java:field

(java:field class-or-object "fieldName")

Reads a field: with a class-name string it reads a static field (such as a constant) -- an instance field named that way is an error -- and with a java object it reads that instance's field. Returns the marshalled value. Part of the JVM-only java interop package — available on the interpreter and in JVM-compiled classes, not on the WASM backend. See the Java interop guide.

The static constant Integer.MAX_VALUE is read and marshalled to a rontolisp integer.

Ending the form in :java-false, after the field name, answers Java's false as |false| rather than nil (the guide's Java's false back):

Ending it in :octets answers a byte[] field as an (unsigned-byte 8) vector of its octets (the guide's Octets back).