Fixing the error: JAVA_HOME is not set on a Mac
While setting up Nutch on a Mac, I kept getting this error in the terminal:
Error: JAVA_HOME is not set
To fix the error on OS X 10.6.x (Snow Leopard), enter the following at the command prompt:
On 10.5 and above, the command line tool /usr/libexec/java_home dynamically finds the top Java version specified in Java Preferences for the current user. Using this method will allow the path to automatically change as software updates change Java versions.
So, if you try to run a command or script, and get the error (shown in red). . .
yourmac:~ username$ /Users/username/Sites/apache-nutch-1.1/bin/nutch inject crawl/crawldb /Users/username/Sites/apache-nutch-1.1/urls Error: JAVA_HOME is not set.
. . .set the Java_Home environment variable, and then try to run the command again. This time the response is the correct output for the command (shown in green.)
yourmac:~ username$ export JAVA_HOME=$(/usr/libexec/java_home) yourmac:~ username$ /Users/username/Sites/apache-nutch-1.1/bin/nutch inject crawl/crawldb /Users/username/Sites/apache-nutch-1.1/urls Injector: starting Injector: crawlDb: crawl/crawldb Injector: urlDir: /Users/username/Sites/apache-nutch-1.1/urls Injector: Converting injected urls to crawl db entries. Injector: Merging injected urls into crawl db. Injector: done yourmac:~ username$
It only lasts for one session. To set it permanently, you can add:
JAVA_HOME=/usr/libexec/java_home export JAVA_HOME;
to the file ~/.profile
To confirm you have java, enter this into the Terminal:
To determine the real path: