Though there does not seem to be an hgignore.io, you canuse any ignore file generated by gitignore.io by simply placing syntax: glob on the first line.
.hgignore
syntax: glob
# Created by https://www.gitignore.io/api/java,eclipse,netbeans,intellij
### Eclipse ###
.metadata
bin/
tmp/
*.tmp
...
Though there does not seem to be an hgignore.io, you can use any ignore file generated by gitignore.io by simply placing
.hgignoresyntax: globon the first line.More info about
.hgignorefiles.