# Package javassist

package javassist
The Javassist Core API.

Javassist (Java programming assistant) makes bytecode engineering simple. It is a class library for editing bytecode in Java; it enables Java programs to define a new class at runtime and to modify a given class file when the JVM loads it.

The most significant class of this package is `CtClass`. See the description of this class first.

To know the version number of this package, type the following command:

    java -jar javassist.jar

It prints the version number on the console.

Related Packages
Package
Description
javassist.bytecode
Bytecode-level API.
javassist.expr
This package contains the classes for modifying a method body.
javassist.runtime
Runtime support classes required by modified bytecode.
javassist.tools
Covenient tools.
javassist.util
Utility classes.
Class
Description
ByteArrayClassPath
A `ByteArrayClassPath` contains bytes that is served as a class file to a `ClassPool`.
CannotCompileException
Thrown when bytecode transformation has failed.
ClassClassPath
A search-path for obtaining a class file by `getResourceAsStream()` in `java.lang.Class`.
ClassMap
A hash table associating class names with different names.
ClassPath
`ClassPath` is an interface implemented by objects representing a class search path.
ClassPool
A container of `CtClass` objects.
CodeConverter
Simple translator of method bodies (also see the `javassist.expr` package).
CodeConverter.ArrayAccessReplacementMethodNames
Interface containing the method names to be used as array access replacements.
CodeConverter.DefaultArrayAccessReplacementMethodNames
Default implementation of the `ArrayAccessReplacementMethodNames` interface giving default values for method names to be used for replacing accesses to array elements.
CtBehavior
`CtBehavior` represents a method, a constructor, or a static constructor (class initializer).
CtClass
An instance of `CtClass` represents a class.
CtConstructor
An instance of CtConstructor represents a constructor.
CtField
An instance of CtField represents a field.
CtField.Initializer
Instances of this class specify how to initialize a field.
CtMember
An instance of `CtMember` represents a field, a constructor, or a method.
CtMethod
An instance of `CtMethod` represents a method.
CtMethod.ConstParameter
Instances of this class represent a constant parameter.
CtNewConstructor
A collection of static methods for creating a `CtConstructor`.
CtNewMethod
A collection of static methods for creating a `CtMethod`.
CtPrimitiveType
An instance of `CtPrimitiveType` represents a primitive type.
Loader
The class loader for Javassist.
Loader.Simple
A simpler class loader.
LoaderClassPath
A class search-path representing a class loader.
Modifier
The Modifier class provides static methods and constants to decode class and member access modifiers.
NotFoundException
Signals that something could not be found.
SerialVersionUID
Utility for calculating serialVersionUIDs for Serializable classes.
Translator
An observer of `Loader`.
URLClassPath
A class search-path specified with URL (http).