setjdk shell function. This is what I've used in zsh, should work in bash too.

setjdk.sh

# Example usage:  setjdk 1.8
function setjdk {
  local ver=${1?Usage: setjdk <version>}

  export JAVA_HOME=$(/usr/libexec/java_home -v $ver)
  PATH=$(echo $PATH | tr ':' '\n' | grep -v Java | tr '\n' ':')
  export PATH=$JAVA_HOME/bin:$PATH
}