执行UserServlet和CategoryServlet，会执行baseServlet重写的service方法，在service方法里面进行方法的分发，通过反射获取类的字节码文件，通过获取请求路径获取方法名，找到方法并且执行
package cn.itcast.travel.web.servlet;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class baseServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//System.out.println("baseServlet的service方法被执行了...");
//完成方法分发
//1.获取请求路径
String uri = req.getRequestURI(); // /travel/user/add
System.out.println("请求uri:"+uri);// /travel/user/add
//2.获取方法名称
String methodName = uri.substring(uri.lastIndexOf('/') + 1);
System.out.println("方法名称："+methodName);
//3.获取方法对象Method
//谁调用我？我代表谁
System.out.println(this);//UserServlet的对象cn.itcast.travel.web.servlet.UserServlet@4903d97e
try {
//获取方法,getMethod只能获取public方法
Method method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
//4.执行方法
//暴力反射
//method.setAccessible(true);
method.invoke(this,req,resp);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
package cn.itcast.travel.web.servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
@WebServlet("/category/*")
public class CategoryServlet extends baseServlet {
public void find(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("CategoryServlet的find方法被执行了");
}
public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("CategoryServlet的add方法被执行了");
}
}
package cn.itcast.travel.web.servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
@WebServlet("/user/*")
public class UserServlet extends baseServlet {
public void find(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("UserServlet的find方法被执行了");
}
public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("UserServlet的add方法被执行了");
}
}
