很简单的图书管理系统，主要业务是借书和还书（Java + Servlet + JSP + CSS）.zip

package Dao.Impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import Values.TB_Borrow; import DBUtil.DBUtil; import Dao.BorrowDao; public class BorrowDaoImpl implements BorrowDao{ @Override public List<TB_Borrow> queryBorrowById(String id) { Connection conn = DBUtil.open(); PreparedStatement pstmt = null; String sql = "select * from tb_borrow where reader_id=?;"; List<TB_Borrow> list = new ArrayList<TB_Borrow>(); try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, id); ResultSet rs = pstmt.executeQuery(); while(rs.next()){ TB_Borrow tb = new TB_Borrow(); tb.setRe_id(rs.getString(1)); tb.setBr_id(rs.getString(2)); tb.setBr_name(rs.getString(3)); tb.setBr_author(rs.getString(4)); tb.setBr_img(rs.getString(5)); tb.setBr_num(rs.getInt(6)); list.add(tb); } return list; } catch (SQLException e) { e.printStackTrace(); }finally{ DBUtil.close(conn, pstmt); } return null; } @Override public Boolean insertBorrow(TB_Borrow tb) { Boolean result = false; Connection conn = DBUtil.open(); PreparedStatement pstmt = null; String sql = "insert into TB_Borrow values(?,?,?,?,?,?);"; try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, tb.getRe_id()); pstmt.setString(2,tb.getBr_id()); pstmt.setString(3,tb.getBr_name()); pstmt.setString(4, tb.getBr_author()); pstmt.setString(5,tb.getBr_img()); pstmt.setInt(6, tb.getBr_num()); pstmt.executeUpdate(); result = true; return result; } catch (SQLException e) { e.printStackTrace(); } return result; } @Override public Boolean updateBorrow(String re_id,String id,int num) { Boolean result = false; Connection conn = DBUtil.open(); PreparedStatement pstmt = null; String sql = "update tb_borrow set book_num=? where reader_id=? and book_id=?;"; try { pstmt = conn.prepareStatement(sql); pstmt.setInt(1, num); pstmt.setString(2, re_id); pstmt.setString(3,id); pstmt.executeUpdate(); result = true; return result; } catch (SQLException e) { e.printStackTrace(); } return result; } @Override public Boolean deleteBorrow() { Boolean result = false; Connection conn = DBUtil.open(); Statement stmt = null; String sql = "delete from tb_borrow where book_num=1;"; try { stmt = conn.createStatement(); stmt.executeUpdate(sql); result = true; return result; } catch (SQLException e) { e.printStackTrace(); } return result; } @Override public TB_Borrow queryBorrowByIdId(String re_id, String id) { Connection conn = DBUtil.open(); PreparedStatement pstmt = null; String sql = "select * from tb_borrow where reader_id=? and book_id=?;"; TB_Borrow tb = new TB_Borrow(); try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, re_id); pstmt.setString(2, id); ResultSet rs = pstmt.executeQuery(); if(rs.next()){ tb.setRe_id(rs.getString(1)); tb.setBr_id(rs.getString(2)); tb.setBr_name(rs.getString(3)); tb.setBr_author(rs.getString(4)); tb.setBr_img(rs.getString(5)); tb.setBr_num(rs.getInt(6)); return tb; } } catch (SQLException e) { e.printStackTrace(); }finally{ DBUtil.close(conn, pstmt); } return null; } @Override public List<TB_Borrow> queryBorrow() { Connection conn = DBUtil.open(); Statement stmt = null; List<TB_Borrow> list = new ArrayList<TB_Borrow>(); String sql = "SELECT * from tb_Borrow;"; try { stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery(sql); while(rs.next()){ TB_Borrow tb = new TB_Borrow(); tb.setRe_id(rs.getString(1)); tb.setBr_id(rs.getString(2)); tb.setBr_name(rs.getString(3)); tb.setBr_author(rs.getString(4)); tb.setBr_img(rs.getString(5)); tb.setBr_num(rs.getInt(6)); list.add(tb); } return list; } catch (SQLException e) { e.printStackTrace(); }finally{ DBUtil.close(conn, stmt); } return null; } }