What everything imports

Verified against Minecraft 26.3 · Maps · The thirty most-imported Mojang classes: how many files name each one in an import statement.

One file in six imports BlockPos. That is the least surprising fact on this page; the next one is not. The chart counts Mojang imports only — net.minecraft and com.mojang — because the JDK’s List and the nullability annotation outrank everything on it and say nothing about the game. Under that rule the second most-imported type is not Minecraft’s: it is Codec, from Mojang’s DataFixerUpper library, imported by 943 files, with MapCodec sixth and RecordCodecBuilder seventh. Three of the seven classes the game most depends on are the serialisation vocabulary that turns objects into NBT and JSON and back, which is why Part II teaches codecs before anything a player can see.

Seven ideas, and where the book teaches them

The hubs are not thirty ideas; twenty-five of them are seven. The table below groups them, reading down the sixty rows rather than the thirty the figure draws, so that a family is not broken in half by the cut-off — ByteBufCodecs and PacketType are the wire’s vocabulary whether or not they clear it. So the table holds thirty-two names: twenty-five of the thirty, plus seven more from ranks 31 to 60 that their families would be incomplete without. The five of the thirty it leaves out are the two paragraphs after it, two and three.

Part II teaches three of the seven, Reference two, Part IX one, and the seventh — the world’s nouns — is the rest of the book. That is the more useful fact than Part II teaches the vocabulary: the classes a reader must know are not one part’s worth.

Two of the thirty belong to no family and get no row above, and neither does the first class after them; each is worth a look. Minecraft (284) is thirty-first, the first client-only class on the list and just outside the figure — the client’s hub is a hub for the client-only side alone, which is under a third of the files, and the shared seven tenths never name it. And Schema (404) and DSL (289) are the migration tree talking to itself: all but ten of the files that import Schema are in util/datafix, and the ten are its sibling util/filefix. One pair inside the table earns the same second look: ServerLevel (735) is imported by nearly as many files as Level (761), because most code that touches the world knows it is on the server and says so in its types.

The remaining three of the thirty have no row either. LogUtils (488) is Mojang’s logging library, the one line at the top of a class that keeps a logger. Util (457) is where the executors and the static odds and ends live (threads) — a hub because it is where the unclassifiable went, not because it is an idea. And BlockBehaviour (313) is the world’s nouns seen one class higher — the same one-class-higher shape what extends what draws for the Block tree.

What the count misses

An import is counted once per file, so the chart says how many files name the class, not how often. It also undercounts every class used inside its own package, because that needs no import: the 260 files that import Block are the files outside world/level/block that use it, and the same is true of BlockBehaviour and Minecraft. A class’s true reach is this number plus its package.

The table

Sixty rows, of which the figure draws thirty. side is which jar ships the class, or library for a class outside the decompile.

Rules: names, never code · how the system works, not how the code reads · newest version only · every backticked name passes tools/verify_names.py.