@GwtCompatible(serializable=true) public class TreeBasedTable<R,C,V> extends Object
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<Table.Cell<R,C,V>> |
cellSet()
Returns a set of all row key / column key / value triplets.
|
void |
clear()
Removes all mappings from the table.
|
Map<R,V> |
column(C columnKey)
Returns a view of all mappings that have the given column key.
|
Comparator<? super C> |
columnComparator()
Deprecated.
Store the
Comparator alongside the Table . Or, if you know that the
Table contains at least one value, you can retrieve the Comparator with:
((SortedMap<C, V>) table.rowMap().values().iterator().next()).comparator(); . This
method is scheduled for removal in April 2019. |
Set<C> |
columnKeySet()
Returns a set of column keys that have one or more values in the table.
|
Map<C,Map<R,V>> |
columnMap()
Returns a view that associates each column key with the corresponding map
from row keys to values.
|
boolean |
contains(Object rowKey,
Object columnKey)
Returns
true if the table contains a mapping with the specified row and column keys. |
boolean |
containsColumn(Object columnKey)
Returns
true if the table contains a mapping with the specified column. |
boolean |
containsRow(Object rowKey)
Returns
true if the table contains a mapping with the specified row key. |
boolean |
containsValue(Object value)
Returns
true if the table contains a mapping with the specified value. |
static <R extends Comparable,C extends Comparable,V> |
create()
Creates an empty
TreeBasedTable that uses the natural orderings
of both row and column keys. |
static <R,C,V> TreeBasedTable<R,C,V> |
create(Comparator<? super R> rowComparator,
Comparator<? super C> columnComparator)
Creates an empty
TreeBasedTable that is ordered by the specified
comparators. |
static <R,C,V> TreeBasedTable<R,C,V> |
create(TreeBasedTable<R,C,? extends V> table)
Creates a
TreeBasedTable with the same mappings and sort order
as the specified TreeBasedTable . |
boolean |
equals(Object obj)
Compares the specified object with this table for equality.
|
V |
get(Object rowKey,
Object columnKey)
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<? extends R,? extends C,? extends V> table)
Copies all mappings from the specified table to this table.
|
V |
remove(Object rowKey,
Object columnKey)
Removes the mapping, if any, associated with the given keys.
|
SortedMap<C,V> |
row(R rowKey)
Returns a view of all mappings that have the given row key.
|
Comparator<? super R> |
rowComparator()
Deprecated.
Use
table.rowKeySet().comparator() instead. This method is scheduled for
removal in April 2019. |
SortedSet<R> |
rowKeySet()
Returns a set of row keys that have one or more values in the table.
|
SortedMap<R,Map<C,V>> |
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<V> |
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 keyscolumnComparator
- the comparator that orders the column keyspublic 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
.@Deprecated public Comparator<? super R> rowComparator()
table.rowKeySet().comparator()
instead. This method is scheduled for
removal in April 2019.Ordering.natural()
is returned.@Deprecated public Comparator<? super C> columnComparator()
Comparator
alongside the Table
. Or, if you know that the
Table
contains at least one value, you can retrieve the Comparator
with:
((SortedMap<C, V>) table.rowMap().values().iterator().next()).comparator();
. This
method is scheduled for removal in April 2019.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.row(R)
. 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(@Nullable Object rowKey, @Nullable Object columnKey)
Table
true
if the table contains a mapping with the specified row and column keys.public boolean containsColumn(@Nullable Object columnKey)
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 forpublic boolean containsRow(@Nullable Object rowKey)
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 forpublic boolean containsValue(@Nullable Object value)
Table
true
if the table contains a mapping with the specified value.containsValue
in interface Table<R,C,V>
value
- value to search forpublic V get(@Nullable Object rowKey, @Nullable 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 withcolumnKey
- column key that the value should be associated withvalue
- value to be associated with the specified keysnull
if
no mapping existed for the keyspublic V remove(@Nullable Object rowKey, @Nullable 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.column(C)
. 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(@Nullable Object obj)
Table
Table.cellSet()
, are equal.public int hashCode()
Table
Table.cellSet()
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