org.apache.drill.exec.alias

Class EmptyAliases

java.lang.Object

org.apache.drill.exec.alias.EmptyAliases

All Implemented Interfaces:

Aliases

public class EmptyAliases
extends Object
implements Aliases

Implementation of aliases table that doesn't hold or return information.

Field Summary

Fields

Modifier and Type	Field and Description
static EmptyAliases	INSTANCE

Constructor Summary

Constructors

Constructor and Description
EmptyAliases()

Method Summary

Modifier and Type	Method and Description
String	get(String alias) Returns value from aliases table that corresponds to provided alias.
Iterator<Map.Entry<String,String>>	getAllAliases() Returns iterator for all entries of this aliases table.
String	getKey() Key of this aliases table.
boolean	put(String alias, String value, boolean replace) Associates provided alias with provided alias in aliases table.
boolean	remove(String alias) Removes value for specified alias from aliases table.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final EmptyAliases INSTANCE

Constructor Detail

EmptyAliases

public EmptyAliases()

Method Detail

getKey

public String getKey()

Description copied from interface: Aliases

Key of this aliases table.

Specified by:

getKey in interface Aliases

get

public String get(String alias)

Description copied from interface: Aliases

Returns value from aliases table that corresponds to provided alias.

Specified by:

get in interface Aliases

Parameters:

alias - alias of the value to obtain

Returns:

value from aliases table that corresponds to provided alias

put

public boolean put(String alias,
                   String value,
                   boolean replace)

Description copied from interface: Aliases

Associates provided alias with provided alias in aliases table.

Specified by:

put in interface Aliases

Parameters:

alias - alias of the value to associate with

value - value that will be associated with provided alias

replace - whether existing value for the same alias should be replaced

Returns:

true if provided alias was associated with the provided value in aliases table

remove

public boolean remove(String alias)

Description copied from interface: Aliases

Removes value for specified alias from aliases table.

Specified by:

remove in interface Aliases

Parameters:

alias - alias of the value to remove

Returns:

true if the value associated with provided alias was removed from the aliases table

getAllAliases

public Iterator<Map.Entry<String,String>> getAllAliases()

Description copied from interface: Aliases

Returns iterator for all entries of this aliases table.

Specified by:

getAllAliases in interface Aliases