com.coyotegulch.jisp
public abstract class KeyObject extends Object implements Externalizable
KeyObject defines an characteristics of an object to be used as a key * in an ObjectIndex. Since Java lacks true generic types, it is up to * the programmer to ensure that all KeyObjects have the same concrete type * for a given ObjectIndex. Each ObjectIndex supports a single * concrete KeyObject type. * * Concrete KeyObject classes must always produce a
See Also: ObjectIndex
| Field Summary | |
|---|---|
| static int | KEY_EQUAL
Returned by compareTo when the invoking key is greater than the parameter key.
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| static int | KEY_ERROR
Returned by compareTo when the invoking key has a different type from the parameter key.
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| static int | KEY_LESS
Returned by compareTo when the invoking key is less than the parameter key.
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| static int | KEY_MORE
Returned by compareTo when the invoking key equals the parameter key.
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| Method Summary | |
|---|---|
| abstract int | compareTo(KeyObject key)
Compares the invoking object to key, returning one of the KEY_*
constants based on the relationship of the two keys.
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| abstract KeyObject | makeNullKey()
Returns a "null" (i.e., blank) key, to be used as a space-holder in certain kinds of
ObjectIndexes.
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| String | toString()
Returns the String representation of a KeyObject.
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compareTo when the invoking key is greater than the parameter key.
compareTo when the invoking key has a different type from the parameter key.
compareTo when the invoking key is less than the parameter key.
compareTo when the invoking key equals the parameter key.
key, returning one of the KEY_*
constants based on the relationship of the two keys.
Parameters: key The key value to be compared against the invoking key. * @return One of the KEY_* constants based on the relationship of the two keys.
ObjectIndexes.
For example, a BTreeIndex maintains a set of index pages that must contain
a set number of fixed-length keys. When creating a BTreeIndex, you must provide
a "null" key, using the makeNullKey method.
Returns: A "null" (i.e., blank) key constant.
See Also: BTreeIndex
String representation of a KeyObject.
Returns: The String representation of a KeyObject.