servlet_15 数据库访问

来源：互联网发布：迈越网络刀塔传奇编辑：程序博客网时间：2024/05/29 16:55
本实例中我们需要把 mysql-connector-java-5.1.39-bin.jar 拷贝到 tomcat 下 lib 目录
Servlet 数据库访问实例：
package MyServlet;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;import java.sql.*;/** * Created by 1192126986 on 2017/1/19. */@WebServlet(name = "DataBaseAccess")public class DataBaseAccess extends HttpServlet {    //JDBC驱动名和数据库url    static final String JDBC_DRIVER="com.mysql.jdbc.Driver";    static final String DB_URL="jdbc:mysql://localhost:3306/runoob2";    //用户名和密码    static final String user="root";    static final String pass="123456";    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request,response);    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        Connection connection = null;        Statement statement = null;        // 设置响应内容类型        response.setContentType("text/html;charset=UTF-8");        PrintWriter out = response.getWriter();        String title = "Servlet Mysql 测试 - 菜鸟教程";        String docType = "<!DOCTYPE html>\n";        out.println(docType +                "<html>\n" +                "<head><title>" + title + "</title></head>\n" +                "<body bgcolor=\"#f0f0f0\">\n" +                "<h1 align=\"center\">" + title + "</h1>\n");        try {            //注册JDBC驱动器            Class.forName(JDBC_DRIVER);            //获取数据库链接对象            connection = DriverManager.getConnection(DB_URL, user, pass);            //创建数据库语句执行对象            statement = connection.createStatement();            //定义数据库SQL语句            String sql = "SELECT id,name,url FROM websites";            //执行sql语句，返回结果集            ResultSet res = statement.executeQuery(sql);            while (res.next()) {//遍历结果集                //获取结果集的id，name和url                int id = res.getInt("id");                String name = res.getString("name");                String url = res.getString("url");                out.println("ID:" + id);                out.println("站点名称：" + name);                out.println("站点url：" + url);                out.println("<br/>");            }            out.println("</body></html>");            //关闭            res.close();            statement.close();            connection.close();        } catch (SQLException se) {            // 处理 JDBC 错误            se.printStackTrace();        } catch (Exception e) {            // 处理 Class.forName 错误            e.printStackTrace();        }finally{            // 最后是用于关闭资源的块            try{                if(statement!=null)                    statement.close();            }catch(SQLException se2){            }            try{                if(connection!=null)                    connection.close();            }catch(SQLException se){                se.printStackTrace();            }        }    }}
1 0