7 lines
1.1 KiB
Markdown
7 lines
1.1 KiB
Markdown
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# Java Object Wrappers
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When the JS environment receives a Java object through a [bridge](BRIDGES.md), it is converted into a ```JavaObject```. A ```JavaObject``` cannot be used directly in the JS environment, but it can be stored and passed back to the Java environment using another [bridge](BRIDGES.md).
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To make interacting wit Java object easier, they are placed in a wrapper class. An example of a wrapper class is ```World```, it can be interacted with like any other JS object, but internally it uses its ```JavaObject``` to execute code in the Java environment.
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## Casting
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In Java, if you are given a ```LivingEntity```, you can use ```instanceof``` to check if it is a ```PlayerEntity``` and then cast it. However, because the JS environment only knows the class of the ```JavaObject```'s wrapper, it can't do this. However, you can manually cast a JS object wrapper to another wrapper type using the new wrapper type's constructor, like ```new PlayerEntity(livingEntity);```, if this operation is not possible (ie. The ```LivingEntity``` is not a ```PlayerEntity```), it will throw an ```Error```.
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