Class ElementUnionLabel

java.lang.Object
org.simpleframework.xml.core.TemplateLabel
org.simpleframework.xml.core.ElementUnionLabel
All Implemented Interfaces:
Label

class ElementUnionLabel extends TemplateLabel
The ElementUnionLabel is an adapter for an internal label. Each annotation within the union can be acquired by type so that deserialization can dynamically switch the converter used. Each union label can be used in place of any other, this means that regardless of which union is matched it can be used.

Each instance of this Label is given the union and the primary label it represents. This allows the label extract each other label within the union group. The Converter created by this can therefore acquire any label instance required.

See Also:
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private Contact
    This is the contact that this label is associated with.
    This is used to extract the individual unions in the group.
    private Label
    This is the label that this acts as an adapter to.
    private Expression
    This is the expression that is associated with this label.
    private ElementUnion
    This is the union associated with this label instance.
  • Constructor Summary

    Constructors
    Constructor
    Description
    ElementUnionLabel(Contact contact, ElementUnion union, Element element, Format format)
    Constructor for the ElementUnionLabel object.
  • Method Summary

    Modifier and Type
    Method
    Description
    This acquires the annotation associated with this label.
    This is used to acquire the contact object for this label.
    This method returns a Converter which can be used to convert an XML node into an object value and vice versa.
    This is used to acquire the Decorator for this.
    This returns the dependent type for the annotation.
    getEmpty(Context context)
    This is used to provide a configured empty value used when the annotated value is null.
    This is used to either provide the entry value provided within the annotation or compute a entry value.
    This method is used to return an XPath expression that is used to represent the position of this label.
    This is used to acquire the Label that the type provided is represented by.
    This is used to acquire the name of the element or attribute that is used by the class schema.
    This returns a Collection of element names.
    This is used to acquire the name of the element or attribute as taken from the annotation.
    This is used to acquire the path of the element or attribute that is used by the class schema.
    This returns a Collection of element paths.
    This acts as a convenience method used to determine the type of the field this represents.
    getType(Class type)
    This is used to acquire the Type that the type provided is represented by.
    boolean
    This is used to determine if the label is a collection.
    boolean
    This is used to determine whether the annotation requires it and its children to be written as a CDATA block.
    boolean
    This is used to determine whether the label represents an inline XML entity.
    boolean
    Determines whether the XML attribute or element is required.
    boolean
    This is used to determine if this label is a union.
    This is used to describe the annotation and method or field that this label represents.

    Methods inherited from class org.simpleframework.xml.core.TemplateLabel

    getKey, isAttribute, isText, isTextList

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
  • Field Details

    • extractor

      private GroupExtractor extractor
      This is used to extract the individual unions in the group.
    • union

      private ElementUnion union
      This is the union associated with this label instance.
    • path

      private Expression path
      This is the expression that is associated with this label.
    • contact

      private Contact contact
      This is the contact that this label is associated with.
    • label

      private Label label
      This is the label that this acts as an adapter to.
  • Constructor Details

    • ElementUnionLabel

      public ElementUnionLabel(Contact contact, ElementUnion union, Element element, Format format) throws Exception
      Constructor for the ElementUnionLabel object. This is given the union this represents as well as the individual element it will act as an adapter for. This allows the union label to acquire any other label within the group.
      Parameters:
      contact - this is the contact associated with the union
      union - this is the union annotation this represents
      element - this is the individual annotation used
      format - this is the format used to style the union
      Throws:
      Exception
  • Method Details

    • isUnion

      public boolean isUnion()
      This is used to determine if this label is a union. If this is true then this label represents a number of labels and is simply a wrapper for these labels.
      Specified by:
      isUnion in interface Label
      Overrides:
      isUnion in class TemplateLabel
      Returns:
      this returns true if the label represents a union
    • getContact

      public Contact getContact()
      This is used to acquire the contact object for this label. The contact retrieved can be used to set any object or primitive that has been deserialized, and can also be used to acquire values to be serialized in the case of object persistence. All contacts that are retrieved from this method will be accessible.
      Returns:
      returns the field that this label is representing
    • getAnnotation

      public Annotation getAnnotation()
      This acquires the annotation associated with this label. This is typically the annotation acquired from the field or method. However, in the case of unions this will return the actual annotation within the union group that this represents.
      Returns:
      this returns the annotation that this represents
    • getLabel

      public Label getLabel(Class type) throws Exception
      This is used to acquire the Label that the type provided is represented by. Typically this will return the same instance. However, in the case of unions this will look for an individual label to match the type provided.
      Specified by:
      getLabel in interface Label
      Overrides:
      getLabel in class TemplateLabel
      Parameters:
      type - this is the type to acquire the label for
      Returns:
      this returns the label represented by this type
      Throws:
      Exception
    • getType

      public Type getType(Class type) throws Exception
      This is used to acquire the Type that the type provided is represented by. Typically this will return the field or method represented by the label. However, in the case of unions this will provide an override type.
      Specified by:
      getType in interface Label
      Overrides:
      getType in class TemplateLabel
      Parameters:
      type - this is the class to acquire the type for
      Returns:
      this returns the type represented by this class
      Throws:
      Exception
    • getConverter

      public Converter getConverter(Context context) throws Exception
      This method returns a Converter which can be used to convert an XML node into an object value and vice versa. The converter requires only the context object in order to perform serialization or deserialization of the provided XML node.
      Parameters:
      context - this is the context object for the serialization
      Returns:
      this returns an object that is used for conversion
      Throws:
      Exception
    • getNames

      public String[] getNames() throws Exception
      This returns a Collection of element names. This will typically contain both the name and path of the label. However, if this is a union it can contain many names and paths. This method should never return null.
      Specified by:
      getNames in interface Label
      Overrides:
      getNames in class TemplateLabel
      Returns:
      this returns the names of each of the elements
      Throws:
      Exception
    • getPaths

      public String[] getPaths() throws Exception
      This returns a Collection of element paths. This will typically contain only the path of the label, which is composed using the Path annotation and the name of the label. However, if this is a union it can contain many paths. This method should never return null.
      Specified by:
      getPaths in interface Label
      Overrides:
      getPaths in class TemplateLabel
      Returns:
      this returns the names of each of the elements
      Throws:
      Exception
    • getEmpty

      public Object getEmpty(Context context) throws Exception
      This is used to provide a configured empty value used when the annotated value is null. This ensures that XML can be created with required details regardless of whether values are null or not. It also provides a means for sensible default values.
      Parameters:
      context - this is the context object for the serialization
      Returns:
      this returns the string to use for default values
      Throws:
      Exception
    • getDecorator

      public Decorator getDecorator() throws Exception
      This is used to acquire the Decorator for this. A decorator is an object that adds various details to the node without changing the overall structure of the node. For example comments and namespaces can be added to the node with a decorator as they do not affect the deserialization.
      Returns:
      this returns the decorator associated with this
      Throws:
      Exception
    • getDependent

      public Type getDependent() throws Exception
      This returns the dependent type for the annotation. This type is the type other than the annotated field or method type that the label depends on. For the ElementList and the ElementArray this is the component type that is deserialized individually and inserted into the container.
      Specified by:
      getDependent in interface Label
      Overrides:
      getDependent in class TemplateLabel
      Returns:
      this is the type that the annotation depends on
      Throws:
      Exception
    • getEntry

      public String getEntry() throws Exception
      This is used to either provide the entry value provided within the annotation or compute a entry value. If the entry string is not provided the the entry value is calculated as the type of primitive the object is as a simplified class name.
      Specified by:
      getEntry in interface Label
      Overrides:
      getEntry in class TemplateLabel
      Returns:
      this returns the name of the XML entry element used
      Throws:
      Exception
    • getName

      public String getName() throws Exception
      This is used to acquire the name of the element or attribute that is used by the class schema. The name is determined by checking for an override within the annotation. If it contains a name then that is used, if however the annotation does not specify a name the the field or method name is used instead.
      Returns:
      returns the name that is used for the XML property
      Throws:
      Exception
    • getPath

      public String getPath() throws Exception
      This is used to acquire the path of the element or attribute that is used by the class schema. The path is determined by acquiring the XPath expression and appending the name of the label to form a fully qualified path.
      Returns:
      returns the path that is used for the XML property
      Throws:
      Exception
    • getExpression

      public Expression getExpression() throws Exception
      This method is used to return an XPath expression that is used to represent the position of this label. If there is no XPath expression associated with this then an empty path is returned. This will never return a null expression.
      Returns:
      the XPath expression identifying the location
      Throws:
      Exception
    • getOverride

      public String getOverride()
      This is used to acquire the name of the element or attribute as taken from the annotation. If the element or attribute explicitly specifies a name then that name is used for the XML element or attribute used. If however no overriding name is provided then the method or field is used for the name.
      Returns:
      returns the name of the annotation for the contact
    • getType

      public Class getType()
      This acts as a convenience method used to determine the type of the field this represents. This is used when an object is written to XML. It determines whether a class attribute is required within the serialized XML element, that is, if the class returned by this is different from the actual value of the object to be serialized then that type needs to be remembered.
      Returns:
      this returns the type of the field class
    • isCollection

      public boolean isCollection()
      This is used to determine if the label is a collection. If the label represents a collection then any original assignment to the field or method can be written to without the need to create a new collection. This allows obscure collections to be used and also allows initial entries to be maintained.
      Specified by:
      isCollection in interface Label
      Overrides:
      isCollection in class TemplateLabel
      Returns:
      true if the label represents a collection value
    • isData

      public boolean isData()
      This is used to determine whether the annotation requires it and its children to be written as a CDATA block. This is done when a primitive or other such element requires a text value and that value needs to be encapsulated within a CDATA block.
      Returns:
      this returns true if the element requires CDATA
    • isInline

      public boolean isInline()
      This is used to determine whether the label represents an inline XML entity. The ElementList annotation and the Text annotation represent inline items. This means that they contain no containing element and so can not specify overrides or special attributes.
      Specified by:
      isInline in interface Label
      Overrides:
      isInline in class TemplateLabel
      Returns:
      this returns true if the annotation is inline
    • isRequired

      public boolean isRequired()
      Determines whether the XML attribute or element is required. This ensures that if an XML element is missing from a document that deserialization can continue. Also, in the process of serialization, if a value is null it does not need to be written to the resulting XML document.
      Returns:
      true if the label represents a some required data
    • toString

      public String toString()
      This is used to describe the annotation and method or field that this label represents. This is used to provide error messages that can be used to debug issues that occur when processing a method. This will provide enough information such that the problem can be isolated correctly.
      Specified by:
      toString in interface Label
      Overrides:
      toString in class Object
      Returns:
      this returns a string representation of the label