使用servlet连接数据库

来源：互联网发布：数据录入查询系统编辑：程序博客网时间：2024/05/22 17:18

使用servlet连接数据库主要配置web.xml的<servlet>元素和<servlet-mapping>元素。

1、web.xml配置

<servlet>    <display-name>This is the description of my J2EE component</display-name>    <description>This is the description of my J2EE component</description>    <servlet-name>DBServlet</servlet-name>    <servlet-class>jijian.test.DBServlet</servlet-class>    <init-para>        <param-name>driverName</param-name>        <param-value>org.postgresql.Driver</param-value>        </init-para>    <init-para>        <param-name>username</param-name>        <param-value>itnms</param-value>    </init-para>    <init-para>        <param-name>password</param-name>        <param-value>itnms</param-value>    </init-para>    <init-param>        <param-name>dbName</param-name>        <param-value>itnms</param-value>    </init-param></servlet>

<servlet-mapping>    <servlet-name>DBServlet</servlet-name>    <url-pattern>/servlets/DBServlet</url-pattern></servlet-mapping>

2、servlet.java文件

package jijian.test;...public class DBServlet extends HttpServlet{            //定义一个继承HttpServlet的公有类    ServletConfig config=null;                        //定义一个ServletConfig对象    private String driverName="";                    //定义私有字符串常量并初始化    private String username="";                    //定义的数据库用户名    private String password="";                    //定义的数据库连接密码    private String dbName="";                        //定义的数据库名    private Connection conn;                        //初始化连接    private Statement stmt;                        //初始化数据库操作    ResultSet rs=null;                            //初始化结果集    public void init(ServletConfig config)throws ServletException{     super.init(config);                            //继承父类的init()方法     this.config=config;                            //获取配置信息     driverName=config.getInitParameter("driverName");//从配置文件中获取JDBC驱动名     username=config.getInitParameter("username");    //获取数据库用户名      password=config.getInitParameter("password");    //获取数据库连接密码      dbName=config.getInitParameter("dbName");    //获取要连接的数据库        }    public void doGet(HttpServletRequest req,HttpServletResponse resp)throws IOException,ServletException{    . . .    }        public void doPost(HttpServletRequest req,HttpServletResponse resp)throws IOException,ServletException{    . . .    }        public void destory(){    . . .    }}

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