I think theres a tool to convert a world to bedrock, then one to convert to java

there some tools but they don't work well sometimes, try some of them maybe you will get lucky

Universal Minecraft Tool Yes it does. I have tested myself with an outdated tool. I converted a Java world to Wii U version. However, Any items you putted in the chest or in inventory will not appear.

There's a free oudated tool called MCC Tool Chest for Legacy + Java. My only problem is that it doesn't let us trim any parts of a Java map. It trims the spawn point environment. Universal MC Converter :Pricey but all features needed. MCCToolChest : Free but missing features...

Here's an example of a Java World converted to Wii U version I did a long time ago.It was also thanks to Nobledez. I used MCCToolChest