Package tech.tablesaw.sorting

Class Sort

java.lang.Object

tech.tablesaw.sorting.Sort

All Implemented Interfaces:

Iterable<Map.Entry<String,Sort.Order>>

public class Sort
extends Object
implements Iterable<Map.Entry<String,Sort.Order>>

Provides fine-grained control over sorting.

Use:

table.sortOn(first("Year", DESCEND).next("State", ASCEND));

This sorts table on the column named year in descending order, such that the most recent years appear first, then on State, in ascending order so "AL" will appear before "CA". You can add additional instructions for multi-column sorts by chaining additional calls to next() with the appropriate column names and Order.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Sort.Order

Constructor Summary

Constructors

Constructor	Description
Sort(String columnName, Sort.Order order)	Constructs a Sort specifying the order (ascending or descending) to apply to the column with the given name

Method Summary

Modifier and Type	Method	Description
static Sort	create(Table table, String... columnNames)	Create a Sort object from the given table and sort column names.
boolean	isEmpty()	Returns true if no order has been set
Iterator<Map.Entry<String,Sort.Order>>	iterator()	Returns an iterator over elements of type T.
Sort	next(String columnName, Sort.Order order)	Returns a Sort that concatenates a new sort on the given order (ascending or descending) and columnName onto the sort specified here.
static Sort	on(String columnName, Sort.Order order)	Returns a Sort specifying the order (ascending or descending) to apply to the column with the given name
int	size()	Returns the number of columns used in this sort
String	toString()

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Sort

public Sort(String columnName,
            Sort.Order order)

Constructs a Sort specifying the order (ascending or descending) to apply to the column with the given name

Method Detail

on

public static Sort on(String columnName,
                      Sort.Order order)

Returns a Sort specifying the order (ascending or descending) to apply to the column with the given name

next

public Sort next(String columnName,
                 Sort.Order order)

Returns a Sort that concatenates a new sort on the given order (ascending or descending) and columnName onto the sort specified here. This method is used to construct complex sorts such as: Sort.on("foo", Order.ASCEND).next("bar", Order.DESCEND);

isEmpty

public boolean isEmpty()

Returns true if no order has been set

size

public int size()

Returns the number of columns used in this sort

create

public static Sort create(Table table,
                          String... columnNames)

Create a Sort object from the given table and sort column names. Does not sort the table.

Parameters:

table - to sort. Used only to pull the table's schema. Does not modify the table.

columnNames - The columns to sort on. Can prefix column name with + for ascending, - for descending. Default to ascending if no prefix is added.

Returns:

a Sort(java.lang.String, tech.tablesaw.sorting.Sort.Order) Object.

iterator

public Iterator<Map.Entry<String,Sort.Order>> iterator()

Returns an iterator over elements of type T.

Specified by:

iterator in interface Iterable<Map.Entry<String,Sort.Order>>

Returns:

an Iterator.

toString

public String toString()

Overrides:

toString in class Object