基于javaweb+jsp+serverlet

package help; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import bean.*; import database.DatabaseConn; public class helpControlBooks { private DatabaseConn conn = new DatabaseConn(); /** * 查询所有图书 * * */ public Books getAllBooks(String id){ Books books = null; books = new Books(); String sql = "SELECT * FROM books WHERE id = '" + id + "'"; ResultSet rs = conn.executeQuery(sql); try { if (rs != null && rs.next()) { books.setId(rs.getInt(1)); books.setType(rs.getString(2)); books.setName(rs.getString(3)); books.setAuthor(rs.getString(4)); books.setPress(rs.getString(5)); books.setPrice(rs.getInt(6)); books.setTime(rs.getString(7)); books.setNumber(rs.getInt(8)); books.setRemark(rs.getString(9)); books.setState(rs.getInt(10)); books.setJs(rs.getString(11)); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } conn.close(); return books; } /** * 查询所有图书id * @return */ public ArrayList<String> getBooksId(){ ArrayList<String> a=new ArrayList<String>(); String sql = "SELECT id FROM books"; ResultSet rs = conn.executeQuery(sql); try { while (rs != null && rs.next()) a.add(rs.getString(1)); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } conn.close(); return a; } /** * 删除图书 * @param id */ public void deleteBook(String id){ String sql = "DELETE FROM books WHERE id = '" + id + "'"; conn.executeUpdate(sql); conn.close(); } /** * 修改图书在馆状态 * @param id * @param s * @return */ public boolean updateState(int id,int state){ String sql="UPDATE books SET state = '" + state + "' WHERE id = '" + id + "'"; conn.executeUpdate(sql); conn.close(); return true; } /**获取图书的数量**/ public int getBookNumber(String id){ int nu = 0; String sql = "SELECT number FROM books WHERE id = '" + id + "'"; ResultSet rs = conn.executeQuery(sql); try { nu=rs.getInt(0); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } conn.close(); return nu; } /** * 借书时修改图书数量 * * * */ public boolean updateNumber(int id,int number){ String sql="UPDATE books SET number = '" + number + "' WHERE id = '" + id + "'"; conn.executeUpdate(sql); conn.close(); return true; } /** * 还书时修改图书数量 * * * */ public boolean updateNumberIn(int id,int number){ String sql="UPDATE books SET number = '" + number + "' WHERE id = '" + id + "'"; conn.executeUpdate(sql); conn.close(); return true; } /** *借书后记录到数据库 * @param ab * @return */ public int insertDate(Borrow ab){ int i = 0; String sql = "INSERT INTO borrow(username,id,time) VALUES('"+ ab.getUsername() +"' ,'" + ab.getId()+"','" + ab.getTime() + "')"; i = conn.executeUpdate(sql); conn.close(); return i; } /** * 还书后操作 */ public void deleteDate(Borrow borrow){ String sql = "DELETE FROM borrow WHERE id = '" + borrow.getId() + "' and username = '" + borrow.getUsername() + "'"; conn.executeUpdate(sql); conn.close(); } /**查询借出的图书**/ public ArrayList<String> getBooksBorrow(){ ArrayList<String> B = new ArrayList<String>(); String sql="SELECT id FROM borrow"; ResultSet rs=conn.executeQuery(sql); try { while(rs.next()){ B.add(String.valueOf(rs.getInt(1))); } } catch (SQLException e) { // TODO: handle exception e.printStackTrace(); } conn.close(); return B; } /** * 查询借书信息 * * */ public Borrow getBorrowDate(String id){ Borrow borrow = null; borrow = new Borrow(); String sql = "SELECT * FROM borrow where id="+id+""; ResultSet rs = conn.executeQuery(sql); try { if (rs != null && rs.next()) { borrow.setUsername(rs.getString(1)); borrow.setId(rs.getInt(2)); borrow.setTime(rs.getString(3)); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } conn.close(); return borrow; } }