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话不多说，请看代码
package ceet.ac.cn.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import ceet.ac.cn.model.Admin;
public class AdminDao {
public List<Admin> getAllAdmin(){ //查询所有信息
List<Admin> list = new ArrayList<Admin>(); //创建集合
Connection conn = DbHelper.getConnection();
String sql = "select * from admin"; //SQL查询语句
try {
PreparedStatement pst = conn.prepareStatement(sql);
ResultSet rst = pst.executeQuery();
while (rst.next()) {
Admin admin = new Admin();
admin.setId(rst.getInt("id")); //得到ID
admin.setUsername(rst.getString("username"));
admin.setUserpwd(rst.getString("userpwd"));
list.add(admin);
}
rst.close(); //关闭
pst.close(); //关闭
} catch (SQLException e) {
e.printStackTrace(); //抛出异常
}
return list; //返回一个集合
}
public boolean addAdmin(Admin admin){ //添加信息
String sql = "INSERT INTO `admin`(`id`,`username`,`userpwd`) VALUES (?,?,?)"; //添加的SQL语句
Connection conn = DbHelper.getConnection();
try {
PreparedStatement pst = conn.prepareStatement(sql);
pst.setInt(1, admin.getId());
pst.setString(2, admin.getUsername());
pst.setString(3, admin.getUserpwd());
int count = pst.executeUpdate();
pst.close();
return count>0?true:false; //是否添加的判断
} catch (SQLException e) {
e.printStackTrace();
}
return false;
}
public boolean updateAdmin(Admin admin){ //修改
String sql = "UPDATE `admin` SET `username`=?,`userpwd`=? WHERE `id` = ?"; //修改的SQL语句，根据ID修改
Connection conn = DbHelper.getConnection();
try {
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, admin.getUsername());
pst.setString(2, admin.getUserpwd());
pst.setInt(3, admin.getId()); //根据的ID
int count = pst.executeUpdate();
pst.close(); //关闭
return count>0?true:false; //是否修改的判断
} catch (SQLException e) {
e.printStackTrace();
}
return false;
}
public boolean deleteAdmin(int id){ //删除
String sql = "delete from admin where id = ?"; //删除的SQL语句，根据ID删除
Connection conn = DbHelper.getConnection();
try {
PreparedStatement pst = conn.prepareStatement(sql);
pst.setInt(1, id);
int count = pst.executeUpdate();
pst.close();
return count>0?true:false; //是否删除的判断
} catch (SQLException e) {
e.printStackTrace();
}
return false;
}
public Admin selectAdminById(int id){ //根据ID进行查询
Connection conn = DbHelper.getConnection();
String sql = "select * from admin where id = "+id;
Admin admin = null;
try {
PreparedStatement pst = conn.prepareStatement(sql);
ResultSet rst = pst.executeQuery();
while (rst.next()) {
admin = new Admin();
admin.setId(rst.getInt("id"));
admin.setUsername(rst.getString("username"));
admin.setUserpwd(rst.getString("userpwd"));
}
rst.close();
pst.close();
} catch (SQLException e) {
e.printStackTrace();
}
return admin; //返回
}
}
</div>
package ceet.ac.cn.dao;
import java.sql.Connection;
import java.sql.DriverManager;
/**
* 连接数据库
* @author 画船听雨眠
*
*/
public class DbHelper {
private static String url = "jdbc:mysql://localhost:3306/admin"; //数据库地址
private static String userName = "root"; //数据库用户名
private static String passWord = "359129127"; //数据库密码
private static Connection conn = null;
private DbHelper(){
}
public static Connection getConnection(){
if(null == conn){
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url, userName, passWord);
} catch (Exception e) {
e.printStackTrace();
}
}
return conn;
}
public static void main(String[] args) { //测试数据库是否连通
System.err.println(getConnection());
}
}
</div>
package ceet.ac.cn.model;
import java.io.Serializable;
public class Admin implements Serializable{ //数据封装类
private static final long serialVersionUID = 1L;
private int id;
private String username;
private String userpwd;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUserpwd() {
return userpwd;
}
public void setUserpwd(String userpwd) {
this.userpwd = userpwd;
}
}
</div>
package ceet.ac.cn.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import ceet.ac.cn.dao.AdminDao;
import ceet.ac.cn.model.Admin;
public class AddServlet extends HttpServlet{ //添加数据
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String username = req.getParameter("username");
String userpwd = req.getParameter("userpwd");
Admin admin = new Admin();
admin.setUsername(new String(username.getBytes("ISO-8859-1"),"UTF-8")); //转值，中文需要转换为utf-8
admin.setUserpwd(new String(userpwd.getBytes("ISO-8859-1"),"UTF-8"));
AdminDao dao = new AdminDao();
dao.addAdmin(admin);
req.getRequestDispatcher("ShowServlet").forward(req, resp);
}
}
</div>
package ceet.ac.cn.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import ceet.ac.cn.dao.AdminDao;
public class DeleteServlet extends HttpServlet{ //删除数据
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String idStr = req.getParameter("id"); //删除数据的ID，根据ID删除
if(idStr != null && !idStr.equals("")){
int id = Integer.valueOf(idStr);
AdminDao dao = new AdminDao();
dao.deleteAdmin(id);
}
req.getRequestDispatcher("ShowServlet").forward(req, resp);
}
}
</div>
package ceet.ac.cn.servlet;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import ceet.ac.cn.dao.AdminDao;
import ceet.ac.cn.model.Admin;
public class ShowServlet extends HttpServlet{ //显示全部数据
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
AdminDao dao = new AdminDao();
List<Admin> list = dao.getAllAdmin();
req.setAttribute("list", list);
req.getRequestDispatcher("index.jsp").forward(req, resp);
}
}
</div>
package ceet.ac