jsp+servlet实现最简单的增删改查代码分享实现最简单的增删改查代码分享
本文主要分享了jsp+servlet实现的最简单的增删改查代码。代码清晰明了，具有很好的参考价值，需要的朋友一
起来看下吧
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) {
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