Problem changing Java version using alternatives

Question

I'm not quite sure how I got into this mess, but for some reason I'm not able to change the current version of Java using alternatives. I can run alternatives --config java and type my selection but when I echo the version number for either java or javac, it spits back out 1.5 every time (despite alternatives showing the current version is 1.6). The server I'm working with is running RHEL5, by the way.

I have verified that the paths used in alternatives are pointing to the correct directories. Here's some output from my session:

[brilewis@myserver]$ sudo /usr/sbin/update-alternatives --config java

There are 3 programs which provide 'java'.

Selection Command

** 1 /usr/lib/jvm/jre-1.4.2-gcj/bin/java
+ 2 /usr/java/jdk1.5.0_10/bin/java
3 /usr/java/jdk1.6.0_16/bin/java

Enter to keep the current selection[+], or type selection number: 3

[brilewis@myserver]$ java -version

java version "1.5.0_10" Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_10-b03) Java HotSpot(TM) Server VM (build 1.5.0_10-b03, mixed mode)

[brilewis@myserver]$ sudo /usr/sbin/update-alternatives --config java

There are 3 programs which provide 'java'.

Selection Command

** 1 /usr/lib/jvm/jre-1.4.2-gcj/bin/java
2 /usr/java/jdk1.5.0_10/bin/java
+ 3 /usr/java/jdk1.6.0_16/bin/java

Enter to keep the current selection[+], or type selection number:

UPDATE: The following is the output of echo $PATH:

/usr/java/jdk1.5.0_10/bin:/usr/local/apache-ant-1.7.1/bin:/usr/local/apache-tomcat-6.0.24:/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/usr/NX/bin:/home/brilewis/bin

UPDATE (4/26/10): I followed Bert's suggestion and removed JAVA_HOME from the PATH environment var in /etc/profile. After doing this, I was able to use alternatives to change the version of Java. The only problem is that when I try to run javac, I get "-bash: javac: command not found". This does not happen when the version is set to 1.5.

Answer 1

For Oracle Java 6u30, once you've installed their RPMs you can configure alternatives:

/usr/sbin/alternatives --install "/usr/bin/java" "java" "/usr/java/default/bin/java" 2 \
--slave /usr/bin/javac javac /usr/java/default/bin/javac \
--slave /usr/bin/javadoc javadoc /usr/java/default/bin/javadoc \
--slave /usr/bin/jar jar /usr/java/default/bin/jar \
--slave /usr/bin/keytool keytool /usr/java/default/bin/keytool \
--slave /usr/bin/orbd orbd /usr/java/default/bin/orbd \
--slave /usr/bin/pack200 pack200 /usr/java/default/bin/pack200 \
--slave /usr/bin/rmid rmid /usr/java/default/bin/rmid \
--slave /usr/bin/rmiregistry rmiregistry /usr/java/default/bin/rmiregistry \
--slave /usr/bin/servertool servertool /usr/java/default/bin/servertool \
--slave /usr/bin/tnameserv tnameserv /usr/java/default/bin/tnameserv \
--slave /usr/bin/unpack200 unpack200 /usr/java/default/bin/unpack200 \
--slave /usr/share/man/man1/java.1.gz java.1.gz /usr/java/default/man/man1/java.1.gz \
--slave /usr/share/man/man1/keytool.1.gz keytool.1.gz /usr/java/default/man/man1/keytool.1.gz \
--slave /usr/share/man/man1/orbd.1.gz orbd.1.gz /usr/java/default/man/man1/orbd.1.gz \
--slave /usr/share/man/man1/pack200.1.gz pack200.1.gz /usr/java/default/man/man1/pack200.1.gz \
--slave /usr/share/man/man1/rmid.1.gz rmid.1.gz /usr/java/default/man/man1/rmid.1.gz \
--slave /usr/share/man/man1/rmiregistry.1.gz rmiregistry.1.gz /usr/java/default/man/man1/rmiregistry.1.gz \
--slave /usr/share/man/man1/servertool.1.gz servertool.1.gz /usr/java/default/man/man1/servertool.1.gz \
--slave /usr/share/man/man1/tnameserv.1.gz tnameserv.1.gz /usr/java/default/man/man1/tnameserv.1.gz \
--slave /usr/share/man/man1/unpack200.1.gz unpack200.1.gz /usr/java/default/man/man1/unpack200.1.gz

Then activate the configuration:

/usr/sbin/alternatives --config java

And select /usr/java/default/bin/java from the menu.

Plus you must gzip the man pages

gzip /usr/java/default/man/man1/*.1

Also, the Oracle java RPMs might have clobbered your alternatives symlink so force it to be normal.

ln -sf /etc/alternatives/java /usr/bin/java

Answer 2

I can change the default Java on CentOS using these steps:

1. Add the IBM JDK:

   alternatives --install /usr/bin/java java /opt/WebSphere/AppServer/java/bin/java 3
   

2. Set the new IBM JDK as default:

   alternatives --config java   (then select #3 in the list)
   

3. Type java -version at the prompt to see the result.