工具类--BaseServlet

工具类–BaseServlet

1、代码

public class BaseServlet extends HttpServlet {
	@Override
	public void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

		// localhost:8080/store/productServlet?method=addProduct
		String method = req.getParameter("method");

		if (null == method || "".equals(method) || method.trim().equals("")) {
			method = "execute";
		}

		// 注意:此处的this代表的是子类的对象
		// System.out.println(this);
		// 子类对象字节码对象
		Class clazz = this.getClass();

		try {
			// 查找子类对象对应的字节码中的名称为method的方法.这个方法的参数类型是:HttpServletRequest.class,HttpServletResponse.class
			Method md = clazz.getMethod(method, HttpServletRequest.class, HttpServletResponse.class);
			if(null!=md){
				String jspPath = (String) md.invoke(this, req, resp);
				if (null != jspPath) {
					req.getRequestDispatcher(jspPath).forward(req, resp);
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	// 默认方法
	public String execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		return null;
	}

2、逻辑
(1)获取请求参数method，确定具体需要执行的方法名
(2)获取当前运行类需要执行的方法Method
(3)执行当前运行类对应的方法
(4)通过方法返回值确定请求转发jsp位置

3、注意
(1)web.xml配置
(2)通过servlet转发给对应的实现类，输出进行测试