基于JSP+Servlet的租赁系统（毕业设计）源代码

package com.whut.lease.DAO; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import com.whut.lease.PO.Bogo; public class BogoPAO { private Statement state; private Connection conn; private ResultSet rs; /** * 新增留言 * @param l */ public void add(Bogo l){ try{ //得到连接 conn=DBtools.getConnection(); state= conn.createStatement(); String sql="INSERT INTO ofuserinfo VALUES( "+getMAX()+",'"+l.getSquare()+"','"+l.getPrice()+"',sysdate,'"+l.getBegintime()+"','"+l.getDeadline()+"')"; System.out.println(sql); state.executeUpdate(sql); }catch(SQLException e){ e.printStackTrace(); } finally{ DBtools.cloaeConn(conn); DBtools.cloaeState(state); } } /** * 得到列的最大值 * @return */ private int getMAX(){ Connection conn =null; Statement state =null; ResultSet rs =null; int max = 0; try{ conn = DBtools.getConnection(); state = conn.createStatement(); //执行SQL语句 String sql = "Select MAX(lid) max from ofuserinfo"; rs = state.executeQuery(sql); //取值 if(rs.next()){ max = rs.getInt("max"); } }catch(Exception e){ e.printStackTrace(); } finally{ DBtools.cloaeResultSet(rs); DBtools.cloaeState(state); DBtools.cloaeConn(conn); } return max+1; } /** * 根据sql语句查询数据库元素 * @return al */ public ArrayList getAllLogo(String sql) { ArrayList al = new ArrayList(); try{ conn = DBtools.getConnection(); state = conn.createStatement(); //执行sql语句 rs = state.executeQuery(sql); while(rs.next()){ Bogo p = new Bogo(); p.setLid(_id); p.setSquare(square); p.setLname(uname); p.setLsex(usex); p.setLbirth(ubirth); p.setLemail(uemail); p.setLtel(utel); p.setlID(uID); p.setLaddress(uaddress); al.add(p); } }catch(Exception e){ e.printStackTrace(); } finally{ DBtools.cloaeResultSet(rs); DBtools.cloaeState(state); DBtools.cloaeConn(conn); } return al; } /** * 通过ID查询 * @param sql * @return */ public Bogo findlogoById(int id){ Bogo p = new Bogo(); try{ conn = DBtools.getConnection(); state = conn.createStatement(); String sql="select * from ofuserinfo where lid="+id; rs = state.executeQuery(sql); if(rs.next()){ p.setLid(id); p.setSquare(square); p.setLname(uname); p.setLsex(usex); p.setLbirth(ubirth); p.setLemail(uemail); p.setLtel(utel); p.setlID(uID); p.setLaddress(uaddress); } }catch(Exception e){ e.printStackTrace(); } finally{ DBtools.cloaeResultSet(rs); DBtools.cloaeState(state); DBtools.cloaeConn(conn); } return p; } /** * 通过ＩＤ删除 * @param id */ public void deleteById(int id){ try{ //得到连接 conn=DBtools.getConnection(); state= conn.createStatement(); String sql="delete from ofuserinfo where lid="+id; state.executeUpdate(sql); }catch(SQLException e){ e.printStackTrace(); } finally{ DBtools.cloaeConn(conn); DBtools.cloaeState(state); } } /** * 修改数据库中的信息 * @param p */ public void updataById(Bogo p){ try{ //得到连接 conn=DBtools.getConnection(); state= conn.createStatement(); String sql="update ofuserinfo t set user_name='"+p.getLname()+"', where t.lid="+p.getLid(); state.executeUpdate(sql); }catch(SQLException e){ e.printStackTrace(); } finally{ DBtools.cloaeConn(conn); DBtools.cloaeState(state); } } /** * 获得总条数 * @return */ public int totalRoles(){ //设置数据库变量 Connection conn =null; Statement state = null; ResultSet rs = null; int num = 0; try{ conn = DBtools.getConnection(); state = conn.createStatement(); String sql ="select count(lid) nu from ofuserinfo"; rs = state.executeQuery(sql); if(rs.next()){ num = rs.getInt("nu"); } }catch(Exception e){ e.printStackTrace(); } finally{ DBtools.cloaeResultSet(rs); DBtools.cloaeState(state); DBtools.cloaeConn(conn); } return num; } }