add readme

README.md

@@ -1 +1,209 @@
-Implemented a simplified version of Tomcat for learning purposes.
+![](IMG/Pasted%20image%2020241011225855.png)
+![](IMG/Pasted%20image%2020241011225913.png)
+![](IMG/Pasted%20image%2020241013113954.png)
+### 基础
+- MyHttpRequest
+    - `parse()`（解析流）
+    - `parseUri()`（请求的内容存储到uri）
+    - `getUri()`（返回uri）
+- MyHttpResponse
+    - `sendRedirect(String uri)`（判断资源是否存在，不存在返回404  ，存在返回目标资源）
+    - `getResponseMessage(String code, String message)`（构造响应消息）
+- MyHttpServer
+    - `start()`（循环接收浏览器请求，并且处理请求）
+- Test`
+    - `main()`（主方法测试类）
+
+###### MyHttpRequest
+```C#
+import java.io.IOException;
+import java.io.InputStream;
+
+public class MyHttpRequest {
+    private InputStream inputStream;
+    private String uri;
+
+    public MyHttpRequest(InputStream inputStream) {
+        this.inputStream = inputStream;
+    }
+
+    /**
+     * 解析流
+     */
+    public void parse(){
+        try {
+            byte[] bytes = new byte[1024];
+            inputStream.read(bytes);
+            String request = new String(bytes);
+            parseUri(request);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * 请求判断
+     */
+    public void parseUri(String request) {
+        int index1,index2;
+        index1 = request.indexOf(" ");//找空格下标
+        index2 = request.indexOf(" ",index1+1);//找空格下标2
+        uri = request.substring(index1+1,index2);//输出资源位置
+        System.out.println(uri);
+    }
+
+    public String getUri() {
+        return this.uri;
+    }
+}
+```
+
+###### MyHttpResponse
+```C#
+import java.io.*;
+
+public class MyHttpResponse {
+    private int statusCode;
+    private String statusMessage;
+
+    private OutputStream outputStream;
+
+    public MyHttpResponse(OutputStream outputStream){
+        this.outputStream = outputStream;
+    }
+
+    public void sendRedirect(String uri){
+        //判断资源是否存在
+        // 不存在返回404
+        // 存在返回目标资源
+        File file = new File(System.getProperty("user.dir")+"/WebContent" + uri);
+        if (file.exists()){
+            try {
+                FileInputStream fileInputStream = new FileInputStream(file);
+                byte[] bytes = new byte[(int)file.length()];
+                fileInputStream.read(bytes);
+                String result = new String(bytes);
+//                System.out.println(result);
+                String response = getResponseMessage("200,",result);
+                this.outputStream.write(response.getBytes());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+
+        }else {
+            try {
+                String error = getResponseMessage("404","404 File Not Found!");
+                this.outputStream.write(error.getBytes());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public String getResponseMessage(String code, String message){
+        return "HTTP/1.1 " + code + "\r\n" +
+                "Content-Type: text/html\r\n" +
+                "Content-Length: " + message.length() +
+                "\r\n" +
+                "\r\n" +
+                message;
+
+    }
+}
+```
+
+###### MyHttpServer
+```C#
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class MyHttpServer {
+    private int port = 8080;
+
+    public void receiving()
+    {
+        try{
+            //create socket service
+            ServerSocket serverSocket = new ServerSocket(port);
+            while(true){
+                //获取连接对象
+                Socket socket = serverSocket.accept();
+                //获取链接对象输入流
+                InputStream inputStream = socket.getInputStream();
+                //创建request
+                MyHttpRequest request = new MyHttpRequest(inputStream);
+                //解析请求
+                request.parse();
+                //创建响应
+                OutputStream outputStream = socket.getOutputStream();
+                MyHttpResponse response = new MyHttpResponse(outputStream);
+                //进行响应
+                response.sendRedirect(request.getUri());
+
+            }
+            //loop accept requests
+        }catch (Exception e){
+
+        }
+
+    }
+}
+```
+
+###### Test
+```C#
+public class Test {
+    public static void main(String[] args) {
+        System.out.println("server startup successfully");
+        MyHttpServer server = new MyHttpServer();
+        server.receiving();
+    }
+}
+```
+
+### 进阶
+![](IMG/Pasted%20image%2020241012213802.png)
+![](IMG/Pasted%20image%2020241012213832.png)
+
+Tomcat的两个重要身份：
+1. http服务器
+2. Tomcat是一个Servlet容器
+
+使用Servlet规范来实现Tomcat
+- AbstractHttpServletRequest *(implements HttpServletRequest)*
+- AbstractHttpServletResponse *(implements HttpServletResponse)*
+- ResponseServletOutputStream *(extends ServletOutputStream)*
+    - `write(int b)`
+    - `getBytes()`
+    - `getPos()`
+- MyHttpRequest *(extends AbstractHttpServletRequest)*
+    - `parse()`（解析流）
+    - `parseMessageLine()`（请求行解析）
+    - `getMethod()`（返回请求方式）
+    - `getRequestURL()`（返回请求地址，通常为**appName/Servlet** ）
+    - `getProtocol()`（返回协议）
+- MyHttpResponse *(extends AbstractHttpServletResponse)*
+    - `public MyHttpResponse(MyHttpRequest request, OutputStream outputStream)`（构造方法）
+    - `setStatus(int i, String s)`
+    - `getStatus()`
+    - `addHeader(String s, String s1)`
+    - `ResponseServletOutputStream getOutputStream()`（servlet的doGet所write的消息体）
+    - `complete()`（完成响应，调用下面三个方法）
+    - `sendResponseMsgLine()`
+    - `sendResponseMsgHeader()`
+    - `sendResponseMsgBody()`
+- Tomcat (添加线程池)
+    - `main(String[] args)`（启动Tomcat）
+    - `deployApps()`（利用反射部署指定目录下的应用）
+    - `start()`（循环接收浏览器请求，并且处理请求）
+    - `getAllFilePath()`（递归的获得项目内所有文件）
+    - `getContextMap()`（添加应用映射）
+- SocketProcessor *(implements Runnable)*
+    - `run()`（调用processSocket）
+    - `processSocket(Socket socket)`（处理请求）
+- Context
+    - `addUrlPatternMapping(String pattern, Servlet servlet)`（添加应用下Servlet映射）
+    - `getByUrlPatternMapping(String urlPattern)` （得到Servlet对象）
+- DefaultServlet *(extends HttpServlet)*

src/main/java/com.xiaoyi/MyHttpResponse.java

@@ -50,14 +50,14 @@ public class MyHttpResponse extends AbstractHttpServletResponse{
 //        }
 //    }
 
-    public String getResponseMessage(String code, String message){
+//    public String getResponseMessage(String code, String message){
-        return "HTTP/1.1 " + code + "\r\n" +
+//        return "HTTP/1.1 " + code + "\r\n" +
-                "Content-Type: text/html\r\n" +
+//                "Content-Type: text/html\r\n" +
-                "Content-Length: " + message.length() +
+//                "Content-Length: " + message.length() +
-                "\r\n" +
+//                "\r\n" +
-                "\r\n" +
+//                "\r\n" +
-                message;
+//                message;
-    }
+//    }
 
     @Override
     public void setStatus(int i, String s) {