问题
After installing Intellij Idea 14, with OracleJDK 1.8 u25 (64 bit) on my 14.04 Ubuntu system, I cannot configure the Java SDK to use any JDK. When I navigate to Module Settings->SDK and click configure SDK, the add button, and then select /usr/java/jdk1.8.0_25 in the dialog, I get an error popup stating that "The selected directory is not a valid home for JDK."
I've checked the contents of the directory, which contains a bin folder with both java and javac inside, a lib folder and a jre folder.
I've tried selecting each of those in turn, to no avail, which I expected.
回答1:
I had the same problem, in my case I wasn't able to select any of the "openjdk" directories under /usr/lib/jvm/, I solved with:
sudo apt-get install openjdk-8-jdk
When restarting intellij it will find the path to the jdk automatically.
回答2:
For the ones who run into this problem although you select the right directory under /usr/lib/jvm, there is something you should know : The directories under /usr/lib/jvm are created when your system installs the minimum set of java tools. But it doesn't mean you have the development files available. You need to install the development files :
dnf install java-1.8.0-openjdk-devel
After installing this package, try to select the directory again and it should work.
回答3:
Evan Knowles posted a link to https://askubuntu.com/questions/130186/what-is-the-rationale-for-the-usr-directory. It provided me with the solution to the problem.
Instead of using the JDK at /usr/java/jdk1.8.0_25, I instead used the JDK at /usr/local/java/jdk1.8.0_25. The reasons that this works rather than the other are explained in detail within the link.
回答4:
I came across this error because I did not have JAVA_HOME set.
Adding export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64 (for openjdk 11 in my case) and export PATH=$JAVA_HOME/bin:$PATH to my ~/.bashrc and then running source ~/.bashrc solved the problem for me.
来源：https://stackoverflow.com/questions/30116439/selected-directory-is-not-a-valid-home-for-jdk-intellij-idea-on-ubuntu