$java -version
java version "1.7.0"
IcedTea Runtime Environment (build 1.7.0-b21)
IcedTea Client VM (build 1.7.0-b21, mixed mode)
$which java
/usr/bin/java

error log:

[11/16/09 13:52:37] [SSH] Checking java version of java

Couldn't figure out the Java version of java

Exception in thread "main" java.lang.NoClassDefFoundError: null

Caused by: java.lang.ClassNotFoundException: null

at java.net.URLClassLoader$1.run(URLClassLoader.java:221)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:209)

at java.lang.ClassLoader.loadClass(ClassLoader.java:324)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)

at java.lang.ClassLoader.loadClass(ClassLoader.java:269)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:337)

Error: Could not find the main class.

Error: A JNI error has occurred, please check your installation and try again

[11/16/09 13:52:37] [SSH] Checking java version of /usr/bin/java

Couldn't figure out the Java version of /usr/bin/java

Exception in thread "main" java.lang.NoClassDefFoundError: null

Caused by: java.lang.ClassNotFoundException: null

at java.net.URLClassLoader$1.run(URLClassLoader.java:221)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:209)

at java.lang.ClassLoader.loadClass(ClassLoader.java:324)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)

at java.lang.ClassLoader.loadClass(ClassLoader.java:269)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:337)

Error: Could not find the main class.

Error: A JNI error has occurred, please check your installation and try again

[11/16/09 13:52:37] [SSH] Checking java version of /usr/java/default/bin/java

Couldn't figure out the Java version of /usr/java/default/bin/java

bash: /usr/java/default/bin/java: No such file or directory

[11/16/09 13:52:37] [SSH] Checking java version of /usr/java/latest/bin/java

Couldn't figure out the Java version of /usr/java/latest/bin/java

bash: /usr/java/latest/bin/java: No such file or directory

[11/16/09 13:52:38] [SSH] Checking java version of /usr/local/bin/java

Couldn't figure out the Java version of /usr/local/bin/java

bash: /usr/local/bin/java: No such file or directory

[11/16/09 13:52:38] [SSH] Checking java version of /usr/local/java/bin/java

Couldn't figure out the Java version of /usr/local/java/bin/java

bash: /usr/local/java/bin/java: No such file or directory

[11/16/09 13:52:38] [SSH] Checking java version of
/opt/hudson/builder2/jdk/bin/java

Couldn't figure out the Java version of /opt/hudson/builder2/jdk/bin/java

bash: /opt/hudson/builder2/jdk/bin/java: No such file or directory