HttpServer

• 現在我們的Connector類比較繁瑣不簡潔，因為它既要接收請求，又要處理請求，現在專門用一個類HttpServer來接管請求處理這一部分功能。

HttpServer類

• 接管處理部分，所以要有handle200(), handle404(),handle500()函式等等。

• package jerrymice.catalina;
  
  import cn.hutool.core.io.FileUtil;
  import cn.hutool.core.util.ArrayUtil;
  import cn.hutool.core.util.StrUtil;
  import cn.hutool.log.LogFactory;
  import jerrymice.http.Request;
  import jerrymice.http.Response;
  import jerrymice.util.Constant;
  import jerrymice.util.WebXmlUtil;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.net.Socket;
  
  /**
   * @author ：xsliu
   * @date ：Created in 2020/8/18 17:18
   * @description：接管Connector類中對請求的處理部分
   * @modified By：
   */
  public class HttpServer {
      public void execute(Socket socket, Request request, Response response){
          // 處理請求和響應
          try{
              String uri = request.getUri();
              if (uri == null) {
                  // 說明此時沒有請求過來
                  return;
              }
              Context context = request.getContext();
              if ("/500.html".equals(uri)) {
                  throw new Exception("this is a deliberately created ");
              }
              if ("/".equals(uri)){
                  //如果訪問根目錄
                  uri = WebXmlUtil.getWelcomeFile(request.getContext());
              }
              String fileName = StrUtil.removePrefix(uri, "/");
              // 獲取檔名
              File file = FileUtil.file(context.getDocBase(), fileName);
              // 通過context獲取資料夾，然後通過資料夾和檔名來獲取檔案
              if (file.exists()){
                  // 如果訪問的檔案存在，就根據這個獲取字尾名
                  String extName = FileUtil.extName(file);
                  // 根據字尾名獲取瀏覽器解析該檔案時使用的mimeType
                  String mimeType = WebXmlUtil.getMimeType(extName);
                  response.setContentType(mimeType);
              }
              else{
                  //檔案不存在，返回404錯誤
                  handle404(socket, uri);
                 return;
              }
              handle200(socket, response);
          }catch (Exception e) {
              LogFactory.get().info(e.toString());
              handle500(socket, e);
          }finally {
              try{
                  if (!socket.isClosed()){
                      socket.close();
                  }
              }catch (IOException e){
                  LogFactory.get().info(e.toString());
              }
          }
      }
  
      /**
       * 處理檔案不存在異常
       */
      private void handle404(Socket socket, String uri) throws IOException {
          OutputStream outputStream = socket.getOutputStream();
          String responseText = StrUtil.format(Constant.textFormat404, uri, uri);
          responseText = Constant.responseHead404 + responseText;
          byte[] responseBytes = responseText.getBytes("utf-8");
          outputStream.write(responseBytes);
      }
  
      /**
       * 處理正常響應
       */
  
      private void handle200(Socket socket, Response response) throws IOException{
          String contentType = response.getContentType();
          String headText = Constant.responseHead200;
          byte[] head = headText.getBytes();
          byte[] body = response.getBody();
          byte[] responseBytes = new byte[head.length + body.length];
          ArrayUtil.copy(head, 0, responseBytes, 0, head.length);
          ArrayUtil.copy(body, 0, responseBytes, head.length, body.length);
  
          OutputStream outputStream = socket.getOutputStream();
          outputStream.write(responseBytes);
      }
  
      /**
       * 處理訪問時出現的問題
       * @param socket: 訪問通訊過程中所使用的socket
       * @param e: 異常
       */
      private void handle500(Socket socket, Exception e){
          try{
              OutputStream outputStream = socket.getOutputStream();
              StackTraceElement[]  stackTraceElements = e.getStackTrace();
              StringBuffer stringBuffer = new StringBuffer();
              stringBuffer.append(e.toString());
              stringBuffer.append("\r\n");
              for (StackTraceElement element : stackTraceElements) {
                  stringBuffer.append("\t");
                  stringBuffer.append(element.toString());
                  stringBuffer.append("\r\n");
              }
              String msg = e.getMessage();
              if (null != msg && msg.length() > 20){
                  msg = msg.substring(0, 19);
              }
  
              String text = StrUtil.format(Constant.textFormat500, msg, e.toString(), stringBuffer.toString());
              text = Constant.responseHead500 + text;
              byte[] responseBytes = text.getBytes("utf-8");
              outputStream.write(responseBytes);
          }catch(IOException e1){
              LogFactory.get().info(e1.toString());
          }
      }
  }
  
   
  

Connector類

• Connector類中的處理部分可以去掉了，只負責接收請求。

• package jerrymice.catalina;
  
  import cn.hutool.core.io.FileUtil;
  import cn.hutool.core.util.ArrayUtil;
  import cn.hutool.core.util.StrUtil;
  import cn.hutool.log.LogFactory;
  import com.sun.org.apache.bcel.internal.ExceptionConst;
  import jerrymice.http.Request;
  import jerrymice.http.Response;
  import jerrymice.util.Constant;
  import jerrymice.util.ThreadUtil;
  import jerrymice.util.WebXmlUtil;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.nio.charset.StandardCharsets;
  
  /**
   * @author xsl20
   */
  public class Connector implements Runnable{
  
      int port;
      private Service service;
  
      public Service getService(){
          return service;
      }
      public void setPort(int port){
          this.port = port;
      }
      public Connector(Service service){
          this.service = service;
      }
  
      public void init(){
          LogFactory.get().info("Initializing Protocol [http-bio-{}], port");
      }
  
      public void start(){
          LogFactory.get().info("Starting ProtocolHandler [http-bio-{}],port");
          new Thread(this).start();
      }
  
      @Override
      public void run() {
          try{
              ServerSocket serverSocket = new ServerSocket(port);
              while(true) {
                  Socket socket = serverSocket.accept();
                  Runnable r = () -> {
                      try {
                          Request request = new Request(socket, service);
                          Response response = new Response();
                          HttpServer httpServer = new HttpServer();
                          httpServer.execute(socket, request, response);
                      }catch (Exception e){
                          LogFactory.get().info(e.toString());
                      }finally {
                          // 將socket的關閉提取到最後
                          try{
                              socket.close();
                          }catch(IOException e){
                              LogFactory.get().info(e);
                          }
                      }
                  };
                  ThreadUtil.run(r);
              }
          }catch (IOException e) {
              LogFactory.get().info(e);
          }
      }
  }
   
  

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