/usr/bin/jhindexer is in javahelp2 2.0.05.ds1-8.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 | #! /bin/sh
# This builds a search database
java -cp /usr/share/java/jhall.jar com.sun.java.help.search.Indexer "$@"
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