不建议在jsp页面中直接写语句连接数据库

1.jsp
<%@ page contentType="text/html;charset=gb2312" language="java" import="java.sql.*" %>
<%ResultSet rs;
Connection conn;
Statement Stmt;
String sql="";

String userName="DB_USERNAME";
String userPwd="DB_PASSWORD";
String serverName="DB_SERVER";
String DBName="DATABASE_NAME";

String driverName = "org.gjt.mm.mysql.Driver";
Class.forName(driverName).newInstance();
String url = "jdbc:mysql://" + serverName + "/" + DBName;
conn = DriverManager.getConnection(url, userName, userPwd);
Stmt = conn.createStatement();
sql = "select * from userinfo";
rs = Stmt.executeQuery(sql);
%>

<%while(rs.next()){%>

<%=rs.getString("username")%>

<%}%>

这样也能连数据库，但是会让别人在源文件中看到自己的数据来源，不安全，不推荐使用。