When SecurityManager doesn't allow the "lookup" operation, it returns "localhost" instead of "127.0.0.1". Otherwise, getHostName method will look up the real hostname.
On 2/9/06, Geir Magnusson Jr <[EMAIL PROTECTED]> 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(); > >> } > >> } > > >
