add env_init script

shellscripts/env_init.sh

+#!/bin/bash
+# ======================================================================
+#
+# ENV INIT
+#
+# This is a helper tool for build processes with java and maven.
+# It sets a custom java and maven version
+#
+# ----------------------------------------------------------------------
+# 2024-02-18  first lines  <axel.hahn@unibe.ch>
+# ======================================================================
+
+cd "$( dirname "$0")" || exit 1
+
+typeset -A aJava
+typeset -A aMaven
+
+USAGE="
+This is a helper script to set the shell environment
+for a wanted version of java and maven.
+
+SYNTAX: source $0 [options]
+
+OPTIONS:
+    -j|--java <version>     Set Java version
+    -m|--maven <version>    Set Maven version
+    -h|--help               Show this help
+"
+
+
+if [ "$#" -eq 0 ]; then
+    echo "ERROR: parameter required. Use -h for help."
+    exit 2
+fi
+
+. "env_init.sh.cfg" || exit 3
+
+# ----------------------------------------------------------------------
+
+while [[ "$#" -gt 0 ]]; do case $1 in
+
+    -h|--help)
+        echo "$USAGE";
+        echo "Java versions:"
+        for v in "${!aJava[@]}"
+        do
+            echo "    $v ... ${aJava[$v]}"
+        done
+        echo
+        echo "Maven versions:"
+        for v in "${!aMaven[@]}"
+        do
+            echo "    $v ... ${aMaven[$v]}"
+        done
+        echo
+        exit 0
+        ;;
+
+    -j|--java)
+        if [ -z "${aJava[$2]}" ]; then
+            echo "ERROR: java version $2 is unknown on this system"
+            exit 4
+        fi
+        if [ ! -x "${aJava[$2]}/bin/java" ]; then
+            echo "ERROR: Path for java version $2 is wrong - ${aJava[$2]}/bin/java not executable"
+            exit 5
+        fi
+        echo ">>> Set JAVA version $2" 
+        export JAVA_HOME="${aJava[$2]}"
+        export PATH="${aJava[$2]}/bin:${PATH}"
+
+        echo "\$ java --version"
+        java --version
+        echo
+        shift; shift;
+        ;;
+
+    -m|--maven)
+        if [ -z "${aMaven[$2]}" ]; then
+            echo "ERROR: maven version $2 is unknown on this system"
+            exit 6
+        fi
+        if [ ! -x "${aMaven[$2]}/bin/mvn" ]; then
+            echo "ERROR: Path for mvn version $2 is wrong - ${aMaven[$2]}/bin/mvn not executable"
+            exit 7
+        fi
+        echo ">>> Set maven version $2" 
+        export PATH="${aMaven[$2]}/bin:${PATH}"
+
+        echo "\$ mvn --version"
+        mvn --version
+        echo
+        shift; shift;
+        ;;
+
+    *) if grep "^-" <<< "$1" >/dev/null ; then
+        echo; echo "ERROR: Unknown parameter: $1"; echo "Use -h for help."; exit 8
+       fi
+       break;
+       ;;
+
+esac; done
+
+if [ -n "$*" ]; then
+    echo "ERROR: No parameter supported. Use -h for help."
+    exit 9
+fi
+
+# ----------------------------------------------------------------------

shellscripts/env_init.sh.cfg.dist

+# -----------------------------------------------------------------------------
+# known java versions
+aJava[21]="/usr/lib/jvm/java-21-openjdk"
+aJava[23]="/usr/lib/jvm/java-23-openjdk"
+
+# -----------------------------------------------------------------------------
+# known maven versions
+aMaven["3.9.8"]="/opt/apache-maven-3.9.8"
+aMaven["3.9.9"]="/opt/apache-maven-3.9.9"
+
+# -----------------------------------------------------------------------------