com.yahoo.bullet.common

Class Utilities

java.lang.Object

com.yahoo.bullet.common.Utilities

public class Utilities
extends Object

Constructor Summary

Constructors

Constructor and Description
Utilities()

Method Summary

Modifier and Type	Method and Description
static Number	extractFieldAsNumber(String field, com.yahoo.bullet.record.BulletRecord record) Extracts the field from the given (@link BulletRecord} as a Number, if possible.
static double[]	generatePoints(double start, Function<Double,Double> generator, int numberOfPoints, int rounding) Generates an array of points from the given arguments.
static <U> U	getCasted(Map<String,Object> map, String key, Class<U> clazz) Tries to get a key from a map as the target type.
static <U> U	getCasted(Object entry, Class<U> clazz) Tries to get the object casted as the target type.
static boolean	isEmpty(Collection collection) Checks to see if the Collection contains any items.
static boolean	isEmpty(Map map) Checks to see if the Map contains any mappings.
static boolean	isEmpty(String string) Checks to see if the String is present.
static <S> S	loadConfiguredClass(String name, BulletConfig config) This method loads a given class name with the class name key and creates an instance of it by using a constructor that has a single argument for a BulletConfig.
static <K,V> Map<K,V>	putNotNull(Map<K,V> map, K key, V value) Adds the given mapping to the given Map if the value is not null.
static <T> List<T>	requireNonNull(List<T> list) Throws a NullPointerException if the List is null or contains any null elements.
static <K,V> Map<K,V>	requireNonNull(Map<K,V> map) Throws a NullPointerException if the Map is null or contains any null keys or null values.
static <T> Set<T>	requireNonNull(Set<T> set) Throws a NullPointerException if the Set is null or contains any null elements.
static double	round(double value, int places) Rounds a double up to the specified number of places.

Methods inherited from class java.lang.Object

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

Constructor Detail

Utilities

public Utilities()

Method Detail

getCasted

public static <U> U getCasted(Object entry,
                              Class<U> clazz)

Tries to get the object casted as the target type. If it is generic, the captured types cannot not be validated. Only the base object type is validated.

Type Parameters:

U - The type to get the object as.

Parameters:

entry - The object to cast.

clazz - The class of the U.

Returns:

The casted object of type U or null if the cast could not be done.

getCasted

public static <U> U getCasted(Map<String,Object> map,
                              String key,
                              Class<U> clazz)

Tries to get a key from a map as the target type. If it is a generic type, the captured types are not validated. Only the base object type is validated.

Type Parameters:

U - The type to get the object as.

Parameters:

map - The non-null map that possibly contains the key.

key - The String key to get the value for from the map.

clazz - The class of the U.

Returns:

The casted object of type U or null if the cast could not be done.

Throws:

NullPointerException - if the map was null.

isEmpty

public static boolean isEmpty(Map map)

Checks to see if the Map contains any mappings.

Parameters:

map - The map to check.

Returns:

A boolean denoting whether the map had mappings.

isEmpty

public static boolean isEmpty(Collection collection)

Checks to see if the Collection contains any items.

Parameters:

collection - The collection to check.

Returns:

A boolean denoting whether the collection had items.

isEmpty

public static boolean isEmpty(String string)

Checks to see if the String is present.

Parameters:

string - The string to check.

Returns:

A boolean denoting whether the string was present.

requireNonNull

public static <T> List<T> requireNonNull(List<T> list)

Throws a NullPointerException if the List is null or contains any null elements.

Type Parameters:

T - The type of the list.

Parameters:

list - The list to check.

Returns:

The list.

requireNonNull

public static <T> Set<T> requireNonNull(Set<T> set)

Throws a NullPointerException if the Set is null or contains any null elements.

Type Parameters:

T - The type of the set.

Parameters:

set - The set to check.

Returns:

The set.

requireNonNull

public static <K,V> Map<K,V> requireNonNull(Map<K,V> map)

Throws a NullPointerException if the Map is null or contains any null keys or null values.

Type Parameters:

K - The type of the map key.

V - The type of the map value.

Parameters:

map - The map to check.

Returns:

The map.

putNotNull

public static <K,V> Map<K,V> putNotNull(Map<K,V> map,
                                        K key,
                                        V value)

Adds the given mapping to the given Map if the value is not null.

Type Parameters:

K - The type of the map key.

V - The type of the map value.

Parameters:

map - The map to check.

key - The key to add.

value - The value to add if not null.

Returns:

The map.

round

public static double round(double value,
                           int places)

Rounds a double up to the specified number of places.

Parameters:

value - The number to round.

places - The number of maximum decimal places to round up to.

Returns:

The resulting rounded double.

generatePoints

public static double[] generatePoints(double start,
                                      Function<Double,Double> generator,
                                      int numberOfPoints,
                                      int rounding)

Generates an array of points from the given arguments.

Parameters:

start - The first point to begin with.

generator - A function that returns the next point given the previous.

numberOfPoints - The size of the resulting array.

rounding - The number of maximum decimal places to round up to.

Returns:

An array of points generated from the given arguments.

extractFieldAsNumber

public static Number extractFieldAsNumber(String field,
                                          com.yahoo.bullet.record.BulletRecord record)

Extracts the field from the given (@link BulletRecord} as a Number, if possible.

Parameters:

field - The field to get as a number.

record - The record containing the field.

Returns:

The value of the field as a Number or null if it cannot be forced to one.

loadConfiguredClass

public static <S> S loadConfiguredClass(String name,
                                        BulletConfig config)

This method loads a given class name with the class name key and creates an instance of it by using a constructor that has a single argument for a BulletConfig. It then passes in the provided config and returns the constructed instance.

Type Parameters:

S - The type of the class.

Parameters:

name - The name of class name to load.

config - The BulletConfig to use to create an instance of the class.

Returns:

A created instance of this class.

Throws:

RuntimeException - if there were issues creating an instance. It wraps the real exception.