def __init__(self, source: IO = None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags(
'>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
def __init__(self, source: IO=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
def __init__(self, fio=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self._access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self._fields = FieldTable(self)
self._methods = MethodTable(self)
self._attributes = AttributeTable(self)
if fio:
self._from_io(fio)
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
>>> with open('HelloWorld.class', 'rb') as fin:
... cf = ClassFile(fin)
To save a newly created or modified ClassFile::
>>> cf = ClassFile.create('HelloWorld')
>>> with open('HelloWorld.class', 'wb') as out:
... cf.save(out)
:meth:`~ClassFile.create` sets up some reasonable defaults equivalent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param source: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, source: IO = None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags(
'>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
@classmethod
def create(cls,
this: str,
super_: str = u'java/lang/Object') -> 'ClassFile':
"""
A utility which sets up reasonable defaults for a new public class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf.this = cf.constants.create_class(this)
cf.super_ = cf.constants.create_class(super_)
return cf
def save(self, source: IO):
"""
Saves the class to the file-like object `source`.
:param source: Any file-like object providing write().
"""
write = source.write
write(
pack('>IHH', ClassFile.MAGIC, self.version.minor,
self.version.major))
self._constants.pack(source)
write(self.access_flags.pack())
write(
pack(f'>HHH{len(self._interfaces)}H', self._this, self._super,
len(self._interfaces), *self._interfaces))
self.fields.pack(source)
self.methods.pack(source)
self.attributes.pack(source)
def _from_io(self, source: IO):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = source.read
if unpack('>I', source.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', source.read(4))[::-1]
self._constants.unpack(source)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(f'>{interfaces_count}H',
read(2 * interfaces_count))
self.fields.unpack(source)
self.methods.unpack(source)
self.attributes.unpack(source)
@property
def version(self) -> ClassVersion:
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf = ClassFile.create('HelloWorld')
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, major_minor: Union[ClassVersion, Sequence]):
self._version = ClassVersion(*major_minor)
@property
def constants(self) -> ConstantPool:
"""
The :class:`~jawa.cp.ConstantPool` for this class.
"""
return self._constants
@property
def this(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this class.
"""
return self.constants.get(self._this)
@this.setter
def this(self, value):
self._this = value.index
@property
def super_(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this
class's superclass.
"""
return self.constants.get(self._super)
@super_.setter
def super_(self, value: ConstantClass):
self._super = value.index
@property
def interfaces(self) -> Iterable[ConstantClass]:
"""
A list of direct superinterfaces of this class as indexes into
the constant pool, in left-to-right order.
"""
return [self._constants[idx] for idx in self._interfaces]
@property
def bootstrap_methods(self) -> BootstrapMethod:
"""
Returns the bootstrap methods table from the BootstrapMethods attribute,
if one exists. If it does not, one will be created.
:returns: Table of `BootstrapMethod` objects.
"""
bootstrap = self.attributes.find_one(name='BootstrapMethods')
if bootstrap is None:
bootstrap = self.attributes.create(
ATTRIBUTE_CLASSES['BootstrapMethods'])
return bootstrap.table
def __repr__(self):
return f'<ClassFile(this={self.this.name.value!r})>'
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
from jawa import ClassFile
with open('HelloWorld.class') as fin:
cf = ClassFile(fin)
To save a newly created or modified ClassFile::
with open('HelloWorld.class', 'wb') as fout:
cf.save(fout)
To create a new ClassFile, use the helper :meth:`~ClassFile.create`::
from jawa import ClassFile
cf = ClassFile.create('HelloWorld')
with open('HelloWorld.class', 'wb') as fout:
cf.save(fout)
:meth:`~ClassFile.create` sets up some reasonable defaults equivelent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param fio: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, fio=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self._access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self._fields = FieldTable(self)
self._methods = MethodTable(self)
self._attributes = AttributeTable(self)
if fio:
self._from_io(fio)
@classmethod
def create(cls, this, super_='java/lang/Object'):
"""
A utility method which sets up reasonable defaults for a new public
class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf._this = cf.constants.create_class(this).index
cf._super = cf.constants.create_class(super_).index
return cf
def save(self, fout):
"""
Saves the class to the file-like object `fout`.
"""
write = fout.write
write(pack('>IHH',
ClassFile.MAGIC,
self.version.minor,
self.version.major
))
self._constants._to_io(fout)
write(self.access_flags.pack())
write(pack('>HHH{0}H'.format(len(self._interfaces)),
self._this,
self._super,
len(self._interfaces),
*self._interfaces
))
self._fields._to_io(fout)
self._methods._to_io(fout)
self._attributes._to_io(fout)
# ------------
# Internal
# ------------
def _from_io(self, fio):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = fio.read
if unpack('>I', fio.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', fio.read(4))[::-1]
self._constants._from_io(fio)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(
'>{0}H'.format(interfaces_count),
read(2 * interfaces_count)
)
self._fields._from_io(fio)
self._methods._from_io(fio)
self._attributes._from_io(fio)
# -------------
# Properties
# -------------
@property
def version(self):
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, (major, minor)):
self._version = ClassVersion(major, minor)
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
>>> with open('HelloWorld.class', 'rb') as fin:
... cf = ClassFile(fin)
To save a newly created or modified ClassFile::
>>> cf = ClassFile.create('HelloWorld')
>>> with open('HelloWorld.class', 'wb') as out:
... cf.save(out)
:meth:`~ClassFile.create` sets up some reasonable defaults equivalent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param source: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, source: IO=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
@classmethod
def create(cls, this: str, super_: str=u'java/lang/Object') -> 'ClassFile':
"""
A utility which sets up reasonable defaults for a new public class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf.this = cf.constants.create_class(this)
cf.super_ = cf.constants.create_class(super_)
return cf
def save(self, source: IO):
"""
Saves the class to the file-like object `source`.
:param source: Any file-like object providing write().
"""
write = source.write
write(pack(
'>IHH',
ClassFile.MAGIC,
self.version.minor,
self.version.major
))
self._constants.pack(source)
write(self.access_flags.pack())
write(pack(
f'>HHH{len(self._interfaces)}H',
self._this,
self._super,
len(self._interfaces),
*self._interfaces
))
self.fields.pack(source)
self.methods.pack(source)
self.attributes.pack(source)
def _from_io(self, source: IO):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = source.read
if unpack('>I', source.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', source.read(4))[::-1]
self._constants.unpack(source)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(
f'>{interfaces_count}H',
read(2 * interfaces_count)
)
self.fields.unpack(source)
self.methods.unpack(source)
self.attributes.unpack(source)
@property
def version(self) -> ClassVersion:
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf = ClassFile.create('HelloWorld')
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, major_minor: Union[ClassVersion, Sequence]):
self._version = ClassVersion(*major_minor)
@property
def constants(self) -> ConstantPool:
"""
The :class:`~jawa.cp.ConstantPool` for this class.
"""
return self._constants
@property
def this(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this class.
"""
return self.constants.get(self._this)
@this.setter
def this(self, value):
self._this = value.index
@property
def super_(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this
class's superclass.
"""
return self.constants.get(self._super)
@super_.setter
def super_(self, value: ConstantClass):
self._super = value.index
@property
def interfaces(self) -> Iterable[ConstantClass]:
"""
A list of direct superinterfaces of this class as indexes into
the constant pool, in left-to-right order.
"""
return [self._constants[idx] for idx in self._interfaces]
@property
def bootstrap_methods(self) -> BootstrapMethod:
"""
Returns the bootstrap methods table from the BootstrapMethods attribute,
if one exists. If it does not, one will be created.
:returns: Table of `BootstrapMethod` objects.
"""
bootstrap = self.attributes.find_one(name='BootstrapMethods')
if bootstrap is None:
bootstrap = self.attributes.create(
ATTRIBUTE_CLASSES['BootstrapMethods']
)
return bootstrap.table
def __repr__(self):
return f'<ClassFile(this={self.this.name.value!r})>'