Correct way to check Java version from BASH script

Question

How can I check whether Java is available (in the PATH or via JAVA_HOME) from a bash script and make sure the version is at least 1.5?

Answer 1

Perhaps something like:

if type -p java; then     echo found java executable in PATH     _java=java elif [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/java" ]];  then     echo found java executable in JAVA_HOME          _java="$JAVA_HOME/bin/java" else     echo "no java" fi  if [[ "$_java" ]]; then     version=$("$_java" -version 2>&1 | awk -F '"' '/version/ {print $2}')     echo version "$version"     if [[ "$version" > "1.5" ]]; then         echo version is more than 1.5     else                  echo version is less than 1.5     fi fi