jawa.fields module

class jawa.fields.Field(cf)

Bases: object

descriptor

The UTF8 Constant containing the field’s descriptor.

name

The UTF8 Constant containing the field’s name.

pack(out: IO)

Write the Field to the file-like object out.

Note

Advanced usage only. You will typically never need to call this method as it will be called for you when saving a ClassFile.

Parameters:out – Any file-like object providing write()

type

A JVMType representing the field’s type.

unpack(source: IO)

Read the Field from the file-like object fio.

Note

Advanced usage only. You will typically never need to call this method as it will be called for you when loading a ClassFile.

Parameters:source – Any file-like object providing read()

value

A shortcut for the field’s ConstantValue attribute, should one exist.

class jawa.fields.FieldTable(cf)

Bases: object

append(field: jawa.fields.Field)

create(name: str, descriptor: str, value: jawa.constants.Constant = None) → jawa.fields.Field

Creates a new field from name and descriptor. For example:

>>> from jawa.cf import ClassFile
>>> cf = ClassFile.create('BeerCounter')
>>> field = cf.fields.create('BeerCount', 'I')

To automatically create a static field, pass a value:

>>> from jawa.cf import ClassFile
>>> cf = ClassFile.create('BeerCounter')
>>> field = cf.fields.create(
...     'MaxBeer',
...     'I',
...     cf.constants.create_integer(99)
... )

Parameters:

• name – Name of the new field.
• descriptor – Type descriptor of the new field.
• value – Optional static value for the field.

find(*, name: str = None, type_: str = None, f: Callable = None) → Iterator[jawa.fields.Field]

Iterates over the fields table, yielding each matching method. Calling without any arguments is equivalent to iterating over the table.

Parameters:

• name – The name of the field(s) to find.
• type – The field descriptor (Ex: ‘I’)
• f – Any callable which takes one argument (the field).

find_and_remove(f: Callable)

Removes any and all fields for which f(field) returns True.

find_one(**kwargs) → Union[jawa.fields.Field, NoneType]

Same as find() but returns only the first result.

pack(out: IO)

Write the FieldTable to the file-like object out.

Note

Advanced usage only. You will typically never need to call this method as it will be called for you when saving a ClassFile.

Parameters:out – Any file-like object providing write()

remove(field: jawa.fields.Field)

Removes a Field from the table by identity.

unpack(source: IO)

Read the FieldTable from the file-like object source.

Note

Advanced usage only. You will typically never need to call this method as it will be called for you when loading a ClassFile.

Parameters:source – Any file-like object providing read()