使用servlet，jdbc將mysql中數據顯示在jsp頁面中,且實現直接刪除數據庫數據

 

package bean;

public class Student {
    private String sno;
    private String sname;
    private String sex;
    private int age;
    private String sdept;
    public String getSno() {
        return sno;
    }
    public void setSno(String sno) {
        this.sno = sno;
    }
    public String getSname() {
        return sname;
    }
    public void setSname(String sname) {
        this.sname = sname;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSdept() {
        return sdept;
    }
    public void setSdept(String sdept) {
        this.sdept = sdept;
    }

}

package bean; public class Student { private String sno; private String sname; private String sex; private int age; private String sdept; public String getSno() { return sno; } public void setSno(String sno) { this.sno = sno; } public String getSname() { return sname; } public void setSname(String sname) { this.sname = sname; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSdept() { return sdept; } public void setSdept(String sdept) { this.sdept = sdept; } }

 

 //包dao.DBConnection

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;

import bean.Student;

public class DBConnection {

    /**
     * 驅動類名稱
     */
    private static final String DRIVER_CLASS = "com.mysql.jdbc.Driver";

    /**
     * 數據庫連接字符串
     */
    private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/db3";

    /**
     * 數據庫用戶名
     */
    private static final String USER_NAME = "root";

    /**
     * 數據庫密碼
     */
    private static final String PASSWORD = "123456";

    /**
     * 數據庫連接類
     */
    private static Connection conn;

    /**
     * 數據庫操作類
     */
    private static Statement stmt;



    // 加載驅動
    static{
        try {
            Class.forName(DRIVER_CLASS);
        } catch (Exception e) {
            System.out.println("加載驅動錯誤");
            System.out.println(e.getMessage());
        }
    }

    // 取得連接
    private static Connection getConnection(){

        try {
            conn = DriverManager.getConnection(DATABASE_URL, USER_NAME, PASSWORD);
        } catch (Exception e) {
            System.out.println("取得連接錯誤");
            System.out.println(e.getMessage());
        }
        return conn;
    }


    public void ExecuteDel(String sql){

        try {
            stmt = getConnection().createStatement();
        } catch (Exception e) {
            System.out.println("statement取得錯誤");
            System.out.println(e.getMessage());
        }

        try {
            int rows = stmt.executeUpdate(sql);
            if(rows >= 1){
                System.out.println("成功刪除.....");
            } else {
                System.out.println("刪除失敗.....");
            }

        } catch (Exception e) {
            // TODO: handle exception
        }


    }

    public ArrayList<Student> getStudentList(String sql){

        ArrayList<Student> list = new ArrayList<Student>();

        // 取得數據庫操作對象
        try {
            stmt = getConnection().createStatement();
        } catch (Exception e) {
            System.out.println("statement取得錯誤");
            System.out.println(e.getMessage());
            return null;
        }

        try {

            // 查詢數據庫對象,返回記錄集(結果集)
            ResultSet rs = stmt.executeQuery(sql);

            // 循環記錄集，查看每一行每一列的記錄
            while (rs.next()) {
                // 第一列 sno
                String sno = rs.getString(1);

                // 第2列 sname
                String sname = rs.getString(2);

                // 性別
                String ssex = rs.getString(3);

                // 年齡
                int sage = rs.getInt(4);

                // 系
                String sdept = rs.getString(5);

                Student stu = new Student();
                stu.setSno(sno);
                stu.setSname(sname);
                stu.setAge(sage);
                stu.setSex(ssex);
                stu.setSdept(sdept);


                list.add(stu);
            }

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return list;
    }
}

package dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import java.util.ArrayList; import bean.Student; public class DBConnection { /** * 驅動類名稱 */ private static final String DRIVER_CLASS = "com.mysql.jdbc.Driver"; /** * 數據庫連接字符串 */ private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/db3"; /** * 數據庫用戶名 */ private static final String USER_NAME = "root"; /** * 數據庫密碼 */ private static final String PASSWORD = "123456"; /** * 數據庫連接類 */ private static Connection conn; /** * 數據庫操作類 */ private static Statement stmt; // 加載驅動 static{ try { Class.forName(DRIVER_CLASS); } catch (Exception e) { System.out.println("加載驅動錯誤"); System.out.println(e.getMessage()); } } // 取得連接 private static Connection getConnection(){ try { conn = DriverManager.getConnection(DATABASE_URL, USER_NAME, PASSWORD); } catch (Exception e) { System.out.println("取得連接錯誤"); System.out.println(e.getMessage()); } return conn; } public void ExecuteDel(String sql){ try { stmt = getConnection().createStatement(); } catch (Exception e) { System.out.println("statement取得錯誤"); System.out.println(e.getMessage()); } try { int rows = stmt.executeUpdate(sql); if(rows >= 1){ System.out.println("成功刪除....."); } else { System.out.println("刪除失敗....."); } } catch (Exception e) { // TODO: handle exception } } public ArrayList<Student> getStudentList(String sql){ ArrayList<Student> list = new ArrayList<Student>(); // 取得數據庫操作對象 try { stmt = getConnection().createStatement(); } catch (Exception e) { System.out.println("statement取得錯誤"); System.out.println(e.getMessage()); return null; } try { // 查詢數據庫對象,返回記錄集(結果集) ResultSet rs = stmt.executeQuery(sql); // 循環記錄集，查看每一行每一列的記錄 while (rs.next()) { // 第一列 sno String sno = rs.getString(1); // 第2列 sname String sname = rs.getString(2); // 性別 String ssex = rs.getString(3); // 年齡 int sage = rs.getInt(4); // 系 String sdept = rs.getString(5); Student stu = new Student(); stu.setSno(sno); stu.setSname(sname); stu.setAge(sage); stu.setSex(ssex); stu.setSdept(sdept); list.add(stu); } } catch (Exception e) { System.out.println(e.getMessage()); } return list; } }

 //包servlet.StuServlet

package servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import bean.Student;

import dao.DBConnection;

public class StuServlet extends HttpServlet {


    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        this.doPost(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        DBConnection db = new DBConnection();

        String sql = "select * from Student";

        ArrayList<Student> list = db.getStudentList(sql);

        request.setAttribute("list", list);
        request.getRequestDispatcher("index.jsp").forward(request, response);
    }



}

package servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.Student; import dao.DBConnection; public class StuServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { DBConnection db = new DBConnection(); String sql = "select * from Student"; ArrayList<Student> list = db.getStudentList(sql); request.setAttribute("list", list); request.getRequestDispatcher("index.jsp").forward(request, response); } }

 

 // DelServlet

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dao.DBConnection;

public class DelServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        this.doPost(request, response);
    }


    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String sno = request.getParameter("sno");

        //在mysql中語句：delete from student where Sno = '3';
        String sql = "delete from student where Sno = ' " + sno + " ' ";

        DBConnection db = new DBConnection();
        db.ExecuteDel(sql);

        request.getRequestDispatcher("stuservlet").forward(request, response);

    }


}

package servlet; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import dao.DBConnection; public class DelServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String sno = request.getParameter("sno"); //在mysql中語句：delete from student where Sno = '3'; String sql = "delete from student where Sno = ' " + sno + " ' "; DBConnection db = new DBConnection(); db.ExecuteDel(sql); request.getRequestDispatcher("stuservlet").forward(request, response); } }

 

 // web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

  <servlet>
    <servlet-name>StuServlet</servlet-name>
    <servlet-class>servlet.StuServlet</servlet-class>
  </servlet>
  <servlet>
    <servlet-name>DelServlet</servlet-name>
    <servlet-class>servlet.DelServlet</servlet-class>
  </servlet>


  <servlet-mapping>
    <servlet-name>StuServlet</servlet-name>
    <url-pattern>/stuservlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>DelServlet</servlet-name>
    <url-pattern>/delservlet</url-pattern>
  </servlet-mapping>


  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>StuServlet</servlet-name> <servlet-class>servlet.StuServlet</servlet-class> </servlet> <servlet> <servlet-name>DelServlet</servlet-name> <servlet-class>servlet.DelServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>StuServlet</servlet-name> <url-pattern>/stuservlet</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>DelServlet</servlet-name> <url-pattern>/delservlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>

 

 / / index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>list</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>

  <body>

    <table border="1">
        <tr>
            <td>編號</td>
            <td>姓名</td>
            <td>性別</td>
            <td>年齡</td>
            <td>所在系</td>
            <td>&nbsp;</td>
        </tr>

        <c:forEach items="${list}" var="stu">
            <tr>
                <td>${stu.sno }</td>
                <td>${stu.sname }</td>
                <td>${stu.sex }</td>
                <td>${stu.age }</td>
                <td>${stu.sdept }</td>
                <td><a href="delservlet?sno=${stu.sno }">刪除</a></td>
            </tr>
        </c:forEach>
    </table>


  </body>
</html>