javaweb ServletContext

<context-param>
        <param-name>url</param-name>
        <param-value>jdbc:mysql//localhost:3306/mybatis</param-value>
    </context-param>

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext context = this.getServletContext();
        String url = context.getInitParameter("url");
        resp.getWriter().print(url);
    }

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("进入ServletDemo04");
        ServletContext context = this.getServletContext();
        context.getRequestDispatcher("/url").forward(req,resp);//前边是转发的路径，后边是调用forward实现请求转发
    }

public class ServletDemo05 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext context = this.getServletContext();
        InputStream is = context.getResourceAsStream("/WEB-INF/classes/dh.properties");
        Properties properties = new Properties();
        properties.load(is);
        String username = properties.getProperty("username");
        String password = properties.getProperty("password");
        resp.getWriter().print(username+":"+password);
    }