JAVA SERVLET踩坑技术

今天给大家分享一下踩坑记录。

今天准备用Servlet重新开发一个web程序。

开始是通过实现Servlet今天实现的。

@WebServlet("/demo1")
public class ServletDemo1 implements Servlet {
    public void init(ServletConfig servletConfig) throws ServletException {
        System.out.println("init");
    }

    public ServletConfig getServletConfig() {
        return null;
    }

    public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
        System.out.println("service");
        servletResponse.getWriter().write("hello servlet");
    }

    public String getServletInfo() {
        return null;
    }

    public void destroy() {
        System.out.println("destroy");
    }
}

后台发现还有更好的实现方法通过继承HttpServlet.

@WebServlet("/demo3")
public class ServletDemo3 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Map<String, String[]> param = req.getParameterMap();
        for (String s : param.keySet()) {
            String[] strings = param.get(s);
            for (String string : strings) {
                System.out.println(s+":"+string);
            }
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Map<String, String[]> param = req.getParameterMap();
        for (String s : param.keySet()) {
            String[] strings = param.get(s);
            for (String string : strings) {
                System.out.println(s+":"+string);
            }
        }
        resp.setContentType("text/html;charset=utf-8");
        resp.getWriter().write("nihao");
    }
}

并能更好的区分 方法是GET 还是POST等。让代码符合RESF 的风格。

具体有那些方法接口如下