. Usher in javavmwrapper 2.0, a rewrite of the wrapper scripts designed to

  allow the simple use of multiple VMs.  Brief detail of the main changes:
  . When a VM is registered, symbolic links for its executables are
    created in ${LOCALBASE}/bin.  This allows people to just type
    'java', 'javac', etc. without having to add the VM installation
    directory to their PATH.
  . The actual 'java' that is executed via one of these symlinks is
    determined by the order of the (sorted) configuration file
    ${LOCALBASE}/etc/javavms and by the environment variables
    JAVA_VERSION, JAVA_OS and JAVA_VENDOR which function to select
    a VM as they do in the ports framework.
. There is a new command, checkvms, to sanity check the configuration
  and symlinks.
. The "javavm" executable is currently retained in its original capacity
  as a synonym for Java for backward compatibility.  However, its use
  is deprecated.
. Temporarily set MAINTAINER to myself to make monitoring any initial
  bug reports easier.  The intent is to convert it to java@ at a later
  date.

This is built on the ideas of znerd, hq and Shelton C. Johnson Jr., with
hq and Shelton contributing code and reviews.

PR:		27079, 39080
Reviewed by:	hq, Shelton C. Johnson Jr. <shelton_c_j@yahoo.com>

5 files changed, 512 insertions, 36 deletions

diff --git a/java/javavmwrapper/Makefile b/java/javavmwrapper/Makefile
index 780013538979..6f69805e8ca5 100644
--- a/java/javavmwrapper/Makefile
+++ b/java/javavmwrapper/Makefile
@@ -8,12 +8,12 @@
 #
 
 PORTNAME=	javavmwrapper
-PORTVERSION=	1.5
+PORTVERSION=	2.0
 CATEGORIES=	java
 MASTER_SITES=	# none
 DISTFILES=	# none
 
-MAINTAINER=	ports@FreeBSD.org
+MAINTAINER=	glewis@FreeBSD.org
 COMMENT=	Wrapper script for various Java Virtual Machines
 
 NO_BUILD=	yes
@@ -24,6 +24,7 @@ SCRIPTS=	classpath javavmwrapper
 # This is normally defined by bsd.java.mk when USE_JAVA is defined, but
 # we can't do that here since it would result in a circular dependency
 JAVALIBDIR=	${LOCALBASE}/share/java/classes
+PKGINSTALL=	${WRKDIR}/pkg-install
 
 do-fetch:
 	@${DO_NADA}
@@ -32,13 +33,19 @@ do-configure:
 .for _script in ${SCRIPTS}
 	${SED} -e 's|%%PREFIX%%|${PREFIX}|;' \
 	       -e 's|%%JAVALIBDIR%%|${JAVALIBDIR}|;' \
-		<${SRC}/${_script}.sh >${WRKDIR}/${_script}.sh
+		${SRC}/${_script}.sh >${WRKDIR}/${_script}.sh
 .endfor
+	${SED} -e 's|%%LOCALBASE%%|${LOCALBASE}|;' pkg-install > ${PKGINSTALL}
 
 do-install:
 	${INSTALL_SCRIPT} ${WRKDIR}/classpath.sh ${PREFIX}/bin/classpath
 	${INSTALL_SCRIPT} ${WRKDIR}/javavmwrapper.sh ${PREFIX}/bin/javavm
 	${LN} -sf ${PREFIX}/bin/javavm ${PREFIX}/bin/registervm
 	${LN} -sf ${PREFIX}/bin/javavm ${PREFIX}/bin/unregistervm
+	${LN} -sf ${PREFIX}/bin/javavm ${PREFIX}/bin/checkvms
+
+post-install:
+	${SETENV} PKG_PREFIX=${PREFIX} ${SH} ${PKGDIR}/pkg-install ${PKGNAME} \
+		POST-INSTALL
 
 .include <bsd.port.mk>
diff --git a/java/javavmwrapper/pkg-deinstall b/java/javavmwrapper/pkg-deinstall
new file mode 100644
index 000000000000..3075b66c5428
--- /dev/null
+++ b/java/javavmwrapper/pkg-deinstall
@@ -0,0 +1,45 @@
+#!/bin/sh
+#
+# $FreeBSD$
+
+export PATH=/bin:/sbin:/usr/bin:/usr/sbin
+
+# Run this script at the pre-deinstall stage
+if [ "x${2}" != "xDEINSTALL" ]; then
+    exit 0
+fi
+
+# The configuration file
+CONF="${PKG_PREFIX}/etc/javavms"
+
+# Ensure the configuration file exists
+if [ ! -f "${CONF}" ]; then
+    exit 0
+fi
+
+# Ensure the configuration file has the correct permissions
+if [ ! -r "${CONF}" ]; then
+    echo "error: can't read configuration file ${CONF}" 1>&2
+    exit 1
+fi
+
+# Destroy the symbolic links that were created for every executable for a VM.
+cat "${CONF}" | \
+(
+while read JAVAVM; do
+    VM=`echo "${JAVAVM}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+    JAVA_HOME=`dirname "${VM}"`
+    JAVA_HOME=`dirname "${JAVA_HOME}"`
+    for exe in "${JAVA_HOME}"/bin/* "${JAVA_HOME}"/jre/bin/*; do
+        exe=`basename "${exe}"`
+        if [ -L "${PKG_PREFIX}/bin/${exe}" -a \
+             "`ls -ld "${PKG_PREFIX}/bin/${exe}" 2>/dev/null | \
+               awk '/->/{print $NF;exit 0}END{exit 1}'`" = \
+             "${PKG_PREFIX}/bin/javavm" ]; then
+            rm "${PKG_PREFIX}/bin/${exe}"
+        fi
+    done;
+done;
+)
+
+exit 0
diff --git a/java/javavmwrapper/pkg-install b/java/javavmwrapper/pkg-install
new file mode 100644
index 000000000000..8f6d67f8195a
--- /dev/null
+++ b/java/javavmwrapper/pkg-install
@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+# $FreeBSD$
+
+LOCALBASE=%%LOCALBASE%%
+
+# This script runs during post-install
+if [ "x${2}" != "xPOST-INSTALL" ]; then
+    exit 0
+fi
+
+# Ensure all JDKs and JREs are installed
+for jvm in "${LOCALBASE}"/*jdk* "${LOCALBASE}"/*jre*; do
+    if [ -x "${jvm}/bin/java" ]; then
+        "${PKG_PREFIX}"/bin/registervm "${jvm}/bin/java"
+    fi
+done
+
+# Ensure all VMs are configured correctly
+"${PKG_PREFIX}"/bin/checkvms
diff --git a/java/javavmwrapper/pkg-plist b/java/javavmwrapper/pkg-plist
index dfb07441ae51..8ec477d3c9db 100644
--- a/java/javavmwrapper/pkg-plist
+++ b/java/javavmwrapper/pkg-plist
@@ -2,3 +2,4 @@ bin/classpath
 bin/javavm
 bin/registervm
 bin/unregistervm
+bin/checkvms
diff --git a/java/javavmwrapper/src/javavmwrapper.sh b/java/javavmwrapper/src/javavmwrapper.sh
index 17dfa4df57e2..b6447448911f 100644
--- a/java/javavmwrapper/src/javavmwrapper.sh
+++ b/java/javavmwrapper/src/javavmwrapper.sh
@@ -15,77 +15,340 @@
 # Maxim Sobolev
 # ----------------------------------------------------------------------------
 #
+# ----------------------------------------------------------------------------
+# "THE BEER-WARE LICENSE" (Revision 42, (c) Poul-Henning Kamp):
+# Greg Lewis <glewis@FreeBSD.org> substantially rewrote this file.  As long
+# as you retain this notice you can do whatever you want with this stuff. If
+# we meet some day, and you think this stuff is worth it, you can buy me a
+# beer in return.
+#
+# Greg Lewis
+# ----------------------------------------------------------------------------
+#
 # $FreeBSD$
 #
-# MAINTAINER= sobomax@FreeBSD.org
+# MAINTAINER=java@FreeBSD.org
+
+export PATH=/bin:/sbin:/usr/bin:/usr/sbin
 
 PREFIX="%%PREFIX%%"
 CONF="${PREFIX}/etc/javavms"
 IAM=`basename "${0}"`
+MAKE=/usr/bin/make
 
-tryrunVM () {
+#
+# Try to run a Java command.
+#
+tryJavaCommand () {
+    # Check for the command being executable and exec it if so.
     if [ -x "${1}" ]; then
         exec "${@}"
     fi
 
-    /bin/echo "${IAM}: warning: couldn't start specified JavaVM - \"${1}\"" >&2
+    echo "${IAM}: warning: couldn't run specified Java command - \"${1}\"" >&2
+}
+
+#
+# Create symbolic links for all of a Java VMs executables.
+#
+createJavaLinks () {
+    for exe in "${1}"/bin/* "${1}"/jre/bin/*; do
+        if [ -x "${exe}" -a \
+	     ! -d "${exe}" -a \
+	     "`basename "${exe}"`" = "`basename "${exe}" .so`" -a \
+             ! -e "${PREFIX}/bin/`basename "${exe}"`" -a \
+             -w "${PREFIX}/bin" ]; then
+            ln -s "${PREFIX}/bin/javavm" \
+                "${PREFIX}/bin/`basename "${exe}"`" 2>/dev/null
+        fi
+    done
 }
 
+#
+# Sort the configuration file
+#
+sortConfiguration () {
+    if [ ! -f "${CONF}" ]; then
+        return
+    fi
+
+    if [ ! -w "${CONF}" -o ! -r "${CONF}" ]; then
+        echo "${IAM}: error: can't read/write ${CONF} configuration file!" >&2
+        return
+    fi
+
+    ifs="${IFS}"
+    IFS=:
+    cat "${CONF}" | \
+    (
+    export JAVAVMS
+    while read JAVAVM; do
+        VM=`echo "${JAVAVM}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+        # Check the VM actually exists
+        if [ ! -e "${VM}" ]; then
+            continue
+        fi
+        # Skip duplicate VMs
+        if [ ! -z "${JAVAVMS}" ]; then
+            for _JAVAVM in ${JAVAVMS}; do
+                if [ -z "${_JAVAVM}" ]; then
+                    continue
+                fi
+                _VM=`echo "${_JAVAVM}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+                if [ "x${VM}" = "x${_VM}" ]; then
+                    continue 2
+                fi
+            done
+        fi
+        VM=`dirname "${VM}"`
+        VM=`dirname "${VM}"`
+        VM=`basename "${VM}"`
+        _JAVAVMS=:
+        for _JAVAVM in ${JAVAVMS}; do
+            if [ -z "${_JAVAVM}" ]; then
+                continue
+            fi
+            if [ -z "${JAVAVM}" ]; then
+                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                continue
+            fi
+            _VM=`echo "${_JAVAVM}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+            _VM=`dirname "${_VM}"`
+            _VM=`dirname "${_VM}"`
+            _VM=`basename "${_VM}"`
+            VERSION=`echo ${VM} | sed -e 's|[^0-9]*||' 2>/dev/null`
+            _VERSION=`echo ${_VM} | sed -e 's|[^0-9]*||' 2>/dev/null`
+            if [ "${VERSION}" \> "${_VERSION}" ]; then
+                _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                JAVAVM=
+                continue
+            elif [ "${VERSION}" \< "${_VERSION}" ]; then
+                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                continue
+            else
+                case "${VM}" in
+                    diablo-jdk*)
+                        _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                        JAVAVM=
+                        continue
+                        ;;
+                    diablo-jre*|jdk*)
+                        case "${_VM}" in
+                            diablo*)
+                                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                                continue
+                                ;;
+                            *)
+                                _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                                JAVAVM=
+                                continue
+                                ;;
+                        esac
+                        ;;
+                    jre*|linux-sun-jdk*)
+                        case "${_VM}" in
+                            diablo*|j*)
+                                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                                continue
+                                ;;
+                            *)
+                                _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                                JAVAVM=
+                                continue
+                                ;;
+                        esac
+                        ;;
+                    linux-sun-jre*|linux-blackdown-jdk*)
+                        case "${_VM}" in
+                            diablo*|j*|linux-sun*)
+                                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                                continue
+                                ;;
+                            *)
+                                _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                                JAVAVM=
+                                continue
+                                ;;
+                        esac
+                        ;;
+                    linux-blackdown-jre*|linux-ibm-jdk*)
+                        case "${_VM}" in
+                            diablo*|j*|linux-sun*|linux-blackdown*)
+                                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+                                continue
+                                ;;
+                            *)
+                                _JAVAVMS="${_JAVAVMS}:${JAVAVM}:${_JAVAVM}"
+                                JAVAVM=
+                                continue
+                                ;;
+                        esac
+                        ;;
+                esac
+                _JAVAVMS="${_JAVAVMS}:${_JAVAVM}"
+            fi
+        done
+        JAVAVMS="${_JAVAVMS}"
+        if [ ! -z "${JAVAVM}" ]; then
+            JAVAVMS="${JAVAVMS}:${JAVAVM}"
+        fi
+    done;
+    if [ ! -z "${JAVAVMS}" ]; then
+        rm "${CONF}"
+        for JAVAVM in ${JAVAVMS}; do
+            if [ ! -z "${JAVAVM}" ]; then
+                echo "${JAVAVM}" >> "${CONF}"
+            fi
+        done
+    fi
+    )
+
+    IFS="${ifs}"
+}
+
+#
+# Check all of the VMs in the configuration file
+#
+checkVMs () {
+    # Sort the configuration.  This will also remove duplicates and
+    # non-existent VMs
+    sortConfiguration
+
+    # Ensure the configuration file exists
+    if [ ! -f "${CONF}" ]; then
+        exit 0
+    fi
+
+    # Ensure the configuration file has the correct permissions
+    if [ ! -w "${CONF}" -o ! -r "${CONF}" ]; then
+        echo "${IAM}: error: can't read/write ${CONF} configuration file!" 1>&2
+        exit 1
+    fi
+
+    # Ensure links are created for every executable for a VM.
+    cat "${CONF}" | \
+    (
+    while read JAVAVM; do
+        VM=`echo "${JAVAVM}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+        # Create symbolic links as appropriate if they don't exist.
+        JAVA_HOME=`dirname "${VM}"`
+        JAVA_HOME=`dirname "${JAVA_HOME}"`
+        createJavaLinks "${JAVA_HOME}"
+    done;
+    )
+
+    exit 0
+}
+
+#
+# Register a new Java VM.
+#
 registerVM () {
-    if [ x"${1}" = x"" ]; then
-       /bin/echo "Usage: ${IAM} path"
-       exit
+    # Check the java command given to us.
+    if [ -z "${1}" ]; then
+       echo "Usage: ${IAM} path"
+       exit 1
     fi
 
+    # Create the configuration file if it doesn't exist
     if [ ! -e "${CONF}" ]; then
-       /usr/bin/touch "${CONF}"
+       touch "${CONF}"
     fi
 
-    VM=`/bin/echo "${1}" | sed 's|#.*||'`
-    if [ ! -x ${VM} ]; then
-        /bin/echo "${IAM}: warning: the specified JavaVM \"${VM}\" either not exists or not executable" >&2
+    # Check that the given VM can be found in the configuration file
+    VM=`echo "${1}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+    if [ ! -z "`grep "${VM}" "${CONF}"`" ]; then
+        echo "${IAM}: error: JavaVM \"${VM}\" is already registered" 1>&2
+        exit 1
     fi
 
-    /bin/ed "${CONF}" >/dev/null <<EOF
-0a
-${1}
-.
-w
-q
-EOF
+    # Check that the VM exists and is executable
+    if [ ! -e "${VM}" ]; then
+        echo "${IAM}: error: JavaVM \"${VM}\" does not exist" 1>&2
+        exit 1
+    fi
+    if [ ! -x "${VM}" ]; then
+        echo "${IAM}: error: JavaVM \"${VM}\" is not executable" 1>&2
+        exit 1
+    fi
+
+    # Add the VM to the configuration file
+    echo "${1}" >> "${CONF}"
+
+    # Create symbolic links as appropriate if they don't exist.
+    JAVA_HOME=`dirname "${VM}"`
+    JAVA_HOME=`dirname "${JAVA_HOME}"`
+    createJavaLinks "${JAVA_HOME}"
+
+    # Sort the VMs
+    sortConfiguration
+
     exit 0
 }
 
+#
+# Unregister a Java VM.
+#
 unregisterVM () {
-    if [ x"${1}" = x"" ]; then
-       /bin/echo "Usage: ${IAM} path"
-       exit
+    # Check usage
+    if [ -z "${1}" ]; then
+       echo "Usage: ${IAM} path"
+       exit 1
     fi
 
+    # Check for the configuration file
     if [ ! -e "${CONF}" ]; then
-       /bin/echo "${IAM}: error: can't find ${CONF} config file!" >&2
+       echo "${IAM}: error: can't find ${CONF} configuration file!" >&2
        exit 1
     fi
 
-    if [ x"`grep ${1} ${CONF}`" = x"" ]; then
-        /bin/echo "${IAM}: error: \"${1}\" JavaVM is not currently registered"
+    # Check that the given VM can be found in the configuration file
+    if [ -z "`grep "${1}" "${CONF}"`" ]; then
+        echo "${IAM}: error: \"${1}\" JavaVM is not currently registered"
         exit 1
     fi
 
-    /bin/ed "${CONF}" >/dev/null <<EOF
+    # Remove unneeded symlinks
+    VMS=`sed -E 's|[[:space:]]*#.*||' < "${CONF}" | uniq 2>/dev/null`
+    VM=`grep "${1}" "${CONF}" | sed -E 's|[[:space:]]*#.*||' 2>/dev/null`
+    JAVA_HOME=`dirname "${VM}"`
+    JAVA_HOME=`dirname "${JAVA_HOME}"`
+    for exe in "${JAVA_HOME}"/bin/* "${JAVA_HOME}"/jre/bin/*; do
+        exe=`basename "${exe}"`
+        if [ -L "${PREFIX}/bin/${exe}" -a \
+             "`realpath "${PREFIX}/bin/${exe}" 2>/dev/null `" = \
+             "${PREFIX}/bin/javavm" ]; then
+            for JAVAVM in ${VMS}; do
+                if [ "${JAVAVM}" != "${VM}" ]; then
+                    JAVAVM=`dirname "${JAVAVM}"`
+                    JAVAVM=`dirname "${JAVAVM}"`
+                    if [ -x "${JAVAVM}/bin/${exe}" -o \
+                         -x "${JAVAVM}/jre/bin/${exe}" ]; then
+                        continue 2
+                    fi
+                fi
+            done
+
+            rm "${PREFIX}/bin/${exe}"
+        fi
+    done
+
+    # Remove the VM from the configuration file
+    ed "${CONF}" >/dev/null <<EOF
 g|${1}|d
 w
 q
 EOF
 
-    # Remove config file if its size reached 0
+    # Remove configuration file if its size reached 0
     if [ ! -s "${CONF}" ]; then
-        /bin/rm "${CONF}"
+        rm "${CONF}"
     fi
 
     exit 0
 }
 
+# Check for an alias and call the appropriate function.
 case "${IAM}" in
     registervm )
         registerVM "${1}"
@@ -93,29 +356,169 @@ case "${IAM}" in
     unregistervm )
         unregisterVM "${1}"
         ;;
+    checkvms )
+        checkVMs
+        ;;
 esac
 
 # Main ()
 
+# Backwards compatibility
+if [ "${IAM}" = "javavm" ]; then
+    echo "${IAM}: warning: The use of 'javavm' as a synonym for 'java' is deprecated" 1>&2
+    IAM=java
+fi
+
+# Use JAVA_HOME if its set in the environment
+if [ ! -z "${JAVA_HOME}" -a -x "${JAVA_HOME}/bin/${IAM}" ]; then
+    export JAVA_HOME
+    tryJavaCommand "${JAVA_HOME}/bin/${IAM}" "${@}"
+elif [ ! -z "${JAVA_HOME}" -a -x "${JAVA_HOME}/jre/bin/${IAM}" ]; then
+    export JAVA_HOME
+    tryJavaCommand "${JAVA_HOME}/jre/bin/${IAM}" "${@}"
+fi
+
 unset JAVA_HOME
 
-# First check if JAVAVM environment variable is set
-if [ x"${JAVAVM}" != x"" ]; then
-    tryrunVM "${JAVAVM}" "${@}"
+# Determine location of bsd.port.mk if it exists
+PORTSDIR=
+if [ -r /usr/share/mk/bsd.port.mk ]; then
+    PORTSDIR=`"${MAKE}" -f /usr/share/mk/bsd.port.mk -V PORTSDIR 2>/dev/null`
+fi
+
+BSD_PORT_MK=
+if [ ! -z "${PORTSDIR}" -a -r "${PORTSDIR}/Mk/bsd.port.mk" ]; then
+    BSD_PORT_MK="${PORTSDIR}/Mk/bsd.port.mk"
+fi
+
+# If bsd.port.mk was found, use that to determine the VM to use.
+if [ ! -z "${BSD_PORT_MK}" ]; then
+    JAVA_HOME=`"${MAKE}" -f "${BSD_PORT_MK}" -V JAVA_HOME USE_JAVA=yes 2>/dev/null`
+    if [ ! -z "${JAVA_HOME}" -a \
+         -x "${JAVA_HOME}/bin/${IAM}" ]; then
+        export JAVA_HOME
+        tryJavaCommand "${JAVA_HOME}/bin/${IAM}" "${@}"
+    elif [ ! -z "${JAVA_HOME}" -a \
+           -x "${JAVA_HOME}/jre/bin/${IAM}" ]; then
+        export JAVA_HOME
+        tryJavaCommand "${JAVA_HOME}/jre/bin/${IAM}" "${@}"
+    fi
 fi
 
 # Then try to make sure that ${CONF} exists
 if [ ! -e "${CONF}" ]; then
-    echo "${IAM}: error: can't find ${CONF} config file" >&2
+    echo "${IAM}: error: can't find ${CONF} configuration file" >&2
     exit 1
 fi
 
-# Allow coment in the ${CONF}
-VMS=`/usr/bin/sed 's|#.*||' < "${CONF}" | uniq`
+# Allow comments in the ${CONF}
+VMS=`sed -E 's|[[:space:]]*#.*||' < "${CONF}" | uniq 2>/dev/null`
+
+# Fix up JAVA_VERSION
+if [ ! -z "${JAVA_VERSION}" ]; then
+    VERSION=
+    for version in ${JAVA_VERSION}; do
+        case "${version}" in
+            1.1+)
+                VERSION="${VERSION} 1.1 1.2 1.3 1.4"
+                ;;
+            1.2+)
+                VERSION="${VERSION} 1.2 1.3 1.4"
+                ;;
+            1.3+)
+                VERSION="${VERSION} 1.3 1.4"
+                ;;
+            1.4+)
+                VERSION="${VERSION} 1.4"
+                ;;
+            *)
+                VERSION="${VERSION} ${version}"
+                ;;
+        esac
+    done
+    JAVA_VERSION=`echo "${VERSION}" | sort | uniq`
+fi
 
 # Finally try to run one of the ${VMS}
 for JAVAVM in ${VMS}; do
-    tryrunVM "${JAVAVM}" "${@}";
+    JAVA_HOME=`dirname "${JAVAVM}"`
+    JAVA_HOME=`dirname "${JAVA_HOME}"`
+    VM=`basename "${JAVA_HOME}"`
+    # Respect JAVA_VERSION
+    if [ ! -z "${JAVA_VERSION}" ]; then
+        VERSION=`echo ${VM} | \
+            sed -e 's|[^0-9]*\([0-9]\)\.\([0-9]\)\.[0-9]|\1.\2|'`
+        for version in ${JAVA_VERSION}; do
+            if [ "${VERSION}" = "${version}" ]; then
+                VERSION=
+                break
+            fi
+        done
+        if [ ! -z "${VERSION}" ]; then
+            continue
+        fi
+    fi
+    # Respect JAVA_OS
+    if [ ! -z "${JAVA_OS}" ]; then
+        OS=
+        case "${VM}" in
+            diablo*|j*)
+                OS=native
+                ;;
+            linux*)
+                OS=linux
+                ;;
+        esac
+        for os in ${JAVA_OS}; do
+            if [ "${OS}" = "${os}" ]; then
+                OS=
+                break
+            fi
+        done
+        if [ ! -z "${OS}" ]; then
+            continue
+        fi
+    fi
+    # Respect JAVA_VENDOR
+    if [ ! -z "${JAVA_VENDOR}" ]; then
+        VENDOR=
+        case "${VM}" in
+            diablo*)
+                VENDOR=bsdjava
+                ;;
+            j*)
+                VENDOR=freebsd
+                ;;
+            linux-blackdown*)
+                VENDOR=blackdown
+                ;;
+            linux-ibm*)
+                VENDOR=ibm
+                ;;
+            linux-sun*)
+                VENDOR=sun
+                ;;
+        esac
+        for vendor in ${JAVA_VENDOR}; do
+            if [ "${VENDOR}" = "${vendor}" ]; then
+                VENDOR=
+                break
+            fi
+        done
+        if [ ! -z "${VENDOR}" ]; then
+            continue
+        fi
+    fi
+    # Check if the command exists and try to run it.
+    if [ ! -z "${JAVA_HOME}" -a \
+         -x "${JAVA_HOME}/bin/${IAM}" ]; then
+        export JAVA_HOME
+        tryJavaCommand "${JAVA_HOME}/bin/${IAM}" "${@}"
+    elif [ ! -z "${JAVA_HOME}" -a \
+           -x "${JAVA_HOME}/jre/bin/${IAM}" ]; then
+        export JAVA_HOME
+        tryJavaCommand "${JAVA_HOME}/jre/bin/${IAM}" "${@}"
+    fi
 done
 
 echo "${IAM}: error: no suitable JavaVMs found" >&2