不同contentType的数据类型

Love The Way You Lie 2022-09-05 14:58 205阅读 0赞

## Server代码 ##

package com.test.tomcat.servlet;
    
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.net.SocketAddress;
    
    public class Server { 
    
        /** * 初始化服务器 * * @param host * @param port */
        public void init(String host, int port) { 
            try { 
                ServerSocket serverSocket = new ServerSocket();
                System.out.println("服务器 " + host + ":" + port + " 启动成功...");
                SocketAddress socketAddress = new InetSocketAddress(host, port);
                serverSocket.bind(socketAddress);
                readyAccept(serverSocket);
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }
    
        /** * 接收请求 * * @param serverSocket * @throws IOException */
        public void readyAccept(ServerSocket serverSocket) throws IOException { 
            while (true) { 
                Socket client = serverSocket.accept();
                System.out.println();
                new HandlerThread(client);
            }
        }
    
        /** * 请求处理 */
        static class HandlerThread implements Runnable { 
            private Socket socket;
    
            public HandlerThread(Socket socket) { 
                this.socket = socket;
                new Thread(this).start();
            }
    
            @Override
            public void run() { 
                try { 
                    showRequestData(socket);
                    writeResponseData(socket);
                } catch (Exception e) { 
                    e.printStackTrace();
                } finally { 
                    if (socket != null) { 
                        try { 
                            socket.close();
                            System.out.println("socket closed...");
                        } catch (Exception e) { 
                            socket = null;
                            System.out.println("socket close failed:" + e.getMessage());
                        }
                    }
                }
            }
    
            /** * 不能使用BufferedReader读取数据，因为会有数据读不全，导致读取数据一直阻塞 * 错误代码： * BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream())); * String line; * while ((line = br.readLine()) != null) { * System.out.println(line); * } * * @param socket * @throws Exception */
            public void showRequestData(Socket socket) throws Exception { 
                DataInputStream input = new DataInputStream(socket.getInputStream());
                byte[] bytes = new byte[input.available()];
                input.read(bytes);
                System.out.println(new String(bytes));
            }
    
            public void writeResponseData(Socket socket) throws IOException { 
                DataOutputStream out = new DataOutputStream(socket.getOutputStream());
                StringBuilder sb = new StringBuilder();
                sb.append("HTTP/1.1 200 ok").append("\r\n").append("Content-Type: application/json").append("\r\n").append("\r\n").append("{\"code\":200}");
                out.write(sb.toString().getBytes("UTF8"));
            }
        }
        public static void main(String[] args) { 
            Server server = new Server();
            server.init("localhost", 8081);
        }
    }

## 数据 ##

### application/x-www-form-urlencoded ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMwMDM4MTEx_size_16_color_FFFFFF_t_70]

### multipart/form-data ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMwMDM4MTEx_size_16_color_FFFFFF_t_70 1]

### application/json ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMwMDM4MTEx_size_16_color_FFFFFF_t_70 2]

## 遇到的问题 ##

一下情况都是以postman作为客户端模拟请求的！

### 获取请求数据的代码不同会导致不同的结果 ###

1.  InputStream\#read(byte b\[\]) +while循环发生阻塞问题

public void showRequestData(Socket socket) throws Exception { 
    
        byte[] bytes = new byte[1024];
        int len;
        InputStream inputStream = socket.getInputStream();
        while ((len = inputStream.read(bytes)) != -1) { 
            String s = new String(bytes, 0, len);
            System.out.println(s);
        }
    }

此代码循环完请求数据后，由于postman没有断开链接，会一直阻塞在while ((len = inputStream.read(bytes)) != -1)代码块这，并且通过idea的Evaluate Expression计算不出值，会一直阻塞。此时如果在postman上取消请求，这样才会跳出while循环。

1.  BufferedReader\#readLine发生阻塞问题

BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    String line;
    while ((line = br.readLine()) != null) { 
        System.out.println(line);
    }

此代码与上面的代码时一个效果  
3. 使用DataInputStream可以解决阻塞的问题

DataInputStream input = new DataInputStream(socket.getInputStream());
    byte[] bytes = new byte[input.available()];
    input.read(bytes);
    System.out.println(new String(bytes));

## 总结 ##

1.  HTTP/1.1这一行上面都有一行空行
2.  Content-length下一行是空行，再下一行是数据

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMwMDM4MTEx_size_16_color_FFFFFF_t_70 2]: /images/20220829/3aa0b324ca6c46b2b70b3ee249a9a7d1.png