("mysocketnet\\serverdir\\" + name + ".jpg"));int len;byte[] bytes = new byte[1024];while ((len = bis.read(bytes)) != -1) {bos.write(bytes, 0, len);}bos.close();//4.回写数据BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));bw.write("上传成功");bw.newLine();bw.flush();} catch (IOException e) {e.printStackTrace();} finally {//5.释放资源if(socket != null){try {socket.close();} catch (IOException e) {e.printStackTrace();}}}}
}