public class HashBasedTable<R,C,V> extends StandardTable<R,C,V>
Table
using linked hash tables. This guarantees predictable iteration
order of the various views.
The views returned by StandardTable.column(C)
, StandardTable.columnKeySet()
, and StandardTable.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.
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
.
Modifier and Type | Class and Description |
---|---|
private static class |
HashBasedTable.Factory<C,V> |
StandardTable.Row, StandardTable.RowMap
AbstractTable.CellSet, AbstractTable.Values
Table.Cell<R,C,V>
Modifier and Type | Field and Description |
---|---|
private static long |
serialVersionUID |
backingMap, factory
Constructor and Description |
---|
HashBasedTable(java.util.Map<R,java.util.Map<C,V>> backingMap,
HashBasedTable.Factory<C,V> factory) |
Modifier and Type | Method and Description |
---|---|
boolean |
contains(java.lang.Object rowKey,
java.lang.Object columnKey)
Returns
true if the table contains a mapping with the specified row and column keys. |
boolean |
containsColumn(java.lang.Object columnKey)
Returns
true if the table contains a mapping with the specified column. |
boolean |
containsRow(java.lang.Object rowKey)
Returns
true if the table contains a mapping with the specified row key. |
boolean |
containsValue(java.lang.Object value)
Returns
true if the table contains a mapping with the specified value. |
static <R,C,V> HashBasedTable<R,C,V> |
create()
Creates an empty
HashBasedTable . |
static <R,C,V> HashBasedTable<R,C,V> |
create(int expectedRows,
int expectedCellsPerRow)
Creates an empty
HashBasedTable with the specified map sizes. |
static <R,C,V> HashBasedTable<R,C,V> |
create(Table<? extends R,? extends C,? extends V> table)
Creates a
HashBasedTable with the same mappings as the specified table. |
boolean |
equals(java.lang.Object obj)
Compares the specified object with this table for equality.
|
V |
get(java.lang.Object rowKey,
java.lang.Object columnKey)
Returns the value corresponding to the given row and column keys, or
null if no such
mapping exists. |
V |
remove(java.lang.Object rowKey,
java.lang.Object columnKey)
Removes the mapping, if any, associated with the given keys.
|
cellIterator, cellSet, cellSpliterator, clear, column, columnKeySet, columnMap, createColumnKeyIterator, createRowMap, isEmpty, put, row, rowKeySet, rowMap, size, values
createCellSet, createValues, hashCode, putAll, toString, valuesIterator, valuesSpliterator
private static final long serialVersionUID
public static <R,C,V> HashBasedTable<R,C,V> create()
HashBasedTable
.public static <R,C,V> HashBasedTable<R,C,V> create(int expectedRows, int expectedCellsPerRow)
HashBasedTable
with the specified map sizes.expectedRows
- the expected number of distinct row keysexpectedCellsPerRow
- the expected number of column key / value mappings in each rowjava.lang.IllegalArgumentException
- if expectedRows
or expectedCellsPerRow
is
negativepublic static <R,C,V> HashBasedTable<R,C,V> create(Table<? extends R,? extends C,? extends V> table)
HashBasedTable
with the same mappings as the specified table.table
- the table to copyjava.lang.NullPointerException
- if any of the row keys, column keys, or values in table
is
nullpublic boolean contains(java.lang.Object rowKey, java.lang.Object columnKey)
Table
true
if the table contains a mapping with the specified row and column keys.public boolean containsColumn(java.lang.Object columnKey)
Table
true
if the table contains a mapping with the specified column.containsColumn
in interface Table<R,C,V>
containsColumn
in class StandardTable<R,C,V>
columnKey
- key of column to search forpublic boolean containsRow(java.lang.Object rowKey)
Table
true
if the table contains a mapping with the specified row key.containsRow
in interface Table<R,C,V>
containsRow
in class StandardTable<R,C,V>
rowKey
- key of row to search forpublic boolean containsValue(java.lang.Object value)
Table
true
if the table contains a mapping with the specified value.containsValue
in interface Table<R,C,V>
containsValue
in class StandardTable<R,C,V>
value
- value to search forpublic V get(java.lang.Object rowKey, java.lang.Object columnKey)
Table
null
if no such
mapping exists.public boolean equals(java.lang.Object obj)
Table
Table.cellSet()
, are equal.