Javaweb学习12.17

今天练习了模糊查询

问题：在掉用dao层和servlet时候，容易丢三落四，忘记函数的修改，因为是复制的函数

public List<User_Bean> list(){//查询所有方法
String sql="select * from user";
Connection conn=DBUtil.getConnection();
Statement st=null;
List<User_Bean> list=new ArrayList<>();
ResultSet rs=null;
User_Bean bean=null;
try {
st=conn.createStatement();
rs=st.executeQuery(sql);
while(rs.next()) {
int id=rs.getInt("id");
String pass = rs.getString("pass");
String role = rs.getString("role");
if(role.equals("1")) {role="管理员";}
else if(role.equals("2")) {role="老师";}
else if(role.equals("3")) {role="学生";}
else {role="禁用";}
bean=new User_Bean(id,pass,role);
list.add(bean);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally {
DBUtil.close(rs, st, conn);
}
return list;
}