1. 功能：简化表格操作，形似Excel的单元格操作；
2. 代码：
package com.example.google.guava.demo.collection;
import com.google.common.collect.HashBasedTable;
import com.google.common.collect.Table;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* <p>
* <code>TableTest</code>
* </p>
* Description: Table<R, C, V>接口类似Map<R,Map<C,V>>，R-row,C-column,V-value
*
* @author Mcchu
* @date 2017/10/20 8:25
*/
public class TableTest {
public static void main(String[] args) {
// 1.创建表格Table
Table<String, String, String> employeeTable = HashBasedTable.create();
// 2.初始化表格Table,参数分别对应表格的行、列、值
employeeTable.put("IBM", "101","Mahesh");
employeeTable.put("IBM", "102","Ramesh");
employeeTable.put("IBM", "103","Suresh");
employeeTable.put("Microsoft", "111","Sohan");
employeeTable.put("Microsoft", "112","Mohan");
employeeTable.put("Microsoft", "113","Rohan");
employeeTable.put("TCS", "121","Ram");
employeeTable.put("TCS", "122","Shyam");
employeeTable.put("TCS", "123","Sunil");
// 3.获取表格中某个单元格的值
String IBM103name = employeeTable.get("IBM","103");
System.out.println("3.行key为IBM列key为103的员工值："+IBM103name);
// 4.转换为Map，将Table<R,C,V>转换成Map<C,V>形势
Map<String,String> ibmEmployees = employeeTable.row("IBM");
System.out.println("4.IBM员工信息：");
for (Map.Entry<String,String> entry:ibmEmployees.entrySet()){
String id = entry.getKey();
String name = entry.getValue();
System.out.println(" 员工id："+ id +",员工姓名："+name);
}
// 5.键去重（即获取唯一）
Set<String> employeeRowKeys = employeeTable.rowKeySet();
System.out.println("5.获取表中所有唯一键：");
for (String rowKey: employeeRowKeys){
System.out.println(" 行号："+rowKey);
}
// 6.转换为Map，将Table<R,C,V>转换成Map<R,V>形式
Map<String,String> employerMap1 = employeeTable.column("102");
System.out.println("6.列102的数据：");
for ( Map.Entry<String,String> entry:employerMap1.entrySet() ){
String company = entry.getKey();
String name = entry.getValue();
System.out.println(" 公司名字："+company+",员工姓名"+name);
}
// 7.遍历表格
Set<Table.Cell<String,String,String>> tableSet = employeeTable.cellSet();
Iterator<Table.Cell<String,String,String>> it = tableSet.iterator();
System.out.println("7.遍历Table：");
while (it.hasNext()){
Table.Cell<String,String,String> data = it.next();
String rowCompany = data.getRowKey();
String columnId = data.getColumnKey();
String valueName = data.getValue();
System.out.println(" 行号："+rowCompany+",列号："+columnId+",值："+valueName);
}
// 8.获取列键
System.out.println("8.获取所有列键：");
for (String columnKey : employeeTable.columnKeySet()){
Map<String,String> rowAndValue = employeeTable.column(columnKey);
System.out.println(" 列："+columnKey+"对应的数据Map是："+rowAndValue);
}
// 9.
Collection<String> values = employeeTable.values();
System.out.println("9.获取所有值："+values.toString());
// 10.其他简单方法，不做尝试
//boolean contains(Object rowKey, Object columnKey)
//boolean containsColumn(Object columnKey)
//boolean containsRow(Object rowKey)
//boolean containsValue(Object value)
//boolean equals(Object obj)
//int hashCode()
//boolean isEmpty()
//void putAll(Table<? extends R,? extends C,? extends V> table)
//V remove(Object rowKey, Object columnKey)
//int size()
}
}
3. 输出结果：
3.行key为IBM列key为103的员工值：Suresh
4.IBM员工信息：
员工id：101,员工姓名：Mahesh
员工id：102,员工姓名：Ramesh
员工id：103,员工姓名：Suresh
5.获取表中所有唯一键：
行号：IBM
行号：Microsoft
行号：TCS
6.列102的数据：
公司名字：IBM,员工姓名Ramesh
7.遍历Table：
行号：IBM,列号：101,值：Mahesh
行号：IBM,列号：102,值：Ramesh
行号：IBM,列号：103,值：Suresh
行号：Microsoft,列号：111,值：Sohan
行号：Microsoft,列号：112,值：Mohan
行号：Microsoft,列号：113,值：Rohan
行号：TCS,列号：121,值：Ram
行号：TCS,列号：122,值：Shyam
行号：TCS,列号：123,值：Sunil
8.获取所有列键：
列：101对应的数据Map是：{IBM=Mahesh}
列：102对应的数据Map是：{IBM=Ramesh}
列：103对应的数据Map是：{IBM=Suresh}
列：111对应的数据Map是：{Microsoft=Sohan}
列：112对应的数据Map是：{Microsoft=Mohan}
列：113对应的数据Map是：{Microsoft=Rohan}
列：121对应的数据Map是：{TCS=Ram}
列：122对应的数据Map是：{TCS=Shyam}
列：123对应的数据Map是：{TCS=Sunil}
9.获取所有值：[Mahesh, Ramesh, Suresh, Sohan, Mohan, Rohan, Ram, Shyam, Sunil]
1.参考：http://www.yiibai.com/guava/guava_table.html
2.源码：
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.CompatibleWith;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A collection that associates an ordered pair of keys, called a row key and a
* column key, with a single value. A table may be sparse, with only a small
* fraction of row key / column key pairs possessing a corresponding value.
*
* <p>The mappings corresponding to a given row key may be viewed as a {@link
* Map} whose keys are the columns. The reverse is also available, associating a
* column with a row key / value map. Note that, in some implementations, data
* access by column key may have fewer supported operations or worse performance
* than data access by row key.
*
* <p>The methods returning collections or maps always return views of the
* underlying table. Updating the table can change the contents of those
* collections, and updating the collections will change the table.
*
* <p>All methods that modify the table are optional, and the views returned by
* the table may or may not be modifiable. When modification isn't supported,
* those methods will throw an {@link UnsupportedOperationException}.
*
* <p>See the Guava User Guide article on <a href=
* "https://github.com/google/guava/wiki/NewCollectionTypesExplained#table">
* {@code Table}</a>.
*
* @author Jared Levy
* @param <R> the type of the table row keys
* @param <C> the type of the table column keys
* @param <V> the type of the mapped values
* @since 7.0
*/
@GwtCompatible
public interface Table<R, C, V> {
// TODO(jlevy): Consider adding methods similar to ConcurrentMap methods.
// Accessors
/**
* Returns {@code true} if the table contains a mapping with the specified row and column keys.
*
* @param rowKey key of row to search for
* @param columnKey key of column to search for
*/
boolean contains(
@Nullable @CompatibleWith("R") Object rowKey,
@Nullable @CompatibleWith("C") Object columnKey);
/**
* Returns {@code true} if the table contains a mapping with the specified row key.
*
* @param rowKey key of row to search for
*/
boolean containsRow(@Nullable @CompatibleWith("R") Object rowKey);
/**
* Returns {@code true} if the table contains a mapping with the specified column.
*
* @param columnKey key of column to search for
*/
boolean containsColumn(@Nullable @CompatibleWith("C") Object columnKey);
/**
* Returns {@code true} if the table contains a mapping with the specified value.
*
* @param value value to search for
*/
boolean containsValue(@Nullable @CompatibleWith("V") Object value);
/**
* Returns the value corresponding to the given row and column keys, or {@code null} if no such
* mapping exists.
*
* @param rowKey key of row to search for
* @param columnKey key of column to search for
*/
V get(
@Nullable @CompatibleWith("R") Object rowKey,
@Nullable @CompatibleWith("C") Object columnKey);
/** Returns {@code true} if the table contains no mappings. */
boolean isEmpty();
/**
* Returns the number of row key / column key / value mappings in the table.
*/
int size();
/**
* Compares the specified object with this table for equality. Two tables are
* equal when their cell views, as returned by {@link #cellSet}, are equal.
*/
@Override
boolean equals(@Nullable Object obj);
/**
* Returns the hash code for this table. The hash code of a table is defined
* as the hash code of its cell view, as returned by {@link #cellSet}.
*/
@Override
int hashCode();
// Mutators
/** Removes all mappings from the table. */
void clear();
/**
* Associates the specified value with the specified keys. If the table
* already contained a mapping for those keys, the old value is replaced with
* the specified value.
*
* @param rowKey row key that the value should be associated with
* @param columnKey column key that the value should be associated with
* @param value value to be associated with the specified keys
* @return the value previously associated with the keys, or {@code null} if
* no mapping existed for the keys
*/
@CanIgnoreReturnValue
@Nullable
V put(R rowKey, C columnKey, V value);
/**
* Copies all mappings from the specified table to this table. The effect is
* equivalent to calling {@link #put} with each row key / column key / value
* mapping in {@code table}.
*
* @param table the table to add to this table
*/
void putAll(Table<? extends R, ? extends C, ? extends V> table);
/**
* Removes the mapping, if any, associated with the given keys.
*
* @param rowKey row key of mapping to be removed
* @param columnKey column key of mapping to be removed
* @return the value previously associated with the keys, or {@code null} if no such value existed
*/
@CanIgnoreReturnValue
@Nullable
V remove(
@Nullable @CompatibleWith("R") Object rowKey,
@Nullable @CompatibleWith("C") Object columnKey);
// Views
/**
* Returns a view of all mappings that have the given row key. For each row
* key / column key / value mapping in the table with that row key, the
* returned map associates the column key with the value. If no mappings in
* the table have the provided row key, an empty map is returned.
*
* <p>Changes to the returned map will update the underlying table, and vice
* versa.
*
* @param rowKey key of row to search for in the table
* @return the corresponding map from column keys to values
*/
Map<C, V> row(R rowKey);
/**
* Returns a view of all mappings that have the given column key. For each row
* key / column key / value mapping in the table with that column key, the
* returned map associates the row key with the value. If no mappings in the
* table have the provided column key, an empty map is returned.
*
* <p>Changes to the returned map will update the underlying table, and vice
* versa.
*
* @param columnKey key of column to search for in the table
* @return the corresponding map from row keys to values
*/
Map<R, V> column(C columnKey);
/**
* Returns a set of all row key / column key / value triplets. Changes to the
* returned set will update the underlying table, and vice versa. The cell set
* does not support the {@code add} or {@code addAll} methods.
*
* @return set of table cells consisting of row key / column key / value
* triplets
*/
Set<Cell<R, C, V>> cellSet();
/**
* Returns a set of row keys that have one or more values in the table.
* Changes to the set will update the underlying table, and vice versa.
*
* @return set of row keys
*/
Set<R> rowKeySet();
/**
* Returns a set of column keys that have one or more values in the table.
* Changes to the set will update the underlying table, and vice versa.
*
* @return set of column keys
*/
Set<C> columnKeySet();
/**
* Returns a collection of all values, which may contain duplicates. Changes
* to the returned collection will update the underlying table, and vice
* versa.
*
* @return collection of values
*/
Collection<V> values();
/**
* Returns a view that associates each row key with the corresponding map from
* column keys to values. Changes to the returned map will update this table.
* The returned map does not support {@code put()} or {@code putAll()}, or
* {@code setValue()} on its entries.
*
* <p>In contrast, the maps returned by {@code rowMap().get()} have the same
* behavior as those returned by {@link #row}. Those maps may support {@code
* setValue()}, {@code put()}, and {@code putAll()}.
*
* @return a map view from each row key to a secondary map from column keys to
* values
*/
Map<R, Map<C, V>> rowMap();
/**
* Returns a view that associates each column key with the corresponding map
* from row keys to values. Changes to the returned map will update this
* table. The returned map does not support {@code put()} or {@code putAll()},
* or {@code setValue()} on its entries.
*
* <p>In contrast, the maps returned by {@code columnMap().get()} have the
* same behavior as those returned by {@link #column}. Those maps may support
* {@code setValue()}, {@code put()}, and {@code putAll()}.
*
* @return a map view from each column key to a secondary map from row keys to
* values
*/
Map<C, Map<R, V>> columnMap();
/**
* Row key / column key / value triplet corresponding to a mapping in a table.
*
* @since 7.0
*/
interface Cell<R, C, V> {
/**
* Returns the row key of this cell.
*/
@Nullable
R getRowKey();
/**
* Returns the column key of this cell.
*/
@Nullable
C getColumnKey();
/**
* Returns the value of this cell.
*/
@Nullable
V getValue();
/**
* Compares the specified object with this cell for equality. Two cells are
* equal when they have equal row keys, column keys, and values.
*/
@Override
boolean equals(@Nullable Object obj);
/**
* Returns the hash code of this cell.
*
* <p>The hash code of a table cell is equal to {@link
* Objects#hashCode}{@code (e.getRowKey(), e.getColumnKey(), e.getValue())}.
*/
@Override
int hashCode();
}
}