Oracle v Google, CAFC (2014), at footnote 2:
The 37 API packages involved in this appeal are: java.awt.font, java.beans, java.io, java.lang, java.lang.annotation, java.lang.ref, java.lang.reflect, java.net, java.nio, java.nio.channels, java.nio.channels.spi, java.nio.charset, java.nio.charset.spi, java.security, java.security.acl, java.security.cert, java.security.interfaces, java.security.spec, java.sql, java.text, java.util, java.util.jar, java.util.logging, java.util.prefs, java.util.regex, java.util.zip, javax.crypto, javax.crypto.interfaces, javax.crypto.spec, javax.net, javax.net.ssl, javax.security.auth, javax.security.auth.callback, javax.security.auth.login, javax.security.auth.x500, javax.security.cert, and javax.sql.
The "declaring code and the structure, sequence, and organization of the API packages" is what Google took and what the CAFC held was entitled to copyright protection. This was composed of "over six hundred classes, with over six thousand methods".
Both sides acknowledged that "Google wrote its own implementing code".