org.python.core

Class BytecodeLoader

java.lang.Object

org.python.core.BytecodeLoader

public class BytecodeLoader
extends Object

Utility class for loading compiled python modules and java classes defined in python modules.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BytecodeLoader.Loader

Constructor Summary

Constructors

Constructor and Description
BytecodeLoader()

Method Summary

Modifier and Type	Method and Description
static void	fixPyBytecode(Class<? extends ContainsPyBytecode> c) This method looks for Python-Bytecode stored in String literals.
static Class<?>	makeClass(String name, byte[] data, Class<?>... referents) Turn the java byte code in data into a java class.
static Class<?>	makeClass(String name, List<Class<?>> referents, byte[] data) Turn the java byte code in data into a java class.
static PyCode	makeCode(String name, byte[] data, String filename) Turn the java byte code for a compiled python module into a java class.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BytecodeLoader

public BytecodeLoader()

Method Detail

makeClass

public static Class<?> makeClass(String name,
                                 byte[] data,
                                 Class<?>... referents)

Turn the java byte code in data into a java class.

Parameters:

name - the name of the class

data - the java byte code.

referents - superclasses and interfaces that the new class will reference.

makeClass

public static Class<?> makeClass(String name,
                                 List<Class<?>> referents,
                                 byte[] data)

Turn the java byte code in data into a java class.

Parameters:

name - the name of the class

referents - superclasses and interfaces that the new class will reference.

data - the java byte code.

fixPyBytecode

public static void fixPyBytecode(Class<? extends ContainsPyBytecode> c)
                          throws IllegalAccessException,
                                 NoSuchFieldException,
                                 IOException,
                                 ClassNotFoundException

This method looks for Python-Bytecode stored in String literals. While Java supports rather long strings, constrained only by int-addressing of arrays, it supports only up to 65535 characters in literals (not sure how escape-sequences are counted). To circumvent this limitation, the code is automatically splitted into several literals with the following naming-scheme. - The marker-interface 'ContainsPyBytecode' indicates that a class contains (static final) literals of the following scheme: - a prefix of '___' indicates a bytecode-containing string literal - a number indicating the number of parts follows - '0_' indicates that no splitting occurred - otherwise another number follows, naming the index of the literal - indexing starts at 0 Examples: ___0_method1 contains bytecode for method1 ___2_0_method2 contains first part of method2's bytecode ___2_1_method2 contains second part of method2's bytecode Note that this approach is provisional. In future, Jython might contain the bytecode directly as bytecode-objects. The current approach was feasible with much less complicated JVM bytecode-manipulation, but needs special treatment after class-loading.

Throws:

IllegalAccessException

NoSuchFieldException

IOException

ClassNotFoundException

makeCode

public static PyCode makeCode(String name,
                              byte[] data,
                              String filename)

Turn the java byte code for a compiled python module into a java class.

Parameters:

name - the name of the class

data - the java byte code.