JavaWeb——request獲取相關路徑

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//        http://localhost:8080/DemoName/AServlet?username=xxx&password=yyy
        request.getScheme();//獲取協議，http
        request.getServerName();//獲取服務器名，localhost
        request.getServerPort();//獲取服務器端口，8080
        request.getContextPath();//獲取項目名，/DemoName
        request.getServletPath();//獲取Servlet路徑，/AServlet
        request.getQueryString();//獲取參數部分，即問號後面的部分，username=xxx&password=yyy
        request.getRequestURI();//獲取請求URI，即項目名+Servlet路徑，/DemoName/AServlet
        request.getRequestURL();//獲取請求URL，等於不包括參數的整個路徑，http://localhost:8080/DemoName/AServlet
    }