I have a server running rhel5 and jre 1.6. All my apps are running perfectly for now. But I want to install java 1.7 but keeping java 1.6 as the default so my running apps want be affected. If I want to install java 1.7 from a rpm how can I do this, and how can I run a my new app with the new version of java without changing default java version
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3 Answers
Install the java versions you want, running applications should not be affected despite the default java version being changed. Then run the alternatives utility to pick your default java version:
alternatives --config java alternatives --config javac Verify your setup with
java -version javac -version If you're unsure, try this on a non-production host first.
Edit: To force tomcat to use a specific java version, no matter what the default, place a setenv.sh in tomcat's bin directory containing
JAVA_HOME=/path/to/jdk Source: https://stackoverflow.com/questions/1698913/how-to-set-java-home-in-tomcat-config
- In addition to alternatives --config java, for jdk you must run alternatives --config javac to choose which jdk environment you want to run your application in.Zeeshan– Zeeshan2014-07-30 00:14:55 +00:00Commented Jul 30, 2014 at 0:14
- Problem is, even though my running apps use older java version I want to run only tomcat from a newer java version. How can I achieve this?ivcode– ivcode2014-08-11 06:32:16 +00:00Commented Aug 11, 2014 at 6:32
- 1@ivcode I've updated my answer.fuero– fuero2014-08-11 08:46:16 +00:00Commented Aug 11, 2014 at 8:46
First of all install Java 7/8 using:
sudo apt-get install openjdk-7-jdk Then you need to update alternatives using:
sudo update-alternatives --config java You will see:
There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ * 0 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 auto mode 1 /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java 1061 manual mode 2 /usr/lib/jvm/java-7-oracle/jre/bin/java 1062 manual mode Press enter to keep the current choice[*], or type selection number: Chose one that you need and type:
java -version Then you can run your app on Java 7 and after that rollback it to 6 version.
first you need to make sure that your java apps are running thier java/javac from an absolute path. now the default java is the java you have when you execute:
# java -version every java app you want to run must specify the absolute path according to your needs. to change the default execute:
# which java and find out where is your default java bin is located and change the link to your designated jdk
