访问网址时的请求，请求的内容就大概是这个样子了，那么这个时候要表示这个请求。
package tomcat; import java.io.IOException; import java.io.InputStream; /** * @Author lyr * @create 2020/7/15 21:34 */ public class IRequest { private String url; public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public String getMethod() { return method; } public void setMethod(String method) { this.method = method; } private String method; public IRequest(InputStream inputStream) throws IOException { String request = ""; byte[] bytes = new byte[1024]; int len = 0; if((len = inputStream.read(bytes))>0) { request = new String(bytes,0,len); } System.out.println("request Body :-> \r\n"+request); String httpHead = request.split("\n")[0]; url = httpHead.split("\\s")[1]; method = httpHead.split("\\s")[0]; System.out.println(this); } }
package tomcat; import java.io.IOException; import java.io.OutputStream; /** * @Author lyr * @create 2020/7/15 21:46 */ public class IResponse { private OutputStream outputStream; public IResponse(OutputStream outputStream) { this.outputStream = outputStream; } public void write(String content) throws IOException { StringBuilder sb = new StringBuilder(); sb.append("HTTP/1.1 200 OK\n") .append("Content-Type: text/html\n") .append("\r\n") .append("<html><body>") .append(content) .append("</body></html>"); outputStream.write(sb.toString().getBytes()); outputStream.close(); } }
简单定义 Servlet接口
package tomcat; /** * @Author lyr * @create 2020/7/15 21:51 */ public abstract class IServlet { /** * @param request * @param response */ public abstract void doGet(IRequest request,IResponse response); /** * @param request * @param response */ public abstract void doPost(IRequest request,IResponse response); public void service(IRequest request,IResponse response) { if(request.getMethod().equalsIgnoreCase("POST")) { doPost(request,response); }else if(request.getMethod().equalsIgnoreCase("GET")) { doGet(request,response); } } }
实现代码：
package tomcat.impl; import tomcat.IRequest; import tomcat.IResponse; import tomcat.IServlet; import java.io.IOException; /** * @Author lyr * @create 2020/7/15 21:56 */ public class HelloServletImpl extends IServlet { /** * @param request * @param response */ @Override public void doGet(IRequest request, IResponse response) { try { response.write("hello world"); } catch (IOException e) { e.printStackTrace(); } } /** * @param request * @param response */ @Override public void doPost(IRequest request, IResponse response) { try { response.write(" hello post "); } catch (IOException e) { e.printStackTrace(); } } }
然后把 URL 和 解析的 Servlet绑定到一起。
package tomcat; /** * @Author lyr * @create 2020/7/15 21:59 */ public class ServletMapping { private String servletName; private String url; private Class<?> clazz; public ServletMapping(String servletName, String url, Class<?> clazz) { this.servletName = servletName; this.url = url; this.clazz = clazz; } public String getServletName() { return servletName; } public void setServletName(String servletName) { this.servletName = servletName; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public Class<?> getClazz() { return clazz; } public void setClazz(Class<?> clazz) { this.clazz = clazz; } }
package tomcat; import tomcat.impl.HelloServletImpl; import java.util.ArrayList; import java.util.List; /** * @Author lyr * @create 2020/7/15 22:01 */ public class ServletMappingConfig { public static List<ServletMapping> servletMappingList = new ArrayList<>(); static { servletMappingList.add(new ServletMapping("helloServlet","/hello", HelloServletImpl.class)); servletMappingList.add(new ServletMapping("helloServlet","/aa",HelloServletImpl.class)); } }
监听端口，然后运行程序
package tomcat; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; import java.util.HashMap; import java.util.Map; /** * @Author lyr * @create 2020/7/15 22:03 */ public class TomcatServer { private int port = 8080; private Map<String,Class<?>> urlServletMap = new HashMap<>(); public TomcatServer(int port) { this.port = port; } public void start() { initServletMapping(); ServerSocket serverSocket = null; try { serverSocket = new ServerSocket(port); System.out.println("tomcat is running"); while (true) { Socket socket = serverSocket.accept(); InputStream is = socket.getInputStream(); OutputStream os = socket.getOutputStream(); dispatch(new IRequest(is),new IResponse(os)); socket.close(); } } catch (IOException e) { e.printStackTrace(); } } private void initServletMapping() { for(ServletMapping s: ServletMappingConfig.servletMappingList) { urlServletMap.put(s.getUrl(),s.getClazz()); } } private void dispatch(IRequest request,IResponse response) { Class<?> clazz = urlServletMap.get(request.getUrl()); System.out.println(clazz); try { // Class<IServlet> servletClazz = (Class<IServlet>)clazz; if(clazz!=null) { IServlet servlet = (IServlet) clazz.newInstance(); servlet.service(request,response); } } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InstantiationException e) { e.printStackTrace(); } } public static void main(String[] args) { new TomcatServer(8081).start(); } }
浏览器请求的内容就是这些了
