@GwtCompatible(serializable=true) @Beta public class TreeBasedTable<R,C extends Object,V>
Table
whose row keys and column keys are ordered by their natural ordering or by supplied comparators. When constructing a
TreeBasedTable
, you may provide comparators for the row keys and the column keys, or you may use natural ordering for both.
The rowKeySet()
method returns a SortedSet
and the rowMap()
method returns a SortedMap
, instead of the Set
and Map
specified by the Table
interface.
The views returned by column(C)
, columnKeySet()
, and columnMap()
have iterators that don't support remove()
. Otherwise, all optional operations are supported. Null row keys, columns keys, and values are not supported.
Lookups by row key are often faster than lookups by column key, because the data is stored in a Map<R, Map<C, V>>
. A method call like column(columnKey).get(rowKey)
still runs quickly, since the row key is provided. However, column(columnKey).size()
takes longer, since an iteration across all row keys occurs.
Because a TreeBasedTable
has unique sorted values for a given row, both row(rowKey)
and rowMap().get(rowKey)
are SortedMap
instances, instead of the Map
specified in the Table
interface.
Note that this implementation is not synchronized. If multiple threads access this table concurrently and one of the threads modifies the table, it must be synchronized externally.
See the Guava User Guide article on Table
.
Table.Cell <R,C,V>
Modifier and Type | Method and Description |
---|---|
Set |
cellSet()
Returns a set of all row key / column key / value triplets.
|
void |
clear()
Removes all mappings from the table.
|
Map |
column(C columnKey)
Returns a view of all mappings that have the given column key.
|
Comparator |
columnComparator()
Returns the comparator that orders the columns.
|
Set |
columnKeySet()
Returns a set of column keys that have one or more values in the table.
|
Map |
columnMap()
Returns a view that associates each column key with the corresponding map from row keys to values.
|
boolean |
contains(Object
Returns
true if the table contains a mapping with the specified row and column keys.
|
boolean |
containsColumn(Object
Returns
true if the table contains a mapping with the specified column.
|
boolean |
containsRow(Object
Returns
true if the table contains a mapping with the specified row key.
|
boolean |
containsValue(Object
Returns
true if the table contains a mapping with the specified value.
|
static <R extends Comparable |
create()
Creates an empty
TreeBasedTable that uses the natural orderings of both row and column keys.
|
static <R |
create(Comparator
Creates an empty
TreeBasedTable that is ordered by the specified comparators.
|
static <R |
create(TreeBasedTable
Creates a
TreeBasedTable with the same mappings and sort order as the specified
TreeBasedTable .
|
boolean |
equals(Object
Compares the specified object with this table for equality.
|
V |
get(Object
Returns the value corresponding to the given row and column keys, or
null if no such mapping exists.
|
int |
hashCode()
Returns the hash code for this table.
|
boolean |
isEmpty()
Returns
true if the table contains no mappings.
|
V |
put(R rowKey, C columnKey, V value)
Associates the specified value with the specified keys.
|
void |
putAll(Table
Copies all mappings from the specified table to this table.
|
V |
remove(Object
Removes the mapping, if any, associated with the given keys.
|
SortedMap |
row(R rowKey)
Returns a view of all mappings that have the given row key.
|
Comparator |
rowComparator()
Returns the comparator that orders the rows.
|
SortedSet |
rowKeySet()
Returns a set of row keys that have one or more values in the table.
|
SortedMap |
rowMap()
Returns a view that associates each row key with the corresponding map from column keys to values.
|
int |
size()
Returns the number of row key / column key / value mappings in the table.
|
String |
toString()
Returns the string representation
rowMap().toString() .
|
Collection |
values()
Returns a collection of all values, which may contain duplicates.
|
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
cellSet, clear, column, columnKeySet, columnMap, contains, containsColumn, containsRow, containsValue, equals, get, hashCode, isEmpty, put, putAll, remove, size, values
public static <R extends Comparable,C extends Comparable ,V> TreeBasedTable <R ,C ,V> create()
TreeBasedTable
that uses the natural orderings of both row and column keys.
The method signature specifies R extends Comparable
with a raw Comparable
, instead of R extends Comparable<? super R>
, and the same for C
. That's necessary to support classes defined without generics.
public static <R,C ,V> TreeBasedTable <R ,C ,V> create(Comparator <? super R> rowComparator, Comparator <? super C> columnComparator)
TreeBasedTable
that is ordered by the specified comparators.
rowComparator
- the comparator that orders the row keys
columnComparator
- the comparator that orders the column keys
public static <R,C ,V> TreeBasedTable <R ,C ,V> create(TreeBasedTable <R ,C ,? extends V> table)
TreeBasedTable
with the same mappings and sort order as the specified
TreeBasedTable
.
public Comparator<? super R> rowComparator()
Ordering.natural()
is returned.
public Comparator<? super C> columnComparator()
Ordering.natural()
is returned.
public SortedMap<C ,V> row(R rowKey)
Changes to the returned map will update the underlying table, and vice versa.
Because a TreeBasedTable
has unique sorted values for a given row, this method returns a SortedMap
, instead of the Map
specified in the Table
interface.
public SortedMap<R ,Map <C ,V>> rowMap()
put()
or
putAll()
, or
setValue()
on its entries.
In contrast, the maps returned by rowMap().get()
have the same behavior as those returned by Table
. Those maps may support setValue()
, put()
, and putAll()
.
This method returns a SortedMap
, instead of the Map
specified in the Table
interface.
public boolean contains(ObjectrowKey, Object columnKey)
Table
true
if the table contains a mapping with the specified row and column keys.
public boolean containsColumn(ObjectcolumnKey)
Table
true
if the table contains a mapping with the specified column.
containsColumn
in interface
Table<R,C,V>
columnKey
- key of column to search for
public boolean containsRow(ObjectrowKey)
Table
true
if the table contains a mapping with the specified row key.
containsRow
in interface
Table<R,C,V>
rowKey
- key of row to search for
public boolean containsValue(Objectvalue)
Table
true
if the table contains a mapping with the specified value.
containsValue
in interface
Table<R,C,V>
value
- value to search for
public V get(ObjectrowKey, Object columnKey)
Table
null
if no such mapping exists.
public boolean isEmpty()
Table
true
if the table contains no mappings.
public int size()
Table
public void clear()
Table
public V put(R rowKey, C columnKey, V value)
Table
put
in interface
Table<R,C,V>
rowKey
- row key that the value should be associated with
columnKey
- column key that the value should be associated with
value
- value to be associated with the specified keys
null
if no mapping existed for the keys
public V remove(ObjectrowKey, Object columnKey)
Table
public Set<Table .Cell <R ,C ,V>> cellSet()
add
or
addAll
methods.
The set's iterator traverses the mappings for the first row, the mappings for the second row, and so on.
Each cell is an immutable snapshot of a row key / column key / value mapping, taken at the time the cell is returned by a method call to the set or its iterator.
public Map<R ,V> column(C columnKey)
Changes to the returned map will update the underlying table, and vice versa.
The returned map's views have iterators that don't support remove()
.
public Set<C> columnKeySet()
The returned set has an iterator that does not support remove()
.
The set's iterator traverses the columns of the first row, the columns of the second row, etc., skipping any columns that have appeared previously.
columnKeySet
in interface
Table<R,C,V>
public Collection<V> values()
The collection's iterator traverses the values for the first row, the values for the second row, and so on.
public Map<C ,Map <R ,V>> columnMap()
Table
put()
or
putAll()
, or
setValue()
on its entries.
In contrast, the maps returned by columnMap().get()
have the same behavior as those returned by Table
. Those maps may support setValue()
, put()
, and putAll()
.
public void putAll(Table<? extends R ,? extends C ,? extends V> table)
Table
Table.put(R, C, V)
with each row key / column key / value mapping in
table
.
public boolean equals(Objectobj)
Table
Table.cellSet()
, are equal.
public int hashCode()
Table
Table.cellSet()
.
public StringtoString()
rowMap().toString()
.