吴裕雄--天生自然JAVA开发JSP-Servlet学习笔记:获得Web应用配置参数

<%-- 
    Document   : getWebParam
    Created on : 2020-4-11, 20:03:43
    Author     : Administrator
--%>

<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.Statement"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.sql.Connection"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>application测试</title>
    </head>
    <body>
        <%
//从配置参数中获取驱动
            String driver = application.getInitParameter("driver");
//从配置参数中获取数据库url
            String url = application.getInitParameter("url");
//从配置参数中获取用户名
            String user = application.getInitParameter("user");
//从配置参数中获取密码
            String pass = application.getInitParameter("pass");
//注册驱动
            Class.forName(driver);
//获取数据库连接
            Connection conn = DriverManager.getConnection(url, user, pass);
//创建Statement对象
            Statement stmt = conn.createStatement();
//执行查询
            ResultSet rs = stmt.executeQuery("select * from person");
        %>
        <table bgcolor="#9999dd" border="1" width="480">
            <%
                //遍历结果集
                while (rs.next()) {
            %>
            <tr>
                <td><%=rs.getString(1)%></td>
                <td><%=rs.getString(2)%></td>
                <td><%=rs.getString(3)%></td>
            </tr>
            <%
                }
            %>
        </table>
    </body>
</html>
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1"
         metadata-complete="true">
    <!-- 配置第一个参数:driver -->
    <context-param>
        <param-name>driver</param-name>
        <param-value>com.mysql.cj.jdbc.Driver</param-value>
    </context-param>
    <!-- 配置第二个参数:url -->
    <context-param>
        <param-name>url</param-name>
        <param-value>jdbc:mysql://localhost:3306/taobao</param-value>
    </context-param>
    <!-- 配置第三个参数:user -->
    <context-param>
        <param-name>user</param-name>
        <param-value>root</param-value>
    </context-param>
    <!-- 配置第四个参数:pass -->
    <context-param>
        <param-name>pass</param-name>
        <param-value>admin</param-value>
    </context-param>
  
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

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转载自www.cnblogs.com/tszr/p/12682051.html