通过bash脚本在Ubuntu 16.04上安装Java7

Question

I have below function java_install written in a bash script to install java on Linux box, to which I pass jdk-1.7.0_80-linux-x64.tgz as JAVA_PACKAGE . Now what is happening is java gets installed and works fine only within the script. Once I come out of this script, none of the java functionalities work, not even java -version . Could someone please help me on what I might be missing here? Basically, I just want java to be installed permanently on this box once this script is executed.

java_install() {
local JAVA_PACKAGE=$1
local TMPDIR=/tmp/quickstart
local TARGET=/usr/share
    if [ -n "$JAVA_PACKAGE" ] && [ -f "$JAVA_PACKAGE" ]; then
  rm -rf $TMPDIR
  mkdir -p $TMPDIR
  cp $JAVA_PACKAGE $TMPDIR
  ( cd $TMPDIR && tar fxz $JAVA_PACKAGE && rm $JAVA_PACKAGE )
  local JAVA_BASENAME=$(ls -1 $TMPDIR)
  mkdir -p $TARGET
  if [ -d "$TARGET/$JAVA_BASENAME" ]; then
    echo "# Java already installed at $TARGET/$JAVA_BASENAME"
    log_info "Java already installed at $TARGET/$JAVA_BASENAME"
  else
    echo "# Java now installed at $TARGET/$JAVA_BASENAME"
    log_info "Java now installed at $TARGET/$JAVA_BASENAME"
    mv $TMPDIR/$JAVA_BASENAME $TARGET
  fi
  rm -rf $TMPDIR

  # now create a script to export these settings
  export JAVA_HOME=$TARGET/$JAVA_BASENAME
  export PATH=$JAVA_HOME/bin:$PATH
else
  echo "# cannot find java package to install"
  log_error "cannot find java package to install"
fi
} 

Answer 1

Use update alternatives within your script to make your java installation available:

sudo update-alternatives --install "/usr/bin/java" "java" "path to you java executable" 1

More information on this topic can be found here: How to use the command update-alternatives --config java . Alternatively you can write the export commands for JAVA HOME and PATH to your .bashrc from within your script (if using bash). This way the modified variables are available in the bash shell.