将Servlet模块化的利器---反射抽取

BaseServlet为某个Servlet模块需要继承的对象

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;

@SuppressWarnings("all")
public class BaseServlet extends HttpServlet {
	 
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		
		req.setCharacterEncoding("UTF-8");
		
		try {
			//1、获得请求的method的名称
			String methodName = req.getParameter("method");
			//2、获得当前被访问的对象的字节码对象
			Class clazz = this.getClass();//ProductServlet.class ---- UserServlet.class
			//3、获得当前字节码对象的中的指定方法
			Method method = clazz.getMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
			//4、执行相应功能方法
			method.invoke(this, req,resp);
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}
 
}

那么，可以将Servlet写在一起，指定某个方法名即可代替原来的Servlet，避免过多的Servlet出现

public class ProductServlet extends BaseServlet {

	public void findAllCategory(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException, SQLException {
		
		//代码
	}
        

}在请求servlet时，只需要传递一个method参数即可调用相应的servlet方法了！