CODEWITHSUNDEEP
java
m_pGladiator
m_pGladiator

Reputation: 8620

Is there an uniform way to detect the installed java on linux?

Is there a way to detect the installed java on various different Linux distributions? With Windows you could use the JAVA_HOME or the registry for that, but Linux? Can it be also detected if this is JDK, JRE, 32 or 64 bit?

REPHRASE: If I need 64-bit JDK on Linux, how do I programatically check that it is present and inform the user that he has some other java instead?

Upvotes: 4

Views: 6299

Answers (5)

Thor
Thor

Reputation: 6656

There are many answers here helping you to check if Java is installed. If this is the case you can get more information programatically. SystemUtils of commons-lang gives you many information about the Java version actually running.

Upvotes: 0

Miggs
Miggs

Reputation: 11

You can use java -version in the terminal to find out some info.

Upvotes: 1

andronikus
andronikus

Reputation: 4210

To see the file called by the java command use which java, although this will often be just a symlink to the real executable, such as /usr/bin/java. This works across all distros as far as I know.

On some Linux distros you can use update-alternatives --display java (possibly with sudo) to see a list of all the java executables installed on your system, and it will also tell you which one the symlink points to. You can switch between them by using the --config option instead.

Upvotes: 1

AlexR
AlexR

Reputation: 115328

No unified way. You can use JAVA_HOME env. variable but it is not defined on all machines. But there is a "common" way like ls /usr/java/*/bin/java | tail -1.

This should give in most cases you the latest version.

Upvotes: 1

Mahmoud Hanafy
Mahmoud Hanafy

Reputation: 8228

You can always use java -version.

This works on all platforms, but make sure that Java is included in the system PATH variable.

Upvotes: 5

Related Questions