ASKNOW
export JAVA_HOME=/usr/local/java6 # or /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home on macOS export PATH=$JAVA_HOME/bin:$PATH java -version Use jenv or /usr/libexec/java_home -v 1.6 :
"C:\Program Files\Java\jdk1.6.0_45\bin\java" -jar yourLegacyApp.jar java 1.6.0 download
java -version