命令：
git log --format='%aN' | sort -u | while read name; do echo -en "$name\t"; git log --author="$name" --pretty=tformat: --numstat | grep "\(.java\)$" | awk '{ add += $1; subs += $2; loc += $1 - $2 } END { printf "added lines: %s, removed lines: %s, total lines: %s\n", add, subs, loc }' -; done