首页编写一个Servlet，使程序能读取该Servlet的配置信息（使用ServletConfig），从中获得参数名为username,password,role对应的参数值，并输出到页面上。建议使用:<init-param>

编写一个Servlet，使程序能读取该Servlet的配置信息（使用ServletConfig），从中获得参数名为username,password,role对应的参数值，并输出到页面上。建议使用:<init-param>

时间: 2024-06-10 13:10:16 浏览: 97

在web.xml文件中设置Servlet的初始化参数。以下是示例代码： ``` @WebServlet("/configServlet") public class ConfigServlet extends HttpServlet { private String username; private String password; private String role; @Override public void init(ServletConfig config) throws ServletException { super.init(config); username = config.getInitParameter("username"); password = config.getInitParameter("password"); role = config.getInitParameter("role"); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); out.println("<html>"); out.println("<head><title>Servlet Config Parameter</title></head>"); out.println("<body>"); out.println("<h1>Servlet Config Parameter</h1>"); out.println("<p>Username: " + username + "</p>"); out.println("<p>Password: " + password + "</p>"); out.println("<p>Role: " + role + "</p>"); out.println("</body></html>"); out.close(); } } ``` 在web.xml文件中设置初始化参数： ``` <servlet> <servlet-name>configServlet</servlet-name> <servlet-class>com.example.ConfigServlet</servlet-class> <init-param> <param-name>username</param-name> <param-value>admin</param-value> </init-param> <init-param> <param-name>password</param-name> <param-value>123456</param-value> </init-param> <init-param> <param-name>role</param-name> <param-value>admin</param-value> </init-param> </servlet> ``` 访问该Servlet，将输出以下内容： ``` Servlet Config Parameter Username: admin Password: 123456 Role: admin ```

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