Springmvc+jdbc简单学生管理系统

package com.ffk.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import com.ffk.entity.Student; public class StudentDaoImpl implements StudentDao { public boolean stuIsExist = false; @Override public List<Student> findAll() { Connection conn = null; try{ List<Student> list = new ArrayList<>(); conn = DBUtil.getConnection(); String sql = "select s_no , s_name,s_age,s_address,s_class from t_student1015"; PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); while (rs.next()) { Student student = new Student(); int s_no = rs.getInt("s_no"); String s_name=rs.getString("s_name"); int s_age = rs.getInt("s_age"); String s_address = rs.getString("s_address"); String s_class = rs.getString("s_class"); student.setS_no(s_no); student.setS_name(s_name); student.setS_age(s_age); student.setS_address(s_address); student.setS_class(s_class); list.add(student); } rs.close(); ps.close(); return list; }catch (Exception e){ e.printStackTrace(); DBUtil.rollback(conn); return null; }finally { if (conn!= null) { DBUtil.close(conn); } } } @Override public void addStu(Student student) { Connection conn = null; try { conn = DBUtil.getConnection(); String sql = "insert into t_student1015 (s_no,s_name,s_age,s_address,s_class) values(?,?,?,?,?)"; PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1, student.getS_no()); ps.setString(2, student.getS_name()); ps.setInt(3, student.getS_age()); ps.setString(4, student.getS_address()); ps.setString(5, student.getS_class()); int n = ps.executeUpdate(); if (n >= 1) { System.out.println("添加成功"); }else { System.out.println("添加失败，用户名与存在"); stuIsExist = true; } ps.close(); } catch (Exception e){ e.printStackTrace(); DBUtil.rollback(conn); }finally { if (conn!= null) { DBUtil.close(conn); } } } @Override public void delStu(int s_no) { Connection conn = null; try { conn = DBUtil.getConnection(); String sql = "delete from t_student1015 where s_no=?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1, s_no); int n = ps.executeUpdate(); if (n >= 1) { System.out.println("删除成功"); }else { System.out.println("删除失败"); } }catch (Exception e){ e.printStackTrace(); DBUtil.rollback(conn); }finally { if (conn!= null) { DBUtil.close(conn); } } } @Override public void updateStu(Student stu) { Connection conn = null; try { conn = DBUtil.getConnection(); String sql = "update t_student1015 set s_name=?,s_age=?,s_address=?,s_class=? where s_no=?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, stu.getS_name()); ps.setInt(2, stu.getS_age()); ps.setString(3, stu.getS_address()); ps.setString(4, stu.getS_class()); ps.setInt(5,stu.getS_no()); int n = ps.executeUpdate(); if (n >= 1) { System.out.println("修改成功"); }else { System.out.println("修改失败"); } } catch (Exception e){ e.printStackTrace(); DBUtil.rollback(conn); }finally { if (conn!= null) { DBUtil.close(conn); } } } @Override public Student findById(int s_no) { Connection conn = null; try { Student stu = new Student(); conn = DBUtil.getConnection(); String sql = "select s_name,s_age,s_address,s_class from t_student1015 where s_no=?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1, s_no); ResultSet rs = ps.executeQuery(); while(rs.next()){ stu.setS_no(s_no); stu.setS_name(rs.getString("s_name")); stu.setS_age(rs.getInt("s_age")); stu.setS_address(rs.getString("s_address")); stu.setS_class(rs.getString("s_class")); } return stu; } catch (Exception e){ e.printStackTrace(); DBUtil.rollback(conn); return null; }finally { if (conn!= null) { DBUtil.close(conn); } } } }