Servle利用反射制作工具类tBaseServlet

深藏阁楼爱情的钟 2022-02-14 06:59 278阅读 0赞

package com.offcn.util;
    
    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 abstract class BaseServlet extends HttpServlet{
    
    	private static final long serialVersionUID = 1L;
    
    	public void service(HttpServletRequest req, HttpServletResponse resp)
                throws ServletException, IOException{
    
                // 获取参数, 用来识别用户想请求的方法
                String mark = req.getParameter("mark");
    
                // 判断该参数是否存在, 不存在,抛出异常
                if(mark == null || mark.trim().isEmpty()){
                    throw new RuntimeException("您没有传递 mark 参数! 无法确定您想调用的方法");
                }
    
                //得到当前类的 class 对象
                Class<? extends BaseServlet> c = this.getClass();
    
                //通过查找本类这子类中的方法名称（不是get和set是值类中的方法）
                Method method = null;
                try{
                    method = c.getMethod(mark,HttpServletRequest.class, HttpServletResponse.class);
                } catch(Exception e){
                    throw new RuntimeException("您要调用的方法"+mark+",它不存在!");
                }
    
                //如果发现类中有这个方法通过反射调用那个对应的方法
                try{
                    method.invoke(this,req,resp);  
                } catch(Exception e){                    
                    throw new RuntimeException(e);
                }
        }
    }

public class UserServlet extends BaseServlet{
    	//Servlet直接继承BaseServlet 可以省去判断
    	public void validate_phone(HttpServletRequest request, HttpServletResponse response) throws IOException {
    		
    		String phone_number = request.getParameter("phone_number");
    		boolean b = us.validate_phone(phone_number);
    		PrintWriter pw = response.getWriter();
    		pw.print(b+"");
    	}