Implementing the ArchiveHandler Interface

An archive handler is responsible for handling the particular layout of an archive. Java EE defines a set of archives (WAR, JAR, and RAR, for example), and each of these archives has an ArchiveHandler instance associated with the archive type.

Each layout should have one handler associated with it. There is no extension point support at this level; the archive handler's responsibility is to give access to the classes and resources packaged in the archive, and it should not contain any container-specific code. The java.lang.ClassLoader returned by the handler is used by all the containers in which the application will be deployed.

ArchiveHandler defines the following methods:

getArchiveType()

Returns the name of the archive type as a String. Typically, this is the archive extension, such as jar or war.

getDefaultApplicationName(ReadableArchive archive)

Returns the default name of the specified archive as a String. Typically this default name is the name part of the URI location of the archive.

handles(ReadableArchive archive)

Returns a boolean value indicating whether this implementation of ArchiveHandler can work with the specified archive.

getClassLoader(DeploymentContext dc)

Returns a java.lang.ClassLoader capable of loading all classes from the archive passed in by the DeploymentContext instance. Typically the ClassLoader will load classes in the scratch directory area, returned by DeploymentContext.getScratchDir(), as stubs and other artifacts are generated in the scratch directory.

expand(ReadableArchive source, WritableArchive target)

Prepares the ReadableArchivesource archive for loading into the container in a format the container accepts. Such preparation could be to expand a compressed archive, or possibly nothing at all if the source archive format is already in a state that the container can handle. This method returns the archive as an instance of WritableArchive.