Package com.icl.saxon.sort
Class BinaryTree
- java.lang.Object
-
- com.icl.saxon.sort.BinaryTree
-
public class BinaryTree extends java.lang.Object
A Binary Tree used for sorting. Similar to the java.util.Dictionary interface except (a) that the keys must be Strings rather than general Objects (b) the results are returned as a Vector, not an Enumeration.The methods getKeys() and getValues() return values in ascending order of key. The keys are compared using a default Collator which sorts in alphabetical order with intelligent handling of case and accents.
Note that duplicate keys are not allowed: a new entry silently overwrites any previous entry with the same key. If you want to use dulicate keys, append a unique value (for example, a random number) to each one.
- Version:
- 9 July 1999: now returns a Vector rather than an Enumeration
- Author:
- Michael H. Kay
-
-
Constructor Summary
Constructors Constructor Description BinaryTree()
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.Object
get(java.lang.Object key)
get(String) returns the value corresponding to a given key, if anyjava.util.Vector
getKeys()
getKeys() returns the keys in the tree in sorted order.java.util.Vector
getValues()
getValues() returns the values in the tree in sorted order.boolean
isEmpty()
isEmpty() Tests if this binary tree contains no keys.static void
main(java.lang.String[] args)
java.lang.Object
put(java.lang.Object key, java.lang.Object value)
put(Object, Object) puts a new entry in the tree, overwriting any previous entry with the same key.java.lang.Object
remove(java.lang.Object key)
remove(Object) removes the key (and its corresponding value) from this Binary Tree.void
setAscending(boolean ascending)
Set order.void
setComparer(Comparer c)
Set the Comparer to be used for the keys in this tree.void
setDuplicatesAllowed(boolean allow)
Define whether duplicate keys are allowed or not.int
size()
size()
-
-
-
Method Detail
-
setAscending
public void setAscending(boolean ascending)
Set order. This must be called before any nodes are added to the tree. Default is ascending order- Parameters:
ascending
- true indicates ascending order; false indicates descending
-
setDuplicatesAllowed
public void setDuplicatesAllowed(boolean allow)
Define whether duplicate keys are allowed or not. If duplicates are allowed, objects with the same key value will be sequenced in order of arrival. If duplicates are not allowed, a new value will overwrite an existing value with the same key.
-
setComparer
public void setComparer(Comparer c)
Set the Comparer to be used for the keys in this tree. At the time this is called, the tree must be empty
-
getValues
public java.util.Vector getValues()
getValues() returns the values in the tree in sorted order.- Returns:
- an Vector containing the values in this BinaryTree (in key order).
-
getKeys
public java.util.Vector getKeys()
getKeys() returns the keys in the tree in sorted order.- Returns:
- an Vector containing the keys in this BinaryTree (in key order).
-
get
public java.lang.Object get(java.lang.Object key)
get(String) returns the value corresponding to a given key, if any- Parameters:
key
- The key value being sought- Returns:
- the value to which the key is mapped in this binary tree, or null if there is no entry with this key
-
isEmpty
public boolean isEmpty()
isEmpty() Tests if this binary tree contains no keys.- Returns:
- true if there are no entries in the tree
-
put
public java.lang.Object put(java.lang.Object key, java.lang.Object value)
put(Object, Object) puts a new entry in the tree, overwriting any previous entry with the same key.- Parameters:
key
- The value of the key. Note this must be a String, and must not be null.value
- The value to be associated with this key. Must not be null.- Returns:
- the value previously associated with this key, if there was one. Otherwise null.
-
remove
public java.lang.Object remove(java.lang.Object key)
remove(Object) removes the key (and its corresponding value) from this Binary Tree. If duplicates are allowed it removes at most one entry with this key- Parameters:
key
- identifies the entry to be removed- Returns:
- the value that was associated with this key, if there was one. Otherwise null.
-
size
public int size()
size()- Returns:
- the number of entries in this binary tree.
-
main
public static void main(java.lang.String[] args) throws java.lang.Exception
- Throws:
java.lang.Exception
-
-