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java.lang.Objectcom.sleepycat.persist.impl.Format
com.sleepycat.persist.impl.CompositeKeyFormat
public class CompositeKeyFormat
Format for a composite key class. This class is similar to ComplexFormat in that a composite key class and other complex classes have fields, and the Accessor interface is used to access those fields. Composite key classes are different in the following ways: - The superclass must be Object. No inheritance is allowed. - All instance fields must be annotated with @KeyField, which determines their order in the data bytes. - Although fields may be reference types (primitive wrappers or other simple reference types), they are stored as if they were primitives. No object format ID is stored, and the class of the object must be the declared classs of the field; i.e., no polymorphism is allowed for key fields. In other words, a composite key is stored as an ordinary tuple as defined in the com.sleepycat.bind.tuple package. This keeps the key small and gives it a well defined sort order. - If the key class implements Comparable, it is called by the Database btree comparator. It must therefore be available during JE recovery, before the store and catalog have been opened. To support this, this format can be constructed during recovery. A SimpleCatalog singleton instance is used to provide a catalog of simple types that is used by the composite key format. - When interacting with the Accessor, the composite key format treats the Accessor's non-key fields as its key fields. The Accessor's key fields are secondary keys, while the composite format's key fields are the component parts of a single key.
Method Summary | |
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java.util.Map<java.lang.String,RawField> |
getFields()
Returns a map of field name to raw field for each non-static non-transient field declared in this class, or null if this is not a complex type (in other words, this is a simple type or an array type). |
java.lang.Object |
newInstance(EntityInput input,
boolean rawAccess)
Creates a new instance of the target class using its default constructor. |
java.lang.Object |
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. |
Methods inherited from class com.sleepycat.persist.impl.Format |
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getClassName, getComponentType, getDimensions, getEnumConstants, getPreviousVersion, getSuperType, getVersion, initializeReader, isArray, isEnum, isPrimitive, isSimple, readPriKey, toString |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Method Detail |
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public java.util.Map<java.lang.String,RawField> getFields()
RawType
getFields
in interface RawType
getFields
in class Format
public java.lang.Object newInstance(EntityInput input, boolean rawAccess)
Format
newInstance
in class Format
public java.lang.Object readObject(java.lang.Object o, EntityInput input, boolean rawAccess)
Format
readObject
in class Format
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