IntelliJ stores JDK version in Project Structure. Project Structure can be accessed via File -> Project Structure. JDK version can be changed via Project SDK section
Error occurs when class compiled with higher Java version than run with lower version. Major and minor version numbers stored in class bytecode at bytes 6 and 7
JAD is recommended for decompiling compiled Java applet classes. JD-GUI is currently the best decompiler for newer Java features. javap is included in JDK and can decompile bytecode
Remove extra hyphen '-' from VM arguments. Set _JAVA_OPTIONS system variable with -Xmx1024M value. Change JDK version from 1.8.0_05 to 1.8.0_172. Add JAVA_HOME environment variable pointing to JDK location
Command prompt shows JDK path when running 'java -version'. Control Panel > Programs > Java displays JDK path. System Properties > Advanced System Properties shows JAVA_HOME. PowerShell's Get-Command function can show Java installation location
Android Studio recommends using JBR JDK for optimal performance. Gradle builds use JAVA_HOME environment variable or PATH java command. JDK version must match or exceed Android Gradle Plugin requirements