org.modeshape.sequencer.mp3

Class Mp3MetadataSequencer

java.lang.Object

org.modeshape.jcr.api.sequencer.Sequencer

org.modeshape.sequencer.mp3.Mp3MetadataSequencer

public class Mp3MetadataSequencer
extends Sequencer

A sequencer that processes the binary content of an MP3 audio file, extracts the metadata for the file, and then writes that audio metadata to the repository.

This sequencer produces data that corresponds to the following structure:

• mp3:metadata node of type mp3:metadata
  • mp3:title - optional string property for the name of the audio file or recording
  • mp3:author - optional string property for the author of the recording
  • mp3:album - optional string property for the name of the album
  • mp3:year - optional integer property for the year the recording as created
  • mp3:comment - optional string property specifying a comment

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Mp3MetadataSequencer.MimeTypeConstants

Nested classes/interfaces inherited from class org.modeshape.jcr.api.sequencer.Sequencer

Sequencer.Context

Constructor Summary

Constructors

Constructor and Description
Mp3MetadataSequencer()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	execute(Property inputProperty, Node outputNode, Sequencer.Context context) Execute the sequencing operation on the specified property, which has recently been created or changed.
void	initialize(NamespaceRegistry registry, NodeTypeManager nodeTypeManager) Initialize the sequencer.

Methods inherited from class org.modeshape.jcr.api.sequencer.Sequencer

getAcceptedMimeTypes, getLogger, getName, getPathExpressions, getRepositoryName, getUniqueId, hasAcceptedMimeTypes, isAccepted, registerDefaultMimeTypes, registerNamespace, registerNodeTypes, registerNodeTypes, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Mp3MetadataSequencer

public Mp3MetadataSequencer()

Method Detail

initialize

public void initialize(NamespaceRegistry registry,
              NodeTypeManager nodeTypeManager)
                throws RepositoryException,
                       IOException

Description copied from class: Sequencer

Initialize the sequencer. This is called automatically by ModeShape once for each Sequencer instance, and should not be called by the sequencer.

By default this method does nothing, so it should be overridden by implementations to do a one-time initialization of any internal components. For example, sequencers can use the supplied registry and nodeTypeManager objects to register custom namesapces and node types required by the generated content.

Overrides:

initialize in class Sequencer

Parameters:

registry - the namespace registry that can be used to register custom namespaces; never null

nodeTypeManager - the node type manager that can be used to register custom node types; never null

Throws:

RepositoryException - if operations on the NamespaceRegistry or NodeTypeManager fail

IOException - if any stream based operations fail (like importing cnd files)

execute

public boolean execute(Property inputProperty,
              Node outputNode,
              Sequencer.Context context)
                throws Exception

Description copied from class: Sequencer

Execute the sequencing operation on the specified property, which has recently been created or changed.

Each sequencer is expected to process the value of the property, extract information from the value, and write a structured representation (in the form of a node or a subgraph of nodes) using the supplied output node. Note that the output node will either be:

1. the selected node, in which case the sequencer was configured to generate the output information directly under the selected input node; or
2. a newly created node in a different location than node being sequenced (in this case, the primary type of the new node will be 'nt:unstructured', but the sequencer can easily change that using Node.setPrimaryType(String))

The implementation is expected to always clean up all resources that it acquired, even in the case of exceptions.

Note: This method must be threadsafe: ModeShape will likely invoke this method concurrently in separate threads, and the method should never modify the state or fields of the Sequencer implementation class. All initialization should be performed in Sequencer.initialize(NamespaceRegistry, NodeTypeManager).

Specified by:

execute in class Sequencer

Parameters:

inputProperty - the property that was changed and that should be used as the input; never null

outputNode - the node that represents the output for the derived information; never null, and will either be new if the output is being placed outside of the selected node, or will not be new when the output is to be placed on the selected input node

context - the context in which this sequencer is executing, and which may contain additional parameters useful when generating the output structure; never null

Returns:

true if the sequencer's output should be saved, or false otherwise

Throws:

Exception - if there was a problem with the sequencer that could not be handled. All exceptions will be logged automatically as errors by ModeShape.