Indonesian vs Javanese

Indonesian and Javanese both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indonesian	Yes	Yes	No	No
Javanese	Yes	Yes	No	No

As nouns, Javanese is a hyponym of Indonesian; that is, Javanese is a word with a more specific, narrower meaning than Indonesian:

Indonesian: the dialect of Malay used as the national language of the Republic of Indonesia or of Malaysia
Javanese: the Indonesian language spoken on Java

Other hyponyms of Indonesian include Javanese language, Sundanese, Sundanese language, Balinese, Balinese language.

As nouns, Javanese is a hyponym of Indonesian; that is, Javanese is a word with a more specific, narrower meaning than Indonesian:

Other hyponyms of Indonesian include Sumatran, Papuan, Javan.

Indonesian (noun)	Javanese (noun)
the dialect of Malay used as the national language of the Republic of Indonesia or of Malaysia	the Indonesian language spoken on Java
a native or inhabitant of Indonesia	a native or inhabitant of Java

Indonesian (adjective)	Javanese (adjective)
of or relating to or characteristic of Indonesia or its people or languages	of or relating to or characteristic of Java or its inhabitants or its language