servlet-获取web.xml配置的init-param参数
1.web.xml配置的参数
1 <servlet> 2 <servlet-name>firstServlet</servlet-name> 3 <servlet-class>com.Conservlet</servlet-class> 4 <init-param> 5 <param-name>url</param-name> 6 <param-value>jdbc:mysql://localhost:3306/house</param-value> 7 </init-param> 8 <init-param> 9 <param-name>user</param-name> 10 <param-value>root</param-value> 11 </init-param> 12 <init-param> 13 <param-name>pwd</param-name> 14 <param-value>123456</param-value> 15 </init-param> 16 <init-param> 17 <param-name>driver</param-name> 18 <param-value>com.mysql.jdbc.Driver</param-value> 19 </init-param> 20 </servlet> 21 <servlet-mapping> 22 <servlet-name>firstServlet</servlet-name> 23 <url-pattern>/a</url-pattern> 24 </servlet-mapping>
2.servlet的doGet()获取值
1 protected void doGet(HttpServletRequest request, HttpServletResponse response) 2 throws ServletException, IOException { 3 // TODO Auto-generated method stub 4 try { 5 ServletConfig config = getServletConfig(); 6 String driver=config.getInitParameter("driver"); 7 String url=config.getInitParameter("url"); 8 String user=config.getInitParameter("user"); 9 String pwd=config.getInitParameter("pwd"); 10 response.setCharacterEncoding("gbk"); 11 //注册驱动 12 Class.forName(driver); 13 //建立连接 14 Connection conn = (Connection)DriverManager.getConnection(url, user, pwd); 15 Statement stm = (Statement)conn.createStatement(); 16 ResultSet rs = stm.executeQuery("select username,pwd from user"); 17 response.setContentType("text/html;charset=gbk"); 18 PrintStream out = new PrintStream(response.getOutputStream()); 19 out.println("<html>"); 20 out.println("<head>"); 21 out.println("<title>测试连接</title>"); 22 out.println("</head>"); 23 out.println("<body>"); 24 out.println("<table border=\"1\" width=\"300\""); 25 while(rs.next()) 26 { 27 out.println("<tr>"); 28 out.println("<td>"+rs.getString(1)+"</td>"); 29 out.println("<td>"+rs.getString(2)+"</td>"); 30 out.println("</tr>"); 31 } 32 out.println("</table>"); 33 out.println("</body>"); 34 out.println("</html>"); 35 } catch (Exception e) { 36 // TODO: handle exception 37 } 38 }
