@@ -955,6 +955,9 @@ Removed
   ``SSTATE_INTERNED_IMMORTAL`` macro.
   (Contributed by Victor Stinner in :gh:`85858`.)
 
+* Remove ``Jython`` compatibility hacks from several stdlib modules and tests.
+  (Contributed by Nikita Sobolev in :gh:`99482`.)
+
 * Remove ``_use_broken_old_ctypes_structure_semantics_`` flag
   from :mod:`ctypes` module.
   (Contributed by Nikita Sobolev in :gh:`99285`.)
@@ -56,11 +56,6 @@ class Error(Exception):
     pass
 error = Error   # backward compatibility
 
-try:
-    from org.python.core import PyStringMap
-except ImportError:
-    PyStringMap = None
-
 __all__ = ["Error", "copy", "deepcopy"]
 
 def copy(x):
@@ -120,9 +115,6 @@ def _copy_immutable(x):
 d[set] = set.copy
 d[bytearray] = bytearray.copy
 
-if PyStringMap is not None:
-    d[PyStringMap] = PyStringMap.copy
-
 del d, t
 
 def deepcopy(x, memo=None, _nil=[]):
@@ -231,8 +223,6 @@ def _deepcopy_dict(x, memo, deepcopy=deepcopy):
         y[deepcopy(key, memo)] = deepcopy(value, memo)
     return y
 d[dict] = _deepcopy_dict
-if PyStringMap is not None:
-    d[PyStringMap] = _deepcopy_dict
 
 def _deepcopy_method(x, memo): # Copy instance methods
     return type(x)(x.__func__, deepcopy(x.__self__, memo))
@@ -301,4 +291,4 @@ def _reconstruct(x, memo, func, args,
                 y[key] = value
     return y
 
-del types, weakref, PyStringMap
+del types, weakref
@@ -98,12 +98,6 @@ class _Stop(Exception):
     def __init__(self, value):
         self.value = value
 
-# Jython has PyStringMap; it's a dict subclass with string keys
-try:
-    from org.python.core import PyStringMap
-except ImportError:
-    PyStringMap = None
-
 # Pickle opcodes.  See pickletools.py for extensive docs.  The listing
 # here is in kind-of alphabetical order of 1-character pickle code.
 # pickletools groups them by purpose.
@@ -972,8 +966,6 @@ def save_dict(self, obj):
         self._batch_setitems(obj.items())
 
     dispatch[dict] = save_dict
-    if PyStringMap is not None:
-        dispatch[PyStringMap] = save_dict
 
     def _batch_setitems(self, items):
         # Helper to batch up SETITEMS sequences; proto >= 1 only
 
@@ -1290,7 +1290,7 @@ def platform(aliased=0, terse=0):
         else:
             platform = _platform(system, release, version, csd)
 
-    elif system in ('Linux',):
+    elif system == 'Linux':
         # check for libc vs. glibc
         libcname, libcversion = libc_ver()
         platform = _platform(system, release, machine, processor,
 
@@ -404,12 +404,7 @@ def setquit():
 def setcopyright():
     """Set 'copyright' and 'credits' in builtins"""
     builtins.copyright = _sitebuiltins._Printer("copyright", sys.copyright)
-    if sys.platform[:4] == 'java':
-        builtins.credits = _sitebuiltins._Printer(
-            "credits",
-            "Jython is maintained by the Jython developers (www.jython.org).")
-    else:
-        builtins.credits = _sitebuiltins._Printer("credits", """\
+    builtins.credits = _sitebuiltins._Printer("credits", """\
     Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
     for supporting Python development.  See www.python.org for more information.""")
     files, dirs = [], []
 
@@ -505,6 +505,7 @@ def requires_debug_ranges(reason='requires co_positions / debug_ranges'):
 requires_legacy_unicode_capi = unittest.skipUnless(unicode_legacy_string,
                         'requires legacy Unicode C API')
 
+# Is not actually used in tests, but is kept for compatibility.
 is_jython = sys.platform.startswith('java')
 
 is_android = hasattr(sys, 'getandroidapilevel')
@@ -736,8 +737,6 @@ def gc_collect():
     """
     import gc
     gc.collect()
-    if is_jython:
-        time.sleep(0.1)
     gc.collect()
     gc.collect()
 
 
@@ -11,11 +11,7 @@
 
 
 # Filename used for testing
-if os.name == 'java':
-    # Jython disallows @ in module names
-    TESTFN_ASCII = '$test'
-else:
-    TESTFN_ASCII = '@test'
+TESTFN_ASCII = '@test'
 
 # Disambiguate TESTFN for parallel testing, while letting it remain a valid
 # module name.
 
@@ -100,10 +100,9 @@ def test_all(self):
             '__future__',
         ])
 
-        if not sys.platform.startswith('java'):
-            # In case _socket fails to build, make this test fail more gracefully
-            # than an AttributeError somewhere deep in CGIHTTPServer.
-            import _socket
+        # In case _socket fails to build, make this test fail more gracefully
+        # than an AttributeError somewhere deep in CGIHTTPServer.
+        import _socket
 
         ignored = []
         failed_imports = []
 
@@ -2,47 +2,18 @@
    Test cases for codeop.py
    Nick Mathewson
 """
-import sys
 import unittest
 import warnings
-from test import support
 from test.support import warnings_helper
 
 from codeop import compile_command, PyCF_DONT_IMPLY_DEDENT
-import io
-
-if support.is_jython:
-
-    def unify_callables(d):
-        for n,v in d.items():
-            if hasattr(v, '__call__'):
-                d[n] = True
-        return d
 
 class CodeopTests(unittest.TestCase):
 
     def assertValid(self, str, symbol='single'):
         '''succeed iff str is a valid piece of code'''
-        if support.is_jython:
-            code = compile_command(str, "<input>", symbol)
-            self.assertTrue(code)
-            if symbol == "single":
-                d,r = {},{}
-                saved_stdout = sys.stdout
-                sys.stdout = io.StringIO()
-                try:
-                    exec(code, d)
-                    exec(compile(str,"<input>","single"), r)
-                finally:
-                    sys.stdout = saved_stdout
-            elif symbol == 'eval':
-                ctx = {'a': 2}
-                d = { 'value': eval(code,ctx) }
-                r = { 'value': eval(str,ctx) }
-            self.assertEqual(unify_callables(r),unify_callables(d))
-        else:
-            expected = compile(str, "<input>", symbol, PyCF_DONT_IMPLY_DEDENT)
-            self.assertEqual(compile_command(str, "<input>", symbol), expected)
+        expected = compile(str, "<input>", symbol, PyCF_DONT_IMPLY_DEDENT)
+        self.assertEqual(compile_command(str, "<input>", symbol), expected)
 
     def assertIncomplete(self, str, symbol='single'):
         '''succeed iff str is the start of a valid piece of code'''
@@ -62,16 +33,12 @@ def test_valid(self):
         av = self.assertValid
 
         # special case
-        if not support.is_jython:
-            self.assertEqual(compile_command(""),
-                             compile("pass", "<input>", 'single',
-                                     PyCF_DONT_IMPLY_DEDENT))
-            self.assertEqual(compile_command("\n"),
-                             compile("pass", "<input>", 'single',
-                                     PyCF_DONT_IMPLY_DEDENT))
-        else:
-            av("")
-            av("\n")
+        self.assertEqual(compile_command(""),
+                            compile("pass", "<input>", 'single',
+                                    PyCF_DONT_IMPLY_DEDENT))
+        self.assertEqual(compile_command("\n"),
+                            compile("pass", "<input>", 'single',
+                                    PyCF_DONT_IMPLY_DEDENT))
 
         av("a = 1")
         av("\na = 1")
 
@@ -360,10 +360,9 @@ def test_capi3():
             self.assertRaises(SystemError, _testcapi.raise_exception,
                               InvalidException, 1)
 
-        if not sys.platform.startswith('java'):
-            test_capi1()
-            test_capi2()
-            test_capi3()
+        test_capi1()
+        test_capi2()
+        test_capi3()
 
     def test_WindowsError(self):
         try: