Package org.alfresco.repo.content.metadata

Class AbstractMappingMetadataExtracter

java.lang.Object
org.alfresco.repo.content.metadata.AbstractMappingMetadataExtracter
All Implemented Interfaces:
ContentWorker, MetadataEmbedder, MetadataExtracter, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware, org.springframework.context.ApplicationContextAware
Direct Known Subclasses:
AsynchronousExtractor, RFC822MetadataExtracter, XmlMetadataExtracter, XPathMetadataExtracter
@AlfrescoPublicApi public abstract class AbstractMappingMetadataExtracter extends Object implements MetadataExtracter, MetadataEmbedder, org.springframework.beans.factory.BeanNameAware, org.springframework.context.ApplicationContextAware
Support class for metadata extracters that support dynamic and config-driven mapping between extracted values and model properties. Extraction is broken up into two phases:
  • Extract ALL available metadata from the document.
  • Translate the metadata into system properties.

Migrating an existing extracter to use this class is straightforward:

Since:
2.1
Author:
Jesper Steen Møller, Derek Hulley
See Also:

  • Field Details

  • Constructor Details

    • AbstractMappingMetadataExtracter

      protected AbstractMappingMetadataExtracter()
      Default constructor. If this is called, then isSupported(String) should be implemented. This is useful when the list of supported mimetypes is not known when the instance is constructed. Alternatively, once the set becomes known, call setSupportedMimetypes(Collection).
      See Also:

    • AbstractMappingMetadataExtracter

      protected AbstractMappingMetadataExtracter(Set<String> supportedMimetypes)
      Constructor that can be used when the list of supported mimetypes is known up front.
      Parameters:
      supportedMimetypes - the set of mimetypes supported by default

    • AbstractMappingMetadataExtracter

      protected AbstractMappingMetadataExtracter(Set<String> supportedMimetypes, Set<String> supportedEmbedMimetypes)
      Constructor that can be used when the list of supported extract and embed mimetypes is known up front.
      Parameters:
      supportedMimetypes - the set of mimetypes supported for extraction by default
      supportedEmbedMimetypes - the set of mimetypes supported for embedding by default

  • Method Details

    • setRegistry

      public void setRegistry(MetadataExtracterRegistry registry)
      Set the registry to register with. If this is not set, then the default initialization will not auto-register the extracter for general use. It can still be used directly.
      Parameters:
      registry - a metadata extracter registry

    • setMimetypeService

      public void setMimetypeService(MimetypeService mimetypeService)
      Parameters:
      mimetypeService - the mimetype service. Set this if required.

    • getMimetypeService

      protected MimetypeService getMimetypeService()
      Returns:
      Returns the mimetype helper

    • setDictionaryService

      public void setDictionaryService(DictionaryService dictionaryService)
      Parameters:
      dictionaryService - the dictionary service to determine which data conversions are necessary

    • getSupportedMimetypes

      public Set<String> getSupportedMimetypes()

    • setSupportedMimetypes

      public void setSupportedMimetypes(Collection<String> supportedMimetypes)
      Set the mimetypes that are supported by the extracter.

    • setSupportedEmbedMimetypes

      public void setSupportedEmbedMimetypes(Collection<String> supportedEmbedMimetypes)
      Set the mimetypes that are supported for embedding.

    • isSupported

      public boolean isSupported(String sourceMimetype)
      Determines if the extracter works against the given mimetype.
      Specified by:
      isSupported in interface MetadataExtracter
      Parameters:
      sourceMimetype - the document mimetype
      Returns:
      Returns true if the mimetype is supported, otherwise false.
      See Also:

    • isEmbeddingSupported

      public boolean isEmbeddingSupported(String sourceMimetype)
      Determines if the extracter works against the given mimetype.
      Specified by:
      isEmbeddingSupported in interface MetadataEmbedder
      Parameters:
      sourceMimetype - the document mimetype
      Returns:
      Returns true if the mimetype is supported, otherwise false.
      See Also:

    • isEnabled

      protected boolean isEnabled(String mimetype)

    • setOverwritePolicy

      public void setOverwritePolicy(MetadataExtracter.OverwritePolicy overwritePolicy)
      Set the policy to use when existing values are encountered. Depending on how the extractor is called, this may not be relevant, i.e an empty map of existing properties may be passed in by the client code, which may follow its own overwrite strategy.
      Parameters:
      overwritePolicy - the policy to apply when there are existing system properties

    • setFailOnTypeConversion

      public void setFailOnTypeConversion(boolean failOnTypeConversion)
      Set whether the extractor should discard metadata that fails to convert to the target type defined in the data dictionary model. This is true by default i.e. if the data extracted is not compatible with the target model then the extraction will fail. If this is false then any extracted data that fails to convert will be discarded.
      Parameters:
      failOnTypeConversion - false to discard properties that can't get converted to the dictionary-defined type, or true (default) to fail the extraction if the type doesn't convert

    • setSupportedDateFormats

      public void setSupportedDateFormats(List<String> supportedDateFormats)
      Set the date formats, over and above the ISO8601 format, that will be supported for string to date conversions. The supported syntax is described by the SimpleDateFormat Javadocs.
      Parameters:
      supportedDateFormats - a list of supported date formats.

    • setInheritDefaultMapping

      public void setInheritDefaultMapping(boolean inheritDefaultMapping)
      Set if the property mappings augment or override the mapping generically provided by the extracter implementation. The default is false, i.e. any mapping set completely replaces the default mappings.

      Note that even when set to true an individual property mapping entry replaces the entry provided by the extracter implementation.

      Parameters:
      inheritDefaultMapping - true to add the configured mapping to the list of default mappings.
      See Also:

    • setBeanName

      public void setBeanName(String beanName)
      Specified by:
      setBeanName in interface org.springframework.beans.factory.BeanNameAware

    • getBeanName

      public String getBeanName()

    • setApplicationContext

      public void setApplicationContext(org.springframework.context.ApplicationContext applicationContext)
      Specified by:
      setApplicationContext in interface org.springframework.context.ApplicationContextAware

    • setProperties

      public void setProperties(Properties properties)
      The Alfresco global properties.

    • setEnableStringTagging

      public void setEnableStringTagging(boolean enableStringTagging)
      Whether or not to enable the pass through of simple strings to cm:taggable tags
      Parameters:
      enableStringTagging - true find or create tags for each string mapped to cm:taggable. false (default) ignore mapping strings to tags.

    • setInheritDefaultEmbedMapping

      public void setInheritDefaultEmbedMapping(boolean inheritDefaultEmbedMapping)
      Set if the embed property mappings augment or override the mapping generically provided by the extracter implementation. The default is false, i.e. any mapping set completely replaces the default mappings.

      Note that even when set to true an individual property mapping entry replaces the entry provided by the extracter implementation.

      Parameters:
      inheritDefaultEmbedMapping - true to add the configured embed mapping to the list of default embed mappings.
      See Also:

    • setMimetypeLimits

      public void setMimetypeLimits(Map<String,MetadataExtracterLimits> mimetypeLimits)
      Sets the map of source mimetypes to metadata extracter limits.

    • getExecutorService

      protected ExecutorService getExecutorService()
      Gets the ExecutorService to be used for timeout-aware extraction.

      If no ExecutorService has been defined a default of Executors.newCachedThreadPool() is used during init().

      Returns:
      the defined or default ExecutorService

    • setExecutorService

      public void setExecutorService(ExecutorService executorService)
      Sets the ExecutorService to be used for timeout-aware extraction.
      Parameters:
      executorService - the ExecutorService for timeouts

    • setMapping

      public void setMapping(Map<String,Set<QName>> mapping)
      Set the mapping from document metadata to system metadata. It is possible to direct an extracted document property to several system properties. The conversion between the document property types and the system property types will be done by the default converter.
      Parameters:
      mapping - a mapping from document metadata to system metadata

    • setEmbedMapping

      public void setEmbedMapping(Map<QName,Set<String>> embedMapping)
      Set the embed mapping from document metadata to system metadata. It is possible to direct an model properties to several content file metadata keys. The conversion between the model property types and the content file metadata keys types will be done by the default converter.
      Parameters:
      embedMapping - an embed mapping from model properties to content file metadata keys

    • setMappingProperties

      public void setMappingProperties(Properties mappingProperties)
      Set the properties that contain the mapping from document metadata to system metadata. This is an alternative to the setMapping(Map) method. Any mappings already present will be cleared out. The property mapping is of the form: 
       # Namespaces prefixes
 namespace.prefix.cm=http://www.alfresco.org/model/content/1.0
 namespace.prefix.my=http://www....com/alfresco/1.0
 
 # Mapping
 editor=cm:author, my:editor
 title=cm:title
 user1=cm:summary
 user2=cm:description
      The mapping can therefore be from a single document property onto several system properties.
      Parameters:
      mappingProperties - the properties that map document properties to system properties

    • setEmbedMappingProperties

      public void setEmbedMappingProperties(Properties embedMappingProperties)
      Set the properties that contain the embed mapping from model properties to content file metadata. This is an alternative to the setEmbedMapping(Map) method. Any mappings already present will be cleared out. The property mapping is of the form: 
       # Namespaces prefixes
 namespace.prefix.cm=http://www.alfresco.org/model/content/1.0
 namespace.prefix.my=http://www....com/alfresco/1.0

 # Mapping
 cm\:author=editor
 cm\:title=title
 cm\:summary=user1
 cm\:description=description,user2
      The embed mapping can therefore be from a model property onto several content file metadata properties.
      Parameters:
      embedMappingProperties - the properties that map model properties to content file metadata properties

    • getMapping

      protected final Map<String,Set<QName>> getMapping()
      Helper method for derived classes to obtain the mappings that will be applied to raw values. This should be called after initialization in order to guarantee the complete map is given.

      Normally, the list of properties that can be extracted from a document is fixed and well-known - in that case, just extract everything. But Some implementations may have an extra, indeterminate set of values available for extraction. If the extraction of these runtime parameters is expensive, then the keys provided by the return value can be used to extract values from the documents. The metadata extraction becomes fully configuration-driven, i.e. declaring further mappings will result in more values being extracted from the documents.

      Most extractors will not be using this method.

    • getEmbedMapping

      protected final Map<QName,Set<String>> getEmbedMapping()
      Helper method for derived classes to obtain the embed mappings. This should be called after initialization in order to guarantee the complete map is given.

      Normally, the list of properties that can be embedded in a document is fixed and well-known.. But some implementations may have an extra, indeterminate set of values available for embedding. If the embedding of these runtime parameters is expensive, then the keys provided by the return value can be used to embed values in the documents. The metadata embedding becomes fully configuration-driven, i.e. declaring further mappings will result in more values being embedded in the documents.

    • readMappingProperties

      protected Map<String,Set<QName>> readMappingProperties(String propertiesUrl)
      A utility method to read mapping properties from a resource file and convert to the map form.
      Parameters:
      propertiesUrl - A standard Properties file URL location
      See Also:

    • readGlobalExtractMappingProperties

      protected Map<String,Set<QName>> readGlobalExtractMappingProperties()
      A utility method to convert global properties to the Map form for the given propertyComponent.

      Mappings can be specified using the same method defined for normal mapping properties files but with a prefix of metadata.extracter, the extracter bean name, and the extract component. For example: metadata.extracter.TikaAuto.extract.namespace.prefix.my=http://DummyMappingMetadataExtracter metadata.extracter.TikaAuto.extract.namespace.prefix.cm=http://www.alfresco.org/model/content/1.0 metadata.extracter.TikaAuto.extract.dc\:description=cm:description, my:customDescription

    • readMappingProperties

      protected Map<String,Set<QName>> readMappingProperties(Properties mappingProperties)
      A utility method to convert mapping properties to the Map form.
      See Also:

    • readEmbedMappingProperties

      protected Map<QName,Set<String>> readEmbedMappingProperties(String propertiesUrl)
      A utility method to read embed mapping properties from a resource file and convert to the map form.
      Parameters:
      propertiesUrl - A standard Properties file URL location
      See Also:

    • readGlobalEmbedMappingProperties

      protected Map<QName,Set<String>> readGlobalEmbedMappingProperties()
      A utility method to convert global mapping properties to the Map form.

      Different from readGlobalExtractMappingProperties in that keys are the Alfresco QNames and values are file metadata properties.

      Mappings can be specified using the same method defined for normal embed mapping properties files but with a prefix of metadata.extracter, the extracter bean name, and the embed component. For example: metadata.extracter.TikaAuto.embed.namespace.prefix.cm=http://www.alfresco.org/model/content/1.0 metadata.extracter.TikaAuto.embed.cm\:description=description

      See Also:

    • readEmbedMappingProperties

      protected Map<QName,Set<String>> readEmbedMappingProperties(Properties mappingProperties)
      A utility method to convert mapping properties to the Map form.

      Different from readMappingProperties in that keys are the Alfresco QNames and values are file metadata properties.

      See Also:

    • register

      public final void register()
      Registers this instance of the extracter with the registry. This will call the init() method and then register if the registry is available.
      See Also:

    • init

      protected void init()
      Provides a hook point for implementations to perform initialization. The base implementation must be invoked or the extracter will fail during extraction. The default mappings will be requested during initialization.

    • checkIsSupported

      protected void checkIsSupported(ContentReader reader)
      Checks if the mimetype is supported.
      Parameters:
      reader - the reader to check
      Throws:
      org.alfresco.error.AlfrescoRuntimeException - if the mimetype is not supported

    • checkIsEmbedSupported

      protected void checkIsEmbedSupported(ContentWriter writer)
      Checks if embedding for the mimetype is supported.
      Parameters:
      writer - the writer to check
      Throws:
      org.alfresco.error.AlfrescoRuntimeException - if embedding for the mimetype is not supported

    • extract

      public final Map<QName,Serializable> extract(ContentReader reader, Map<QName,Serializable> destination)
      Extracts the metadata values from the content provided by the reader and source mimetype to the supplied map. The internal mapping and overwrite policy between document metadata and system metadata will be used.

      The extraction viability can be determined by an up front call to MetadataExtracter.isSupported(String).

      The source mimetype must be available on the ContentAccessor.getMimetype() method of the reader.

      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      reader - the source of the content
      destination - the map of properties to populate (essentially a return value)
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.
      See Also:

    • extract

      public final Map<QName,Serializable> extract(ContentReader reader, MetadataExtracter.OverwritePolicy overwritePolicy, Map<QName,Serializable> destination)
      Extracts the metadata values from the content provided by the reader and source mimetype to the supplied map.

      The extraction viability can be determined by an up front call to MetadataExtracter.isSupported(String).

      The source mimetype must be available on the ContentAccessor.getMimetype() method of the reader.

      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      reader - the source of the content
      overwritePolicy - the policy stipulating how the system properties must be overwritten if present
      destination - the map of properties to populate (essentially a return value)
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.
      See Also:

    • extract

      public Map<QName,Serializable> extract(ContentReader reader, MetadataExtracter.OverwritePolicy overwritePolicy, Map<QName,Serializable> destination, Map<String,Set<QName>> mapping)
      Extracts the metadata from the content provided by the reader and source mimetype to the supplied map. The mapping from document metadata to system metadata is explicitly provided. The overwrite policy is also explictly set.

      The extraction viability can be determined by an up front call to MetadataExtracter.isSupported(String).

      The source mimetype must be available on the ContentAccessor.getMimetype() method of the reader.

      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      reader - the source of the content
      overwritePolicy - the policy stipulating how the system properties must be overwritten if present
      destination - the map of properties to populate (essentially a return value)
      mapping - a mapping of document-specific properties to system properties.
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.
      See Also:

    • extract

      public Map<QName,Serializable> extract(NodeRef nodeRef, ContentReader reader, Map<QName,Serializable> destination)
      Identical to MetadataExtracter.extract(ContentReader, Map) but with the addition of the NodeRef being acted on. By default, the method without the NodeRef is called.
      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      nodeRef - the node being acted on.
      reader - the source of the content
      destination - the map of properties to populate (essentially a return value)
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.

    • extract

      public Map<QName,Serializable> extract(NodeRef nodeRef, ContentReader reader, MetadataExtracter.OverwritePolicy overwritePolicy, Map<QName,Serializable> destination)
      Identical to MetadataExtracter.extract(ContentReader, OverwritePolicy,Map) but with the addition of the NodeRef being acted on. By default, the method without the NodeRef is called.
      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      nodeRef - the node being acted on.
      reader - the source of the content
      destination - the map of properties to populate (essentially a return value)
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.

    • extract

      public Map<QName,Serializable> extract(NodeRef nodeRef, ContentReader reader, MetadataExtracter.OverwritePolicy overwritePolicy, Map<QName,Serializable> destination, Map<String,Set<QName>> mapping)
      Identical to MetadataExtracter.extract(ContentReader, OverwritePolicy, Map, Map) but with the addition of the NodeRef being acted on. By default, the method without the NodeRef is called.
      Specified by:
      extract in interface MetadataExtracter
      Parameters:
      nodeRef - the node being acted on.
      reader - the source of the content
      overwritePolicy - the policy stipulating how the system properties must be overwritten if present
      destination - the map of properties to populate (essentially a return value)
      mapping - a mapping of document-specific properties to system properties.
      Returns:
      Returns a map of all properties on the destination map that were added or modified. If the return map is empty, then no properties were modified.

    • embed

      public final void embed(Map<QName,Serializable> properties, ContentReader reader, ContentWriter writer)
      Embeds the given properties into the file specified by the given content writer. *

      The embedding viability can be determined by an up front call to MetadataEmbedder.isEmbeddingSupported(String).

      The source mimetype must be available on the ContentAccessor.getMimetype() method of the writer.

      Specified by:
      embed in interface MetadataEmbedder
      Parameters:
      properties - the model properties to embed
      reader - the reader for the original source content file
      writer - the writer for the content after metadata has been embedded

    • embed

      public void embed(NodeRef nodeRef, Map<QName,Serializable> properties, ContentReader reader, ContentWriter writer)
      Identical to MetadataEmbedder.embed(Map, ContentReader, ContentWriter) but with the addition of the NodeRef being acted on. By default, the method without the NodeRef is called.
      Specified by:
      embed in interface MetadataEmbedder
      Parameters:
      nodeRef - the node being acted on.
      properties - the model properties to embed
      reader - the reader for the original source content file
      writer - the writer for the content after metadata has been embedded

    • mapSystemToRaw

      protected Map<String,Serializable> mapSystemToRaw(Map<QName,Serializable> systemMetadata)
      Parameters:
      systemMetadata - Metadata keyed by system properties
      Returns:
      Returns the metadata keyed by the content file metadata properties

    • filterSystemProperties

      protected void filterSystemProperties(Map<QName,Serializable> systemProperties, Map<QName,Serializable> targetProperties)
      Filters the system properties that are going to be applied. Gives the metadata extracter an opportunity to remove properties that may not be appropriate in a given context.
      Parameters:
      systemProperties - map of system properties to be applied
      targetProperties - map of target properties, may be used to provide to the context requried

    • convertSystemPropertyValues

      protected Map<QName,Serializable> convertSystemPropertyValues(Map<QName,Serializable> systemProperties)
      Converts all values according to their dictionary-defined type. This uses the failOnTypeConversion flag to determine how failures are handled i.e. if values fail to convert, the process may discard the property.
      Parameters:
      systemProperties - the values keyed to system property names
      Returns:
      Returns a modified map of properties that have been converted.

    • makeDate

      protected Date makeDate(String dateStr)
      Convert a date String to a Date object

    • putRawValue

      protected boolean putRawValue(String key, Serializable value, Map<String,Serializable> destination)
      Adds a value to the map, conserving null values. Values are converted to null if:
      • it is an empty string value after trimming
      • it is an empty collection
      • it is an empty array
      String values are trimmed before being put into the map. Otherwise, it is up to the extracter to ensure that the value is a Serializable. It is not appropriate to implicitly convert values in order to make them Serializable - the best conversion method will depend on the value's specific meaning.
      Parameters:
      key - the destination key
      value - the serializable value
      destination - the map to put values into
      Returns:
      Returns true if set, otherwise false

    • newRawMap

      protected final Map<String,Serializable> newRawMap()
      Helper method to fetch a clean map into which raw values can be dumped.
      Returns:
      Returns an empty map

    • getDefaultMapping

      protected Map<String,Set<QName>> getDefaultMapping()
      This method provides a best guess of where to store the values extracted from the documents. The list of properties mapped by default need not include all properties extracted from the document; just the obvious set of mappings need be supplied. Implementations must either provide the default mapping properties in the expected location or override the method to provide the default mapping.

      The default implementation looks for the default mapping file in the location given by the class name and .properties. If the extracter's class is x.y.z.MyExtracter then the default properties will be picked up at classpath:/alfresco/metadata/MyExtracter.properties. The previous location of classpath:/x/y/z/MyExtracter.properties is still supported but may be removed in a future release. Inner classes are supported, but the '$' in the class name is replaced with '-', so default properties for x.y.z.MyStuff$MyExtracter will be located using classpath:/alfresco/metadata/MyStuff-MyExtracter.properties.

      The default mapping implementation should include thorough Javadocs so that the system administrators can accurately determine how to best enhance or override the default mapping.

      If the default mapping is declared in a properties file other than the one named after the class, then the readMappingProperties(String) method can be used to quickly generate the return value: 

       
      {
          return readMappingProperties(DEFAULT_MAPPING);
      }
      The map can also be created in code either statically or during the call.
      Returns:
      Returns the default, static mapping. It may not be null.
      See Also:

    • getDefaultEmbedMapping

      protected Map<QName,Set<String>> getDefaultEmbedMapping()
      This method provides a best guess of what model properties should be embedded in content. The list of properties mapped by default need not include all properties to be embedded in the document; just the obvious set of mappings need be supplied. Implementations must either provide the default mapping properties in the expected location or override the method to provide the default mapping.

      The default implementation looks for the default mapping file in the location given by the class name and .embed.properties. If the extracter's class is x.y.z.MyExtracter then the default properties will be picked up at classpath:/x/y/z/MyExtracter.embed.properties. Inner classes are supported, but the '$' in the class name is replaced with '-', so default properties for x.y.z.MyStuff$MyExtracter will be located using x.y.z.MyStuff-MyExtracter.embed.properties.

      The default mapping implementation should include thorough Javadocs so that the system administrators can accurately determine how to best enhance or override the default mapping.

      If the default mapping is declared in a properties file other than the one named after the class, then the readEmbedMappingProperties(String) method can be used to quickly generate the return value: 

       
      protected Map<<String, Set> getDefaultMapping()
      {
          return readEmbedMappingProperties(DEFAULT_MAPPING);
      }
      The map can also be created in code either statically or during the call.

      If no embed mapping properties file is found a reverse of the extract mapping in getDefaultMapping() will be assumed with the first QName in each value used as the key for this mapping and a last win approach for duplicates.

      Returns:
      Returns the default, static embed mapping. It may not be null.
      See Also:

    • getLimits

      protected MetadataExtracterLimits getLimits(String mimetype)
      Gets the metadata extracter limits for the given mimetype.

      A specific match for the given mimetype is tried first and if none is found a wildcard of "*" is tried, if still not found defaults value will be used

      Parameters:
      mimetype - String
      Returns:
      the found limits or default values

    • extractRawInThread

      protected Map<String,Serializable> extractRawInThread(NodeRef nodeRef, ContentReader reader, MetadataExtracterLimits limits, MetadataExtracter.OverwritePolicy policy) throws Throwable
      Throws:
      Throwable

    • extractRawInThread

      protected Map<String,Serializable> extractRawInThread(NodeRef nodeRef, ContentReader reader, MetadataExtracterLimits limits) throws Throwable
      Throws:
      Throwable

    • extractRawThreadFinished

      protected void extractRawThreadFinished()

    • extractRaw

      protected abstract Map<String,Serializable> extractRaw(ContentReader reader) throws Throwable
      Override to provide the raw extracted metadata values. An extracter should extract as many of the available properties as is realistically possible. Even if the default mapping doesn't handle all properties, it is possible for each instance of the extracter to be configured differently and more or less of the properties may be used in different installations.

      Raw values must not be trimmed or removed for any reason. Null values and empty strings are

      • Null: Removed
      • Empty String: Passed to the OverwritePolicy
      • Non Serializable: Converted to String or fails if that is not possible

      Properties extracted and their meanings and types should be thoroughly described in the class-level javadocs of the extracter implementation, for example: 

       editor: - the document editor        -->  cm:author
 title:  - the document title         -->  cm:title
 user1:  - the document summary
 user2:  - the document description   -->  cm:description
 user3:  -
 user4:  -
      Parameters:
      reader - the document to extract the values from. This stream provided by the reader must be closed if accessed directly.
      Returns:
      Returns a map of document property values keyed by property name.
      Throws:
      Throwable - All exception conditions can be handled.
      See Also:

    • embedInternal

      protected void embedInternal(NodeRef nodeRef, Map<String,Serializable> metadata, ContentReader reader, ContentWriter writer) throws Throwable
      Throws:
      Throwable

    • embedInternal

      protected void embedInternal(Map<String,Serializable> metadata, ContentReader reader, ContentWriter writer) throws Throwable
      Override to embed metadata values. An extracter should embed as many of the available properties as is realistically possible. Even if the default mapping doesn't handle all properties, it is possible for each instance of the extracter to be configured differently and more or less of the properties may be used in different installations.
      Parameters:
      metadata - the metadata keys and values to embed in the content file
      reader - the reader for the original document. This stream provided by the reader must be closed if accessed directly.
      writer - the writer for the document to embed the values in. This stream provided by the writer must be closed if accessed directly.
      Throws:
      Throwable - All exception conditions can be handled.
      See Also: