Ok.
<aside>
The behavior strikes me as dumb. Why return a textual representation?
What good does that do anyone? The caller has no clue there was a
problem...
</aside>
geir
Paulex Yang wrote:
As I commented in the JIRA, further study shows some interesting facts,
first, my prior patch is redundant, the actual bug is
http://issues.apache.org/jira/browse/HARMONY-84.
second, there is another different behavior of getHostName() between RI
and Harmony, but I consider it as RI's bug:
The java spec of getHostName() says:
<spec>*
Returns: *the host name for this IP address, or if the operation is not
allowed by the security check, the textual representation of the IP
address.
</spec>
But the following test shows RI will return host name instead of IP
address if the host name can be got without reverse name lookup.
<code>
public class HostNameTest{
public static void main(String[] args) throws Exception{
InetAddress addr = InetAddress.getByName("localhost");
InetAddress addr2 = InetAddress.getByAddress(new byte[]{127, 0,
0, 1});
SecurityManager sm = new Inet_SecurityManager();
System.setSecurityManager(sm);
System.out.println(addr.getHostName());
System.out.println(addr2.getHostName());
}
static class Inet_SecurityManager extends SecurityManager {
public void checkConnect(String host, int port) {
super.checkConnect(host,port);
throw new SecurityException();
}
}
}
</code>
RI outputs:
localhost
127.0.0.1
Harmony outputs:
127.0.0.1
127.0.0.1
This time, Harmony win :-D .
Geir Magnusson Jr wrote:
isn't "localhost" actually something in the local hosts file? Don't
you want to look this up?
Paulex Yang (JIRA) wrote:
[ http://issues.apache.org/jira/browse/HARMONY-73?page=all ]
Paulex Yang updated HARMONY-73:
-------------------------------
Attachment: InetAddress.patch
A suggested modification is to add these two lines before Ln. 296 of
java.net.InetAddress,
if(this == LOOPBACK){
return "localhost";
}
So that the getHostName() will return "localhost" instead of
"127.0.0.1".
The patch is attached.
java.net.InetAddress.getLocalHost() returns wrong host name for
loopback address
---------------------------------------------------------------------------------
Key: HARMONY-73
URL: http://issues.apache.org/jira/browse/HARMONY-73
Project: Harmony
Type: Bug
Components: Classlib
Reporter: Svetlana Samoilenko
Priority: Minor
Attachments: InetAddress.patch
J2se 1.4.2 and 5.0 specifications for
java.net.InetAddress.getLocalHost() read, that if there is a
security manager, its checkConnect method is called with the local
host name and -1 as its arguments to see if the operation is
allowed. If the operation is not allowed, an InetAddress
representing the loopback address is returned as
hostname/hostaddress (as followed from toString() specification).
The test listed below shows that the returned loopback address has
wrong hostname, "127.0.0.1" instead of "loopback".
Inet_SecurityManager class is called twice and therefore host name
is substituted with hostaddress address.
Code to reproduce: import java.net.*; public class test2 {
public static void main(String[] args) { try {
System.setSecurityManager(new Inet_SecurityManager());
System.out.println("Loopback address = " +
InetAddress.getLocalHost());
} catch (Exception e){
System.out.println("Unexpected exception = " + e); }; }
} class Inet_SecurityManager extends SecurityManager { public
void checkConnect(String host, int port) {
super.checkConnect(host,port); throw new SecurityException();
}
}
Steps to Reproduce: 1. Build Harmony (check-out on 2006-01-30) j2se
subset as described in README.txt. 2. Compile test2.java using BEA
1.4 javac
javac -d . test2.java
3. Run java using compatible VM (J9)
java -showversion test2
Output: C:\tmp>C:\jrockit-j2sdk1.4.2_04\bin\java.exe -showversion
test2 java version "1.4.2_04" Java(TM) 2 Runtime Environment,
Standard Edition (build 1.4.2_04-b05) BEA WebLogic JRockit(TM)
1.4.2_04 JVM (build ari-31788-20040616-1132-win-ia32, Native
Threads, GC strategy: parallel) Inet_SecurityManager :host= nswssamoil1
Inet_SecurityManager :port= -1
Loopback address = localhost/127.0.0.1
C:\tmp>C:\harmony\trunk\deploy\jre\bin\java -showversion test2 (c)
Copyright 1991, 2005 The Apache Software Foundation or its
licensors, as applicable. Inet_SecurityManager :host= nswssamoil1
Inet_SecurityManager :port= -1
Inet_SecurityManager :host= localhost
Inet_SecurityManager :port= -1
Loopback address = 127.0.0.1/127.0.0.1
Suggested junit test case:
------------------------ InetAddressTest.java
------------------------------------------------- import java.net.*;
import junit.framework.*; public class InetAddressTest extends
TestCase { public static void main(String[] args) {
junit.textui.TestRunner.run(InetAddress.class); } public
void test_getLocalHost() { try{
System.setSecurityManager(new Inet_SecurityManager());
String hostname=InetAddress.getLocalHost().getHostName();
assertEquals("localhost", hostname);
} catch (Exception e){ fail("Unexpected
exception = " + e); }; } }
class Inet_SecurityManager extends SecurityManager { public void
checkConnect(String host, int port) {
super.checkConnect(host,port); throw new SecurityException();
}
}
