public class UserBiz {
/**
* 用户登录
* @param uname 参数的定义,类型+变量名,被称为形参
* @param pwd
*/
public User login(String uname,String pwd) throws SQLException,ClassNotFoundException,NameNullException,Exception{
User user = null;
//短路算法
if( uname != null && pwd != null && !uname.equals("") && !pwd.equals("")){
UserDao dao = new UserDao();
try {
user = dao.login(uname, pwd);
}catch (SQLException e) {
//e.printStackTrace();
throw e;
}catch(ClassNotFoundException e){
//e.printStackTrace();
throw e;
}catch(Exception e){
//e.printStackTrace();
throw e;
}finally{
//关闭数据库的句柄
}
}else{
throw new NameNullException("用户名或密码为空,请重新输入");
}
return user;
}
}
if语句里 !uname.equals("") && !pwd.equals("")是干嘛用的,在下刚学java,谢谢大神们了,真的不懂啥意思