There is that works for general mods. However, several partial solutions exist:
Conversely, a .mcaddon is simply a .zip file renamed, containing two folders: a (defining entities, items, blocks via JSON) and a Resource Pack (textures, sounds, models). Bedrock’s scripting is done in JavaScript (GameTests or Script API), which runs in a sandboxed environment with no direct memory or class manipulation. Therefore, no automated tool can read Java bytecode and emit a functional Bedrock add-on. The "conversion" is actually a complete rewrite .
is the gold standard for full mod conversion. For cosmetic changes, a simple file extension swap is the fastest, "portable" way to get the job done. using Blockbench? Convert JAR to ZIP Online | No Software Needed
Right-click on your .jar file, select "Rename," and change the extension from .jar to .zip . On some systems, you might need to enable the viewing of file extensions to do this.