Class HashBasedTable<R,C,V>

java.lang.Object

cloud.opencode.base.collections.HashBasedTable<R,C,V>

Type Parameters:

R - row key type | 行键类型

C - column key type | 列键类型

V - value type | 值类型

All Implemented Interfaces:

Table<R,C,V>, Serializable

public class HashBasedTable<R,C,V>
extends Object
implements Table<R,C,V>, Serializable

HashBasedTable - Hash-based Table Implementation HashBasedTable - 基于哈希的表实现

A Table implementation backed by nested HashMaps. Provides O(1) average time for most operations.

由嵌套 HashMap 支持的 Table 实现。大多数操作提供 O(1) 平均时间。

Features | 主要功能:

• O(1) average time operations - O(1) 平均时间操作
• Allows null values but not null keys - 允许空值但不允许空键
• Serializable - 可序列化
• Live views - 实时视图

Usage Examples | 使用示例:

// Create empty - 创建空
HashBasedTable<String, String, Integer> table = HashBasedTable.create();

// Create with expected size - 创建指定预期大小
HashBasedTable<String, String, Integer> table = HashBasedTable.create(10, 5);

// Create from existing - 从现有创建
HashBasedTable<String, String, Integer> table = HashBasedTable.create(existingTable);

// Operations - 操作
table.put("A", "X", 1);
table.put("A", "Y", 2);
table.put("B", "X", 3);

table.get("A", "X");     // 1
table.row("A");          // {X=1, Y=2}
table.column("X");       // {A=1, B=3}

Performance | 性能特性:

• get/put/remove: O(1) average - get/put/remove: O(1) 平均
• contains: O(1) average - contains: O(1) 平均
• row: O(1) - row: O(1)
• column: O(n) first access, O(1) cached - column: O(n) 首次访问, O(1) 缓存

Security | 安全性:

• Thread-safe: No - 线程安全: 否
• Null-safe: Values yes, keys no - 空值安全: 值是，键否

Since:

JDK 25, opencode-base-collections V1.0.0

Author:

Leon Soo www.LeonSoo.com

See Also:

• OpenCode.cloud
• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface Table

Table.Cell<R,C,V>

Method Summary

Modifier and Type	Method	Description
Set<Table.Cell<R,C,V>>	cellSet()	Return a view of all cells.
void	clear()	Clear all mappings.
Map<R,V>	column(C columnKey)	Return a map view for a specific column.
Set<C>	columnKeySet()	Return a view of all column keys.
Map<C,Map<R,V>>	columnMap()	Return a map view of all columns.
boolean	contains(Object rowKey, Object columnKey)	Check if the table contains a mapping with the row and column keys.
boolean	containsColumn(Object columnKey)	Check if the table contains a mapping with the column key.
boolean	containsRow(Object rowKey)	Check if the table contains a mapping with the row key.
boolean	containsValue(Object value)	Check if the table contains a mapping with the value.
static <R,C,V> HashBasedTable<R,C,V>	create()	Create an empty HashBasedTable.
static <R,C,V> HashBasedTable<R,C,V>	create(int expectedRows, int expectedColumns)	Create an empty HashBasedTable with expected sizes.
static <R,C,V> HashBasedTable<R,C,V>	create(Table<? extends R, ? extends C, ? extends V> table)	Create a HashBasedTable from an existing table.
boolean	equals(Object o)
V	get(Object rowKey, Object columnKey)	Get the value at the specified row and column.
int	hashCode()
boolean	isEmpty()	Check if the table contains any mappings.
V	put(R rowKey, C columnKey, V value)	Put a value at the specified row and column.
void	putAll(Table<? extends R, ? extends C, ? extends V> table)	Put all values from another table.
V	remove(Object rowKey, Object columnKey)	Remove the value at the specified row and column.
Map<C,V>	row(R rowKey)	Return a map view for a specific row.
Set<R>	rowKeySet()	Return a view of all row keys.
Map<R,Map<C,V>>	rowMap()	Return a map view of all rows.
int	size()	Return the number of row-column-value mappings.
String	toString()
Collection<V>	values()	Return a view of all values.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Details

create

public static <R,C,V> HashBasedTable<R,C,V> create()

Create an empty HashBasedTable. 创建空 HashBasedTable。

Type Parameters:

R - row key type | 行键类型

C - column key type | 列键类型

V - value type | 值类型

Returns:

new HashBasedTable | 新的 HashBasedTable

create

public static <R,C,V> HashBasedTable<R,C,V> create(int expectedRows,
 int expectedColumns)

Create an empty HashBasedTable with expected sizes. 创建指定预期大小的空 HashBasedTable。

Type Parameters:

R - row key type | 行键类型

C - column key type | 列键类型

V - value type | 值类型

Parameters:

expectedRows - expected row count | 预期行数

expectedColumns - expected column count | 预期列数

Returns:

new HashBasedTable | 新的 HashBasedTable

create

public static <R,C,V> HashBasedTable<R,C,V> create(Table<? extends R, ? extends C, ? extends V> table)

Create a HashBasedTable from an existing table. 从现有表创建 HashBasedTable。

Type Parameters:

R - row key type | 行键类型

C - column key type | 列键类型

V - value type | 值类型

Parameters:

table - source table | 源表

Returns:

new HashBasedTable | 新的 HashBasedTable

isEmpty

public boolean isEmpty()

Description copied from interface: Table

Check if the table contains any mappings. 检查表是否为空。

Specified by:

isEmpty in interface Table<R,C,V>

Returns:

true if empty | 如果为空则返回 true

size

public int size()

Description copied from interface: Table

Return the number of row-column-value mappings. 返回行列值映射的数量。

Specified by:

size in interface Table<R,C,V>

Returns:

size | 大小

clear

public void clear()

Description copied from interface: Table

Clear all mappings. 清除所有映射。

Specified by:

clear in interface Table<R,C,V>

contains

public boolean contains(Object rowKey,
 Object columnKey)

Description copied from interface: Table

Check if the table contains a mapping with the row and column keys. 检查表是否包含指定行列键的映射。

Specified by:

contains in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

columnKey - the column key | 列键

Returns:

true if contains | 如果包含则返回 true

containsRow

public boolean containsRow(Object rowKey)

Description copied from interface: Table

Check if the table contains a mapping with the row key. 检查表是否包含指定行键的映射。

Specified by:

containsRow in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

Returns:

true if contains | 如果包含则返回 true

containsColumn

public boolean containsColumn(Object columnKey)

Description copied from interface: Table

Check if the table contains a mapping with the column key. 检查表是否包含指定列键的映射。

Specified by:

containsColumn in interface Table<R,C,V>

Parameters:

columnKey - the column key | 列键

Returns:

true if contains | 如果包含则返回 true

containsValue

public boolean containsValue(Object value)

Description copied from interface: Table

Check if the table contains a mapping with the value. 检查表是否包含指定值的映射。

Specified by:

containsValue in interface Table<R,C,V>

Parameters:

value - the value | 值

Returns:

true if contains | 如果包含则返回 true

get

public V get(Object rowKey,
 Object columnKey)

Description copied from interface: Table

Get the value at the specified row and column. 获取指定行列的值。

Specified by:

get in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

columnKey - the column key | 列键

Returns:

the value, or null | 值，或 null

put

public V put(R rowKey,
 C columnKey,
 V value)

Description copied from interface: Table

Put a value at the specified row and column. 在指定行列放入值。

Specified by:

put in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

columnKey - the column key | 列键

value - the value | 值

Returns:

previous value, or null | 之前的值，或 null

putAll

public void putAll(Table<? extends R, ? extends C, ? extends V> table)

Description copied from interface: Table

Put all values from another table. 从另一个表放入所有值。

Specified by:

putAll in interface Table<R,C,V>

Parameters:

table - the source table | 源表

remove

public V remove(Object rowKey,
 Object columnKey)

Description copied from interface: Table

Remove the value at the specified row and column. 移除指定行列的值。

Specified by:

remove in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

columnKey - the column key | 列键

Returns:

removed value, or null | 移除的值，或 null

rowKeySet

public Set<R> rowKeySet()

Description copied from interface: Table

Return a view of all row keys. 返回所有行键的视图。

Specified by:

rowKeySet in interface Table<R,C,V>

Returns:

row key set | 行键集合

columnKeySet

public Set<C> columnKeySet()

Description copied from interface: Table

Return a view of all column keys. 返回所有列键的视图。

Specified by:

columnKeySet in interface Table<R,C,V>

Returns:

column key set | 列键集合

values

public Collection<V> values()

Description copied from interface: Table

Return a view of all values. 返回所有值的视图。

Specified by:

values in interface Table<R,C,V>

Returns:

values collection | 值集合

cellSet

public Set<Table.Cell<R,C,V>> cellSet()

Description copied from interface: Table

Return a view of all cells. 返回所有单元格的视图。

Specified by:

cellSet in interface Table<R,C,V>

Returns:

cell set | 单元格集合

row

public Map<C,V> row(R rowKey)

Description copied from interface: Table

Return a map view for a specific row. 返回特定行的映射视图。

Specified by:

row in interface Table<R,C,V>

Parameters:

rowKey - the row key | 行键

Returns:

column to value map | 列到值的映射

column

public Map<R,V> column(C columnKey)

Description copied from interface: Table

Return a map view for a specific column. 返回特定列的映射视图。

Specified by:

column in interface Table<R,C,V>

Parameters:

columnKey - the column key | 列键

Returns:

row to value map | 行到值的映射

rowMap

public Map<R,Map<C,V>> rowMap()

Description copied from interface: Table

Return a map view of all rows. 返回所有行的映射视图。

Specified by:

rowMap in interface Table<R,C,V>

Returns:

row key to column-value map | 行键到列值映射

columnMap

public Map<C,Map<R,V>> columnMap()

Description copied from interface: Table

Return a map view of all columns. 返回所有列的映射视图。

Specified by:

columnMap in interface Table<R,C,V>

Returns:

column key to row-value map | 列键到行值映射

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object