一个小错误

Statement   stmt_Check=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
String   sql   =   "select   *   from   tAdmin   where   fPassword= ' "+   UserPwd   +   " '   and   fUserName= ' "   +   UserName   + " '   ";
ResultSet   RsLoginCheck   =   stmt_Check.executeQuery(sql);

if(RsLoginCheck.next())
{
String   a   =RsLoginCheck.getString( "fPurview ");
String   b= "超级用户 ";
if   (a==b)
{
out.print( "成功 ");
}
else
{
out.print( "失败 ");
}
 
}

经查询,a显示出来是 "超级用户 ",可是在IF语句结束以后,始终显示 "失败 ",不知为何?

------解决方案--------------------
if (a==b)
应该是
if (b.equals(a))