FWIW, you can do something like this, but it's not really what the OP
was looking for (this is the public methods of the RubyFile class we
use to implement File):
~ =E2=9E=94 ri --java org.jruby.RubyFile
--------------------------- Class: org.jruby.RubyFile < org.jruby.RubyIO
(no description...)
------------------------------------------------------------------------
Class methods:
--------------
absolute_path, atime, basename, chmod, chown, copy_stream,
createBasicObjectClass, createFileClass, createIOClass,
createObjectClass, ctime, dirname, expandUserPath, expand_path,
extname, failIfDirectory, file, fnmatch, foreach, foreach19, ftype,
getDirOrFileEntry, getFileEntry, getIOModes,
getIOModesIntFromString, getNewFileno, get_path, join, lchmod,
lchown, link, lstat, method_missing19, mtime, newIO, newInstance,
obliterateProcess, open, path, pipe, popen, popen3, popen4,
popenSpecial, print, putc, puts, read, read19, readlines, readlink,
realdirpath, realpath, rename, restartSystemCall, select,
select_static, singleton_method_added19,
singleton_method_removed19, singleton_method_undefined19, split,
stat, symlink, sysopen, truncate, truncate19, tryConvert, umask,
unlink, utime
Instance methods:
-----------------
addBlockingThread, addFinalizer, anyToString, asJavaString,
asString, atime, attachToObjectSpace, binmode, bytes, callInit,
callMethod, callSuper, chars19, checkArrayType, checkCallMethod,
checkStringType, checkStringType19, chmod, chown, close,
close_read, close_write, closed_p, compareTo, convertToArray,
convertToFloat, convertToHash, convertToInteger, convertToString,
convertToType, copyInstanceVariablesInto,
copySpecialInstanceVariables, ctime, ctl, dataGetStruct,
dataGetStructChecked, dataWrapStruct, display, dup, each19,
each_byte, each_byte19, each_char, each_char19, each_line,
each_line19, eof_p, eql, eql_p, equal_p, equal_p19, equals,
evalUnder, extend, external_encoding, fastGetInstanceVariable,
fastGetInternalVariable, fastHasInstanceVariable,
fastHasInternalVariable, fastSetInstanceVariable,
fastSetInternalVariable, fcntl, fileno, flock, flush, freeze,
frozen_p, fsync, getBlocking, getChannel, getClass,
getDescriptorByFileno, getEncoding, getFlag, getHandler,
getInStream, getInstanceVariable, getInstanceVariableList,
getInstanceVariableNameList, getInstanceVariables,
getInternalVariable, getInternalVariables, getJavaClass,
getMetaClass, getNativeTypeIndex, getOpenFile, getOutStream,
getPath, getRuntime, getSingletonClass, getType, getVariable,
getVariableCount, getVariableList, getVariableNameList, getc,
getline, gets, gets19, hasInstanceVariable, hasInternalVariable,
hasVariables, hash, hashCode, hashyInspect, id, id_deprecated,
infectBy, initialize, initialize19, initialize_copy, inspect,
instance_eval, instance_eval19, instance_exec, instance_exec19,
instance_of_p, instance_variable_defined_p, instance_variable_get,
instance_variable_set, instance_variables, instance_variables19,
internal_encoding, ioctl, isBuiltin, isClass, isClosed, isFalse,
isFrozen, isImmediate, isModule, isNil, isTaint, isTrue,
isUntrusted, kind_of_p, lchmod, lchown, lineno, lineno_set, lines,
lstat, makeMetaClass, method, methods, methods19, mtime, nil_p,
notify, notifyAll, op_append, op_binmode, op_cmp, op_eqq, op_equal,
op_equal_19, op_match, op_match19, op_not, op_not_equal,
op_not_match, path, pid, pos, pos_set, print, printf,
private_methods, private_methods19, protected_methods,
protected_methods19, public_methods, public_methods19, putc, puts,
rbClone, read, read_nonblock, readchar, readline, readlines,
readpartial, registerDescriptor, removeBlockingThread,
removeFinalizers, removeInstanceVariable, removeInternalVariable,
remove_instance_variable, reopen, respond_to_p, respond_to_p19,
respondsTo, rewind, seek, send, send19, setFlag, setFrozen,
setInstanceVariable, setInternalVariable, setMetaClass, setTaint,
setUntrusted, setVariable, set_encoding, singletonMethods,
singleton_methods, singleton_methods19, size, specificEval, stat,
sync, syncVariables, sync_set, sysread, sysseek, syswrite, taint,
tainted_p, toJava, toString, to_a, to_io, to_s, truncate, trust,
tty_p, type, type_deprecated, ungetc, unregisterDescriptor,
untaint, untrust, untrusted_p, wait, write, writeDataBuffered,
write_nonblock