Unpacking large .ZIP archives

#! /bin/sh
 
TRUEZIP_JAR=truezip-samples-7.7.9-jar-with-dependencies.jar
 
if [ ! $# -eq 1 ]; then
    echo "Usage:"
    echo "  $0 [bambooCloudExportFile]"
    exit 1
fi
 
BAMBOO_EXPORT_FILE=$1
 
if [ ! -f $BAMBOO_EXPORT_FILE ]; then
    echo Can not access $BAMBOO_EXPORT_FILE
    exit 1
fi
 
if [ ! -f $TRUEZIP_JAR ]; then
    echo Downloading TrueZip JAR ...
    curl -s https://repo1.maven.org/maven2/de/schlichtherle/truezip/truezip-samples/7.7.9/$TRUEZIP_JAR -o $TRUEZIP_JAR
fi
 
if [ -d bamboo-home ]; then
    echo Directory bamboo-home exists, please remove it before proceeding
    exit 1
fi
 
if [ -d database ]; then
    echo Directory database exists, please remove it before proceeding
    exit 1
fi
 
echo Unzipping Bamboo HOME directory ...
java -jar $TRUEZIP_JAR cp $BAMBOO_EXPORT_FILE/bamboo-home bamboo-home
 
echo Unzipping Bamboo database ...
java -jar $TRUEZIP_JAR cp $BAMBOO_EXPORT_FILE/database database