com.sleepycat.persist.impl
Class EnumFormat

java.lang.Object
  extended by com.sleepycat.persist.impl.Format
      extended by com.sleepycat.persist.impl.EnumFormat
All Implemented Interfaces:
RawType, java.io.Serializable

public class EnumFormat
extends Format

Format for all enum types. In this class we resort to using reflection to allocate arrays of enums. If there is a need for it, reflection could be avoided in the future by generating code as new array formats are encountered.

Author:
Mark Hayes
See Also:
Serialized Form

Field Summary
 
Fields inherited from class com.sleepycat.persist.impl.Format
ID_BIGDEC, ID_BIGINT, ID_BOOL, ID_BOOL_W, ID_BYTE, ID_BYTE_W, ID_CHAR, ID_CHAR_W, ID_DATE, ID_DOUBLE, ID_DOUBLE_W, ID_FLOAT, ID_FLOAT_W, ID_INT, ID_INT_W, ID_LONG, ID_LONG_W, ID_NULL, ID_OBJECT, ID_PREDEFINED, ID_SHORT, ID_SHORT_W, ID_SIMPLE_MAX, ID_SIMPLE_MIN, ID_STRING
 
Constructor Summary
EnumFormat(java.lang.Class type)
           
 
Method Summary
(package private)  void collectRelatedFormats(Catalog catalog, java.util.Map<java.lang.String,Format> newFormats)
          Calls catalog.createFormat for formats that this format depends on, or that should also be persistent.
 boolean equals(java.lang.Object other)
          Used to compare the current version and an old version, to determine whether class evolution is needed.
 java.util.List<java.lang.String> getEnumConstants()
          Returns an unmodifiable list of the names of the enum instances, or null if this is not an enum type.
(package private)  void initialize(Catalog catalog)
          Initializes an uninitialized format, initializing its related formats (superclass formats and array component formats) first.
 boolean isEnum()
          Returns whether this is an enum type.
(package private)  java.lang.Object newArray(int len)
          Creates an array of the format's class of the given length, as if Array.newInstance(getType(), len) were called.
(package private)  java.lang.Object newInstance(EntityInput input, boolean rawAccess)
          Creates a new instance of the target class using its default constructor.
(package private)  void readObject(java.lang.Object o, EntityInput input, boolean rawAccess)
          Called after newInstance() to read the rest of the data bytes and fill in the object contents.
(package private)  void skipContents(EntityInput input)
          Skips over the object's contents, as if readObject() were called, but without returning an object.
(package private)  void writeObject(java.lang.Object o, EntityOutput output, boolean rawAccess)
          Writes a given instance of the target class to the output data bytes.
 
Methods inherited from class com.sleepycat.persist.impl.Format
copySecKey, copySecMultiKey, evolveTo, getClassMetadata, getClassName, getComponentType, getDimensions, getEntityFormat, getEntityMetadata, getFields, getId, getProxiedFormat, getSuperFormat, getSuperType, getType, getVersion, getWrapperFormat, initializeIfNeeded, isArray, isAssignableTo, isCurrentVersion, isEntity, isModelClass, isPredefined, isPriKeyNullOrZero, isPrimitive, isSimple, nullifySecKey, readPriKey, setId, setProxiedFormat, setSuperFormat, skipToSecKey, writePriKey
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EnumFormat

EnumFormat(java.lang.Class type)
Method Detail

isEnum

public boolean isEnum()
Description copied from interface: RawType
Returns whether this is an enum type.

If true is returned, a value of this type is a RawObject and the enum constant String is available via RawObject.getEnum().

If false is returned, then this is a complex type, an array type (see RawType.isArray()), or a simple type (see RawType.isSimple()).

Specified by:
isEnum in interface RawType
Overrides:
isEnum in class Format

getEnumConstants

public java.util.List<java.lang.String> getEnumConstants()
Description copied from interface: RawType
Returns an unmodifiable list of the names of the enum instances, or null if this is not an enum type.

Specified by:
getEnumConstants in interface RawType
Overrides:
getEnumConstants in class Format

collectRelatedFormats

void collectRelatedFormats(Catalog catalog,
                           java.util.Map<java.lang.String,Format> newFormats)
Description copied from class: Format
Calls catalog.createFormat for formats that this format depends on, or that should also be persistent.

Specified by:
collectRelatedFormats in class Format

initialize

void initialize(Catalog catalog)
Description copied from class: Format
Initializes an uninitialized format, initializing its related formats (superclass formats and array component formats) first.

Specified by:
initialize in class Format

newArray

java.lang.Object newArray(int len)
Description copied from class: Format
Creates an array of the format's class of the given length, as if Array.newInstance(getType(), len) were called. Formats implement this method for specific classes, or call the accessor, to avoid the reflection overhead of Array.newInstance.

Specified by:
newArray in class Format

newInstance

java.lang.Object newInstance(EntityInput input,
                             boolean rawAccess)
Description copied from class: Format
Creates a new instance of the target class using its default constructor. Normally this creates an empty object, and readObject() is called next to fill in the contents. This is done in two steps to allow the instance to be registered by EntityInput before reading the contents. This allows the fields in an object or a nested object to refer to the parent object in a graph. Alternatively, this method may read all or the first portion of the data, rather than that being done by readObject(). This is required for simple types and enums, where the object cannot be created without reading the data. In these cases, there is no possibility that the parent object will be referenced by the child object in the graph. It should not be done in other cases, or the graph references may not be maintained faithfully.

Specified by:
newInstance in class Format

writeObject

void writeObject(java.lang.Object o,
                 EntityOutput output,
                 boolean rawAccess)
Description copied from class: Format
Writes a given instance of the target class to the output data bytes. This is the complement of the newInstance()/readObject() pair.

Specified by:
writeObject in class Format

readObject

void readObject(java.lang.Object o,
                EntityInput input,
                boolean rawAccess)
Description copied from class: Format
Called after newInstance() to read the rest of the data bytes and fill in the object contents. If the object was read completely by newInstance(), this method does nothing.

Specified by:
readObject in class Format

skipContents

void skipContents(EntityInput input)
Description copied from class: Format
Skips over the object's contents, as if readObject() were called, but without returning an object. Used for extracting secondary key bytes without having to instantiate the object. For reference types, the format ID is read just before calling this method, so this method is responsible for skipping everything following the format ID.

Specified by:
skipContents in class Format

equals

public boolean equals(java.lang.Object other)
Description copied from class: Format
Used to compare the current version and an old version, to determine whether class evolution is needed. Subclasses should always override this method and also call super.equals() as part of their comparison.

Overrides:
equals in class Format


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