servlet的三种实现方式

继承 HttpServlet（此方式较常使用）

public class Test01 extends GenericServlet {
	//GenericServlet继承了servlet接口
	@Override
	public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("test01提供服务");
	}
	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("test01初始化");
	}
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("test01销毁");
	}
}

继承GenericServlet

public class Test02 extends HttpServlet {
	@Override
	protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("test02提供服务了");
	}
	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("test02初始化了");
	}
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("test02销毁了");
	}
}

继承接口Servlet

public  class Test03 implements Servlet {
	//使用接口必须重写全部的方法
	@Override
	public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("test03提供服务了");
	}

	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		System.out.println("test03销毁了");
	}

	@Override
	public ServletConfig getServletConfig() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String getServletInfo() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public void init(ServletConfig config) throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("test03初始化了");
		
	}
}