Package com.tangosol.io.pof

Class ConfigurablePofContext

  • All Implemented Interfaces:
    ClassLoaderAware, PofContext, Serializer, XmlConfigurable
    Direct Known Subclasses:
    SafeConfigurablePofContext
    @Named("pof")
public class ConfigurablePofContext
extends Object
implements PofContext, ClassLoaderAware, XmlConfigurable
    This class implements the PofContext interface using information provided in a configuration file (or in a passed XML configuration) as well as classes annotated with PortableType.

    For each user type supported by this POF context, it must be provided with:

    • A valid user type ID that is unique within this POF context;
    • A Java class name that identifies a Java class or interface that all values of the user type are type-assignable to (and that no values of other user types are type-assignable to); in other words, all values of the user type (and no values of other user types) are instances of the specified class, instances of a sub-class of the specified class, or (if it is an interface) instances of a class that implements the specified interface;
    • A Java class name that identifies a non-abstract implementation of the PofSerializer interface.

    The format of the configuration XML is as follows: 

    
 <pof-config>
   <user-type-list>
     ..
     <user-type>
       <type-id>53</type-id>
       <class-name>com.mycompany.data.Trade</class-name>
       <serializer>
         <class-name>com.tangosol.io.pof.PortableObjectSerializer</class-name>
         <init-params>
           <init-param>
             <param-type>int</param-type>
             <param-value>{type-id}</param-value>
           </init-param>
         </init-params>
       </serializer>
     </user-type>

     <user-type>
       <type-id>54</type-id>
       <class-name>com.mycompany.data.Position</class-name>
     </user-type>

     ..
     <include>file:/my-pof-config.xml</include>

     ..
   </user-type-list>

   <allow-interfaces>false</allow-interfaces>
   <allow-subclasses>false</allow-subclasses>
 </pof-config>
    For each user type, a user-type element must exist inside the user-type-list element. The user-type-list element contains up to three elements, in the following order:
    • The user-type element should contain a type-id element whose value specifies the unique integer type ID; if none of the user-type elements contains a type-id element, then the type IDs for the user types will be based on the order in which they appear in the configuration, with the first user type being assigned the type ID 0, the second user type being assigned the type ID 1, and so on. (It is strongly recommended that user types IDs always be specified, in order to support schema versioning and evolution.)
    • The class-name element is required, and specifies the fully qualified name of the Java class or interface that all values of the user type are type-assignable to.
    • The serializer element is used to specify an implementation of PofSerializer to use to serialize and deserialize user type values to and from a POF stream. Within the serializer element, the class-name element is required, and zero or more constructor parameters can be defined within an init-params block. If no serializer is specified, either implement the PortableObject interface or have a Portable annotation. If the former, a PortableObjectSerializer will be used. If the later, a PofAnnotationSerializer will be used.

    The optional include element allows user-type elements defined in another configuration XML to be added to the user type list. The value of this element is a locator string (either a valid path or URL) that specifies the location of the target PofContext configuration file. The user-type elements of the target file are imported verbatum; therefore, if the included elements contain explicit type identifiers, each identifier must be unique with respect to the the user type identifiers (either explicit or generated) defined within the including file. If the included user types do not contain explicit type identifiers, then the type identifiers will be based on the order in which the user types appear in the composite configuration file. Multiple include elements may be used within a single user-type-list element.

    The ConfigurablePofContext is truly ClassLoader-aware. It is conceivable that the ConfigurablePofContext is loaded by the system ClassLoader (or some other relatively global ClassLoader), while the objects deserialized by the PofContext are loaded by an application-specific ClassLoader, such as is typical within an application server. The ConfigurablePofContext is designed to load the configuration, the POF-able object classes and the PofSerializer classes from within a specified ClassLoader context, and to pass the ClassLoader information on to the PofSerializer instances, just in case they are not loaded from within the application's ClassLoader context. In other words, the ConfigurablePofContext, its configuration, the PofSerializer classes and the POF-able classes can all be loaded by the same ClassLoader, or they can all be loaded by different ClassLoaders, so long as the configuration, the POF-able classes and the PofSerializer classes can be loaded by either the specified ClassLoader or by the ClassLoader that loaded the ConfigurablePofContext itself.

    In order to be used by the ConfigurablePofContext, a PofSerializer implementation must provide a public constructor that accepts the parameters detailed by the init-params element. The parameter values, as specified by the param-value element, can specify one of the following substitutable values:

    • {type-id} - replaced with the Type ID of the User Type;
    • {class-name} - replaced with the name of the class for the User Type;
    • {class} - replaced with the Class for the User Type;
    • {class-loader} - replaced with the ConfigurablePofContext's ContextClassLoader.
    If the init-params element is not present, then the ConfigurablePofContext attempts to construct the PofSerializer by searching for one of the following constructors in the same order as they appear here:
    • (int nTypeId, Class clz, ClassLoader loader)
    • (int nTypeId, Class clz)
    • (int nTypeId)
    • ()

    Once constructed, if the PofSerializer implements the XmlConfigurable interface, the setConfig method is invoked, and it is passed the parameter XML information, transposed as described by transformInitParams, and as described in the coherence-pof-config.xsd file.

    Finally, if the PofSerializer implements the ClassLoaderAware interface and a ClassLoader has been specified, then the setContextClassLoader method is invoked with the reference to the specified ClassLoader.

    Conceptually, the identity of a ConfigurablePofContext is a combination of a configuration locator and a ClassLoader. The ClassLoader is used to resolve and load the configuration details whose location is specified by the configuration locator, and to load all of the classes specified by the configuration. To achieve acceptable performance, and to limit the redundant use of resources, the ConfigurablePofContext maintains a WeakHashMap keyed by ClassLoader, whose corresponding values are each a SafeHashMap keyed by configuration locator, whose corresponding values contain the data necessary to efficiently perform the operations prescribed by the PofContext interface.

    Note: The configuration for the default constructor can be specified using the tangosol.pof.config system property.

    Since:
    Coherence 3.2
    Author:
    jh/cp 2006.07.24

    • Field Detail

      • PROPERTY_CONFIG

        public static final String PROPERTY_CONFIG
        The name of the system property ("tangosol.pof.config") that can be used to override the location of the default POF configuration file.

        The value of this property must be the name of a resource that contains an XML document with the structure defined in /coherence-pof-config.xsd (deployed in coherence.jar).

        The default value for the "coherence.pof.config" system property is "coherence-pof-config.xml".

        See Also:
        Constant Field Values

      • DEFAULT_RESOURCE

        public static final String DEFAULT_RESOURCE
        The name of the application resource that contains the default set of wire-format-to-object bindings.

        The default value for the resource name is "pof-config.xml". The default can be overriden by specifying a value for the tangosol.pof.config system property.

      • ROOT_LAMBDA_CLASS

        protected static final Class ROOT_LAMBDA_CLASS
        Marker serving as the implicit root class for all lambdas.

      • DEFAULT_INDEX_FILE_NAME

        protected static final String DEFAULT_INDEX_FILE_NAME
        Default Jandex index file.
        See Also:
        Constant Field Values

    • Constructor Detail

      • ConfigurablePofContext

        public ConfigurablePofContext()
        Default constructor.

        Create a default ConfigurablePofContext that will load configuration information from the locator specified in DEFAULT_RESOURCE.

      • ConfigurablePofContext

        public ConfigurablePofContext​(String sLocator)
        Create a ConfigurablePofContext that will load configuration information from the specified locator.
        Parameters:
        sLocator - the locator that specifies the location of the PofContext configuration file; the locator is either a valid path or a URL

      • ConfigurablePofContext

        public ConfigurablePofContext​(XmlElement xml)
        Create a ConfigurablePofContext that will use the passed configuration information.
        Parameters:
        xml - an XmlElement containing information in the format of a configuration file used by ConfigurablePofContext

      • ConfigurablePofContext

        public ConfigurablePofContext​(ConfigurablePofContext that)
        Copy constructor for a ConfigurablePofContext.
        Parameters:
        that - the ConfigurablePofContext to (shallow) copy from

    • Method Detail

      • getConfig

        public XmlElement getConfig()
        Determine the current configuration of the object.
        Specified by:
        getConfig in interface XmlConfigurable
        Returns:
        the XML configuration or null

      • setConfig

        public void setConfig​(XmlElement xml)
        Specify the configuration for the object.

        Note that the configuration cannot be set after the ConfigurablePofContext is fully initialized.

        Specified by:
        setConfig in interface XmlConfigurable
        Parameters:
        xml - the XML configuration for the object
        Throws:
        IllegalStateException - if the ConfigurablePofContext is already fully initialized

      • getContextClassLoader

        public ClassLoader getContextClassLoader()
        Retrieve the context ClassLoader for this object. The context ClassLoader is provided by the creator of the object for use by the object when loading classes and resources.
        Specified by:
        getContextClassLoader in interface ClassLoaderAware
        Returns:
        the context ClassLoader for this object
        See Also:
        Thread.getContextClassLoader()

      • setContextClassLoader

        public void setContextClassLoader​(ClassLoader loader)
        Specify the context ClassLoader for this object. The context ClassLoader can be set when the object is created, and allows the creator to provide the appropriate class loader to be used by the object when when loading classes and resources.

        Note that the ConfigurablePofContext will fully initialize when it is provided a ClassLoader.

        Specified by:
        setContextClassLoader in interface ClassLoaderAware
        Parameters:
        loader - the context ClassLoader for this object
        Throws:
        IllegalStateException - if the ConfigurablePofContext is already fully initialized

      • serialize

        public void serialize​(WriteBuffer.BufferOutput out,
                      Object o)
               throws IOException
        Serialize an object to a WriteBuffer by writing its state using the specified BufferOutput object.

        Note: Starting with Coherence 12.2.1 classes that need to designate an alternative object to be used by the Serializer when writing the object to the buffer should implement the SerializationSupport.writeReplace() method.

        Specified by:
        serialize in interface Serializer
        Parameters:
        out - the BufferOutput with which to write the object's state
        o - the object to serialize
        Throws:
        IOException - if an I/O error occurs

      • deserialize

        public Object deserialize​(ReadBuffer.BufferInput in)
                   throws IOException
        Deserialize an object from a ReadBuffer by reading its state using the specified BufferInput object.

        Note: Starting with Coherence 12.2.1 classes that need to designate an alternative object to be returned by the Serializer after an object is deserialized from the buffer should implement the SerializationSupport.readResolve() method.

        Specified by:
        deserialize in interface Serializer
        Parameters:
        in - the BufferInput with which to read the object's state
        Returns:
        the deserialized user type instance
        Throws:
        IOException - if an I/O error occurs

      • getName

        public String getName()
        Description copied from interface: Serializer
        Return the name of this serializer.
        Specified by:
        getName in interface Serializer
        Returns:
        the name of this serializer

      • getPofSerializer

        public PofSerializer getPofSerializer​(int nTypeId)
        Return a PofSerializer that can be used to serialize and deserialize an object of the specified user type to and from a POF stream.
        Specified by:
        getPofSerializer in interface PofContext
        Parameters:
        nTypeId - the type identifier of the user type that can be serialized and deserialized using the returned PofSerializer; must be non-negative
        Returns:
        a PofSerializer for the specified user type

      • getUserTypeIdentifier

        public int getUserTypeIdentifier​(Object o)
        Determine the user type identifier associated with the given object.
        Specified by:
        getUserTypeIdentifier in interface PofContext
        Parameters:
        o - an instance of a user type; must not be null
        Returns:
        the type identifier of the user type associated with the given object

      • getUserTypeIdentifier

        public int getUserTypeIdentifier​(Class clz)
        Determine the user type identifier associated with the given class.
        Specified by:
        getUserTypeIdentifier in interface PofContext
        Parameters:
        clz - a user type class; must not be null
        Returns:
        the type identifier of the user type associated with the given class

      • getUserTypeIdentifier

        public int getUserTypeIdentifier​(String sClass)
        Determine the user type identifier associated with the given class name.
        Specified by:
        getUserTypeIdentifier in interface PofContext
        Parameters:
        sClass - the name of a user type class; must not be null
        Returns:
        the type identifier of the user type associated with the given class name

      • getClassName

        public String getClassName​(int nTypeId)
        Determine the name of the class associated with the given user type identifier.
        Specified by:
        getClassName in interface PofContext
        Parameters:
        nTypeId - the user type identifier; must be non-negative
        Returns:
        the name of the class associated with the specified user type identifier

      • getClass

        public Class getClass​(int nTypeId)
        Determine the class associated with the given user type identifier.
        Specified by:
        getClass in interface PofContext
        Parameters:
        nTypeId - the user type identifier; must be non-negative
        Returns:
        the class associated with the specified user type identifier

      • isUserType

        public boolean isUserType​(Object o)
        Determine if the given object is of a user type known to this PofContext.
        Specified by:
        isUserType in interface PofContext
        Parameters:
        o - the object to test; must not be null
        Returns:
        true iff the specified object is of a valid user type

      • isUserType

        public boolean isUserType​(Class clz)
        Determine if the given class is a user type known to this PofContext.
        Specified by:
        isUserType in interface PofContext
        Parameters:
        clz - the class to test; must not be null
        Returns:
        true iff the specified class is a valid user type

      • isUserType

        public boolean isUserType​(String sClass)
        Determine if the class with the given name is a user type known to this PofContext.
        Specified by:
        isUserType in interface PofContext
        Parameters:
        sClass - the name of the class to test; must not be null
        Returns:
        true iff the class with the specified name is a valid user type

      • isPreferJavaTime

        public boolean isPreferJavaTime()
        Return true if PofReader.readObject(int) method should return the appropriate Java 8 date/time type, or false if a legacy date/time types should be returned in order to preserve backwards compatibility.
        Specified by:
        isPreferJavaTime in interface PofContext
        Returns:
        true if Java 8 date/time types should be preferred over legacy types

      • getUserTypeIdentifierInternal

        protected int getUserTypeIdentifierInternal​(Class clz)
        Determine the user type identifier associated with the given class.
        Parameters:
        clz - a user type class; must not be null
        Returns:
        the type identifier of the user type associated with the given class or -1 if the user type is unknown to this PofContext

      • getInheritedUserTypeIdentifier

        protected int getInheritedUserTypeIdentifier​(Class clz)
        Helper method for determining the user type identifier associated with a given class that does not have a direct configured association.
        Parameters:
        clz - a user type class; must not be null
        Returns:
        the type identifier of the user type associated with the given class or -1 if the user type and its superclass(es) and implemented interface(s) are unknown to this PofContext

      • getUserTypeIdentifierInternal

        protected int getUserTypeIdentifierInternal​(String sClass)
        Determine the user type identifier associated with the given class name.
        Parameters:
        sClass - the name of a user type class; must not be null
        Returns:
        the type identifier of the user type associated with the given class name or -1 if the user type is unknown to this PofContext

      • isInitialized

        protected boolean isInitialized()
        Determine if the ConfigurablePofContext has completed its initialization.
        Returns:
        true iff the initialization is complete

      • getConfigLocation

        protected String getConfigLocation()
        Obtain the location of the configuration that the ConfigurablePofContext used to configure itself.
        Returns:
        the location information for the configuration for the ConfigurablePofContext, or null if not yet initialized and no location was specified

      • getPofConfig

        protected ConfigurablePofContext.PofConfig getPofConfig()
        Obtain the PofConfig that represents the initialized state of the ConfigurablePofContext.
        Returns:
        the PofConfig for the ConfigurablePofContext, or null if not yet initialized

      • isInterfaceAllowed

        protected boolean isInterfaceAllowed()
        Determine if the ConfigurablePofContext supports the configuration of user types by specifying an interface (instead of a class) for the Java type.
        Returns:
        true iff an interface name is acceptable in the configuration as the class of a user type

      • isSubclassAllowed

        protected boolean isSubclassAllowed()
        Determine if the ConfigurablePofContext supports the serialization of an object that is an instance of a sub-class of a configured type, but not actually an instance of a class of a configured type.
        Returns:
        true iff serialization of sub-classes is explicitly enabled

      • isLambdaAllowed

        protected boolean isLambdaAllowed()
        Determine if implicit root lambda class processing is allowed.
        Returns:
        true iff implicit root lambda class processing is allowed.

      • isReferenceEnabled

        public boolean isReferenceEnabled()
        Determine if Identity/Reference type support is enabled for this ConfigurablePofContext.
        Returns:
        true if Identity/Reference type support is enabled

      • setReferenceEnabled

        public void setReferenceEnabled​(boolean fReferenceEnabled)
        Set the referenceEnabled flag.
        Parameters:
        fReferenceEnabled - the referenceEnabled flag to set

      • setPreferJavaTime

        public void setPreferJavaTime​(boolean fPreferJavaTime)
        Set the flag specifying if Java 8 date/time types (java.time.*) should be preferred over legacy types.
        Parameters:
        fPreferJavaTime - whether Java 8 data/time types

      • setIndexFileName

        public void setIndexFileName​(String sIndexFile)
        Set the Jandex index file name to use to discover portable types.
        Parameters:
        sIndexFile - Jandex index file name to use to discover portable types

      • getIndexFileName

        public String getIndexFileName()
        Return the Jandex index file name to use to discover portable types.
        Returns:
        the Jandex index file name to use to discover portable types

      • toString

        public String toString()
        Return a description of this ConfigurablePofContext.
        Overrides:
        toString in class Object
        Returns:
        a String representation of the ConfigurablePofContext object

      • checkNotInitialized

        protected void checkNotInitialized()
        Verify that the ConfigurablePofContext has not already been initialized.
        Throws:
        IllegalStateException - if the ConfigurablePofContext is already fully initialized

      • ensureInitialized

        protected void ensureInitialized()
        Fully initialize the ConfigurablePofContext if it has not already been initialized.

      • initialize

        protected void initialize()
        Bind the ConfigurablePofContext to a ClassLoader, resolving all class names, etc.

      • createPofConfig

        protected ConfigurablePofContext.PofConfig createPofConfig()
        Create a PofConfig object based on a configuration that was either provided as XML, or can be loaded from the specified (or default) URI using the provided ClassLoader.
        Returns:
        a PofConfig for this ConfigurablePofContext

      • instantiateSerializer

        protected PofSerializer instantiateSerializer​(XmlElement xmlSer,
                                              int nTypeId,
                                              Class clz)
        Create a PofSerializer from the provided XML serializer element.
        Parameters:
        xmlSer - xml defining the serializer to create
        nTypeId - the user type id this class is registered with
        clz - the class of the user type
        Returns:
        a PofSerializer implementation capable of (de)serializing clz

      • instantiateSerializer

        protected PofSerializer<?> instantiateSerializer​(Class<? extends PofSerializer> clzSer,
                                                 Integer nTypeId,
                                                 Class<?> clz)
        Instantiate specified PofSerializer.
        Parameters:
        clzSer - the class of the serializer to create
        nTypeId - the user type id this class is registered with
        clz - the class of the user type
        Returns:
        a PofSerializer implementation capable of (de)serializing clz

      • loadClass

        protected Class loadClass​(String sClass)
        Find the specified class, return a Java Class object for it.
        Parameters:
        sClass - the fully qualified class name
        Returns:
        the Class object for the specified class name, never null
        Throws:
        RuntimeException - a RuntimeException (or a subclass thereof) is thrown if the specified Class could not be loaded

      • report

        protected void report​(String sURI,
                      int nTypeId,
                      String sClass,
                      Throwable e,
                      String sText)
        Assemble and throw an informative exception based on the passed details.
        Parameters:
        sURI - the URI of the configuration
        nTypeId - the type ID (if applicable and if known)
        sClass - the user type class name (if applicable and if known)
        e - the underlying exception, if any
        sText - the detailed description of the problem
        Throws:
        IllegalStateException - always thrown

      • mergeIncludes

        public static void mergeIncludes​(String sURI,
                                 XmlElement xmlConfig,
                                 ClassLoader loader)
        Merge all included POF configuration files into the given xml configuration.
        Parameters:
        sURI - the URI of the POF configuration file
        xmlConfig - the base POF configuration
        loader - the ClassLoader used to find the included POF configuration resources

      • appendDefaultSerializerToUserTypes

        protected static void appendDefaultSerializerToUserTypes​(XmlElement xmlConfig)
        Process <default-serializer> element from the specified xml configuration and append information about the serializer to each <user-type> element within <user-type-list> unless user type already has a serializer specified.

        This method could be overridden to add new custom configuration elements to pof-config.

        Parameters:
        xmlConfig - the XmlElement containing pof configuration