JAVA重寫servlet實現地址欄參數訪問

原創

2020-02-22 05:37

大致功能是類似IndexServlet等Servlet方法去掉doGet,doPost地址欄通過?action=??實現訪問具體方法

思路：編寫AbstractServlet實現此功能，其他Servlet繼承此類

package com.servlet;

import java.io.IOException;
import java.lang.reflect.Method;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class AbstractServlet extends HttpServlet {

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//1 當前是哪個Servlet類
		Class<?> clazz=this.getClass();
		//System.out.println(clazz);
		//2、獲取到Servlet類中要執行的方法名
		String methodName=req.getParameter("action");
		//System.out.println("方法名:"+methodName);
		//3、執行方法(反射)
		
		try {
			//創建一個類對象
			Object obj=clazz.newInstance();
			//根據方法名稱獲取指定的方法
			Method m=clazz.getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
			//調用方法
			m.invoke(obj, req,resp);
			
		} catch (Exception e) {
			
			e.printStackTrace();
		} 
	}

}

package com.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class IndexServlet
 */
@WebServlet("/IndexServlet")
public class IndexServlet extends AbstractServlet {
    private static final long serialVersionUID = 1L;

    public IndexServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    public void index(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.sendRedirect("index.jsp");	
    }
    
    public void list(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.sendRedirect("list.jsp");	
    }

    public void login(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.sendRedirect("login.jsp");	
    }
    public void add(HttpServletRequest request, HttpServletResponse response) {
        //
    }

}