学生信息管理系统），用到知识点：Servlet+jsp+MySQL.zip

package com.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.entity.Student; //操作数据库 //原子性的增，删，改，查（位于数据访问层） public class StudentDao { private static final String URL="jdbc:mysql://localhost:3306/studentDatabase"; private static final String USER="root"; private static final String PASSWORD="admin"; //要想增加，必须先判断是否已经存在 public static boolean isExist(int sno){ //如果等于null，说明不存在 return StudentDao.queryStudentBySno(sno)==null? false:true; } //增加方法 public static boolean addStudent(Student student) { Connection connection = null; PreparedStatement pstmt = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection(URL, USER, PASSWORD); String sql="insert into student values(?,?,?,?)"; pstmt = connection.prepareStatement(sql); pstmt.setInt(1, student.getSno()); pstmt.setString(2, student.getSname()); pstmt.setInt(3, student.getSage()); pstmt.setString(4, student.getSaddress()); int result = pstmt.executeUpdate(); if(result>0) { return true; } return false; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; }catch(Exception e) { e.printStackTrace(); return false; }finally { try { if(pstmt!=null)pstmt.close(); if(connection!=null)connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } //删除方法（根据sno进行） public static boolean deleteStudent(int sno) { Connection connection = null; PreparedStatement pstmt = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection(URL, USER, PASSWORD); String sql="delete from student where sno=?"; pstmt = connection.prepareStatement(sql); pstmt.setInt(1, sno); int result = pstmt.executeUpdate(); if(result>0) { return true; } return false; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; }catch(Exception e) { e.printStackTrace(); return false; }finally { try { if(pstmt!=null)pstmt.close(); if(connection!=null)connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } //修改方法（根据sno 修改student） public static boolean updateStudent(int sno,Student student) { Connection connection = null; PreparedStatement pstmt = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection(URL, USER, PASSWORD); String sql="update student set sname=?,sage=?,saddress=? where sno=?"; pstmt = connection.prepareStatement(sql); pstmt.setString(1, student.getSname()); pstmt.setInt(2, student.getSage()); pstmt.setString(3, student.getSaddress()); pstmt.setInt(4, student.getSno()); int result = pstmt.executeUpdate(); if(result>0) { return true; } return false; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return false; }catch(Exception e) { e.printStackTrace(); return false; }finally { try { if(pstmt!=null)pstmt.close(); if(connection!=null)connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } //查询方法 public static Student queryStudentBySno(int sno) { Student student=null; Connection connection = null; PreparedStatement pstmt = null; ResultSet rs = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection(URL, USER, PASSWORD); String sql="select * from student where sno=?"; pstmt = connection.prepareStatement(sql); pstmt.setInt(1, sno); rs = pstmt.executeQuery(); if(rs.next()) { int no = rs.getInt("sno"); String sname = rs.getString("sname"); int sage = rs.getInt("sage"); String saddress=rs.getString("saddress"); student=new Student(no,sname,sage,saddress); return student; } return null; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; }catch(Exception e) { e.printStackTrace(); return null; }finally { try { if(rs!=null)rs.close(); if(pstmt!=null)pstmt.close(); if(connection!=null)connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } //查询全部学生 public static List<Student> queryAllStudent(){ Student student=null; Connection connection = null; PreparedStatement pstmt = null; ResultSet rs = null; ArrayList<Student> students=new ArrayList<Student>(); try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection(URL, USER, PASSWORD); String sql="select * from student"; pstmt = connection.prepareStatement(sql); rs = pstmt.executeQuery(); while(rs.next()) { int sno = rs.getInt("sno"); String sname = rs.getString("sname"); int sage = rs.getInt("sage"); String saddress=rs.getString("saddress"); student=new Student(sno,sname,sage,saddress); students.add(student); } return students; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; }catch(Exception e) { e.printStackTrace(); return null; }finally { try { if(rs!=null)rs.close(); if(pstmt!=null)pstmt.close(); if(connection!=null)connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }