Package com.tangosol.util.extractor

Class UniversalExtractor<T,​E>

    • Field Detail

      • BEAN_ACCESSOR_PREFIXES

        public static final String[] BEAN_ACCESSOR_PREFIXES
        JavaBean accessor prefixes.

      • m_sName

        protected String m_sName
        A method or property name.

      • m_aoParam

        protected Object[] m_aoParam
        The parameter array. Must be null or zero length for a property based extractor.

      • m_sNameCanon

        protected transient String m_sNameCanon
        Canonical name for this extractor.

        Note: subclasses are responsible for initialization and POF and/or Lite serialization of this field.

    • Constructor Detail

      • UniversalExtractor

        public UniversalExtractor()
        Default constructor (necessary for the ExternalizableLite interface).

      • UniversalExtractor

        public UniversalExtractor​(String sName)
        Construct a UniversalExtractor based on syntax of sName.

        If sName does not end in METHOD_SUFFIX, "()", this extractor is a property extractor. If sName is prefixed with one of the BEAN_ACCESSOR_PREFIXES and ends in the METHOD_SUFFIX, this extractor is a property extractor. Otherwise, if the sName just ends in {#link #METHOD_SUFFIX}, this extractor is considered a method extractor.

        Parameters:
        sName - a method or property name

      • UniversalExtractor

        public UniversalExtractor​(String sName,
                          Object[] aoParam)
        Construct a UniversalExtractor based on a name and optional parameters.

        If sName does not end in METHOD_SUFFIX, "()", and has no aoParams,this extractor is a property extractor. If sName is prefixed with one of the BEAN_ACCESSOR_PREFIXES, ends in METHOD_SUFFIX and has no aoParams,this extractor is a property extractor. Otherwise, if the sNamejust ends in {#link #METHOD_SUFFIX}, this extractor is considered a method extractor.

        Parameters:
        sName - a method or property name
        aoParam - the array of arguments to be used in the method invocation; may be null
        Throws:
        IllegalArgumentException - when sName does not end in METHOD_SUFFIX and aoParam array length is one or more.

      • UniversalExtractor

        public UniversalExtractor​(String sName,
                          Object[] aoParam,
                          int nTarget)
        Construct a UniversalExtractor based on a name, optional parameters and the entry extraction target.

        If sName does not end in METHOD_SUFFIX, "()", this extractor is a property extractor. If sName is prefixed with one of the BEAN_ACCESSOR_PREFIXES and ends in METHOD_SUFFIX, this extractor is a property extractor. If the sName just ends in METHOD_SUFFIX, this extractor is considered a method extractor.

        Parameters:
        sName - a method or property name
        aoParam - the array of arguments to be used in the method invocation; may be null
        nTarget - one of the AbstractExtractor.VALUE or AbstractExtractor.KEY values
        Throws:
        IllegalArgumentException - when sName does not end in METHOD_SUFFIX and aoParam array length is one or more.

    • Method Detail

      • extract

        public E extract​(T oTarget)
        Extract from target using reflection or map access.

        If name is a property, reflection accessor method lookup on T fails and oTarget is an instance Map, use canonical name to get value from target.

        Specified by:
        extract in interface ValueExtractor<T,​E>
        Overrides:
        extract in class AbstractExtractor<T,​E>
        Parameters:
        oTarget - the target
        Returns:
        value extracted from target

      • getCanonicalName

        public String getCanonicalName()
        Description copied from interface: ValueExtractor
        Return the canonical name for this extractor.

        A canonical name uniquely identifies what is to be extracted, but not how it is to be extracted. Thus two different extractor implementations with the same non-null canonical name are considered to be equal, and should reflect this in their implementations of hashCode and equals.

        Canonical names for properties are designated by their property name in camel case, for instance a Java Bean with method getFooBar would have a property named fooBar, and would have fooBar as its canonical name.

        Canonical names for zero-arg method invocations are the method name followed by ().

        Dots in a canonical name delimit one or more property/method accesses represented by a chaining ValueExtractor such as ChainedExtractor or PofExtractor(Class, PofNavigator, String).

        There is currently no canonical name format for methods which take parameters and as such they must return a canonical name of null.

        Specified by:
        getCanonicalName in interface CanonicallyNamed
        Specified by:
        getCanonicalName in interface ValueExtractor<T,​E>
        Overrides:
        getCanonicalName in class AbstractExtractor<T,​E>
        Returns:
        the extractor's canonical name, or null

      • equals

        public boolean equals​(Object o)
        Compare the UniversalExtractor with another object to determine equality.

        AbstractExtractor.equals(Object) contract takes precedence when applicable, falling back to implementation specific equals.

        Two UniversalExtractor objects, re1 and re2 are considered equal if re1.extract(o) equals re2.extract(o) for all values of o.

        Specified by:
        equals in interface Comparator<T>
        Specified by:
        equals in interface ValueExtractor<T,​E>
        Overrides:
        equals in class AbstractExtractor<T,​E>
        Parameters:
        o - the reference object with which to compare
        Returns:
        true iff this UniversalExtractor and the passed object are equivalent

      • hashCode

        public int hashCode()
        HashCode value is hashCode of non-null canonical name; otherwise, it is the hashCode of sName passed to {#link UniversalExtractor(String)}.
        Specified by:
        hashCode in interface ValueExtractor<T,​E>
        Overrides:
        hashCode in class AbstractExtractor<T,​E>
        Returns:
        an integer hash value for this UniversalExtractor object

      • toString

        public String toString()
        Provide a human-readable description of this UniversalExtractor object.
        Overrides:
        toString in class Object
        Returns:
        a human-readable description of this UniversalExtractor object

      • init

        protected void init()
        Called in constructor and deserializers.

      • getMethodName

        public String getMethodName()
        Return the method name that this extractor is configured to invoke. If a reflection-based method extractor, isMethodExtractor(), return the method name to be invoked. If a property extractor, return the likely JavaBean accessor method name.
        Returns:
        method name

      • getPropertyName

        public String getPropertyName()
        Return the property name of this extractor.
        Returns:
        property name of this extractor; otherwise, return null.

      • isPropertyExtractor

        public boolean isPropertyExtractor()
        Return true if this is a Property extractor.
        Returns:
        true if this a property extractor.

      • isMethodExtractor

        public boolean isMethodExtractor()
        Return true if this a method extractor.
        Returns:
        true if this is a method extractor.

      • getParameters

        public Object[] getParameters()
        Return the array of arguments used to invoke the method.
        Returns:
        the array of arguments used to invoke the method

      • extractComplex

        protected E extractComplex​(T oTarget)
                    throws InvocationTargetException,
                           IllegalAccessException
        Extract from target using reflection or map access. If name is a property, reflection accessor method lookup on T fails and T is an instance Map, use canonical name to get value from target. If successful, cache the reflection computation.
        Parameters:
        oTarget - the target
        Returns:
        value extracted from target
        Throws:
        InvocationTargetException - if reflection method lookup fails
        IllegalAccessException - if reflection method lookup fails

      • createExtractor

        public static <T,​E> ValueExtractor<T,​E> createExtractor​(String sNames)
        Return a ValueExtractor representing dot separated list of property and/or method names.
        Type Parameters:
        T - the type of the value to extract from
        E - the type of value that will be extracted
        Parameters:
        sNames - dot-delimited property and/or methods name(s)
        Returns:
        UniversalExtractor if only one name in parameter; otherwise, return a ChainedExtractor with a UniversalExtractor for each name.

      • readExternal

        public void readExternal​(DataInput in)
                  throws IOException
        Restore the contents of this object by loading the object's state from the passed DataInput object.
        Specified by:
        readExternal in interface ExternalizableLite
        Parameters:
        in - the DataInput stream to read data from in order to restore the state of this object
        Throws:
        IOException - if an I/O exception occurs
        NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

      • writeExternal

        public void writeExternal​(DataOutput out)
                   throws IOException
        Save the contents of this object by storing the object's state into the passed DataOutput object.
        Specified by:
        writeExternal in interface ExternalizableLite
        Parameters:
        out - the DataOutput stream to write the state of this object to
        Throws:
        IOException - if an I/O exception occurs

      • readExternal

        public void readExternal​(PofReader in)
                  throws IOException
        Restore the contents of a user type instance by reading its state using the specified PofReader object.
        Specified by:
        readExternal in interface PortableObject
        Parameters:
        in - the PofReader from which to read the object's state
        Throws:
        IOException - if an I/O error occurs

      • writeExternal

        public void writeExternal​(PofWriter out)
                   throws IOException
        Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
        Specified by:
        writeExternal in interface PortableObject
        Parameters:
        out - the PofWriter to which to write the object's state
        Throws:
        IOException - if an I/O error occurs