Editing Java Edition Classic level format (section)

==Accessing the array of bytes==
The most interesting part of a level was the block array. Each byte in this array defined a [[Java Edition data values/Classic|block type]] at a corresponding location in the world. One generally had two options for accessing the byte array of blocks: 

The [[player]] could deserialize the compressed .dat file directly back into an instance of a Level object inside of Java, thus having access to the instance of the Level object in exactly the same way the Minecraft Server does. This would allow the player to set the blocks, dimensions, spawn point and other aspects of the map directly by calling the methods on the instantiated Level object. Manual decompression is not needed before loading, because Java can compress and decompress gzipped files on the fly. To load the datafile back into an instance of the Level class, the player would need the class definition for the Level class. This was included with the <samp>minecraft-server.jar</samp> file. An example of this could be seen in the [[Development resources/Example Minecraft Classic Level Editing Class]].

Others have read and modified the map's data by simply accessing the raw byte array in the datafile file. To do this, the player would decompress it, make changes to the bytes where the byte array is stored, and then compress it again. The 256x256x64 bytes (default dimensions) labeled blocks in each format were where the byte array was stored. The formula <code>65536 * y + 256 * z + x = Byte #</code> will convert Minecraft coordinates to the byte number in the array.

{{Java Edition}}

[[Category:Server]]

[[de:Spielstand-Speicherung/Classic Level Format]]
[[fr:Format de carte Classique]]
[[nl:Classic level formaat]]
[[pt:Formato de nível da Edição Java Classic]]
[[ru:Классический формат карт]]
[[zh:Classic世界格式]]