com.yahoo.bard.webservice.util

Class Utils

java.lang.Object

com.yahoo.bard.webservice.util.Utils

public class Utils
extends Object

Utils.

Constructor Summary

Constructors

Constructor and Description
Utils()

Method Summary

Modifier and Type	Method and Description
static void	addToMetricDictionary(MetricDictionary metricDictionary, List<MetricInstance> metrics) Create metrics from instance descriptors and store in the metric dictionary.
static <E> LinkedHashSet<E>	asLinkedHashSet(E... e) Easily turn a few instances of an object into a LinkedHashSet.
static void	createParentDirectories(String path) Create parent directories if they don't exist in a given file path.
static void	deleteFiles(String path) Delete files or directories in the specified path.
static <T extends Comparable> T	getMinValue(T one, T two) Find the minimum value between two comparable objects.
static <T,K extends T> LinkedHashSet<K>	getSubsetByType(Collection<T> set, Class<K> type) Given a collection of objects which share the same super class, return the subset of objects that share a common sub class.
static javax.ws.rs.core.MultivaluedMap<String,String>	headersToLowerCase(javax.ws.rs.core.MultivaluedMap<String,String> headers) Helper method to return request headers as a map of the same type with its keys lower cased.
static <T> T	insteadThrowRuntime(RuntimeException exception) Helper method to throw an exception when a result is expected as a return value (e.g.
static void	omitField(com.fasterxml.jackson.databind.JsonNode node, String fieldName, com.fasterxml.jackson.databind.ObjectMapper mapper) Given a field name and a tree of json nodes, empty the contents of all the json nodes matching the field name.
static <T,U,V> org.apache.commons.lang3.tuple.ImmutablePair<T,V>	withRight(org.apache.commons.lang3.tuple.ImmutablePair<T,U> pair, V right) Given an ImmutablePair, and a right value, returns a new ImmutablePair with the same left value, and the specified right value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Utils

public Utils()

Method Detail

getSubsetByType

public static <T,K extends T> LinkedHashSet<K> getSubsetByType(Collection<T> set,
                                                               Class<K> type)

Given a collection of objects which share the same super class, return the subset of objects that share a common sub class.

Type Parameters:

T - Input set type

K - sub class type

Parameters:

set - Input set

type - sub class

Returns:

ordered subset of objects that share a common sub class

asLinkedHashSet

@SafeVarargs
public static <E> LinkedHashSet<E> asLinkedHashSet(E... e)

Easily turn a few instances of an object into a LinkedHashSet.

 LinkedHashSet<String> stooges = Utils.asLinkedHashSet("Larry", "Moe", "Curly");
 

Type Parameters:

E - The element type for the linked hash set

Parameters:

e - The array from which the LinkedHashSet will be built

Returns:

a LinkedHashSet view of the specified array

createParentDirectories

public static void createParentDirectories(String path)

Create parent directories if they don't exist in a given file path.

Parameters:

path - The pathname

deleteFiles

public static void deleteFiles(String path)

Delete files or directories in the specified path.

Parameters:

path - The pathname

insteadThrowRuntime

public static <T> T insteadThrowRuntime(RuntimeException exception)

Helper method to throw an exception when a result is expected as a return value (e.g. in a ternary operator)

Type Parameters:

T - The type of exception being returned

Parameters:

exception - The exception to be thrown

Returns:

is only used for type inference. No object is actually ever returned. An exception is always being thrown instead

headersToLowerCase

public static javax.ws.rs.core.MultivaluedMap<String,String> headersToLowerCase(javax.ws.rs.core.MultivaluedMap<String,String> headers)

Helper method to return request headers as a map of the same type with its keys lower cased.

Parameters:

headers - The request headers.

Returns:

The headers with their names lower cased.

omitField

public static void omitField(com.fasterxml.jackson.databind.JsonNode node,
                             String fieldName,
                             com.fasterxml.jackson.databind.ObjectMapper mapper)

Given a field name and a tree of json nodes, empty the contents of all the json nodes matching the field name. This method is recursive.

Parameters:

node - The root of the tree of json nodes.

fieldName - The name of the node to be omitted.

mapper - The object mapper that creates and empty node.

getMinValue

public static <T extends Comparable> T getMinValue(T one,
                                                   T two)

Find the minimum value between two comparable objects.

Type Parameters:

T - Type of object to compare

Parameters:

one - Item 1

two - Item 2

Returns:

the minimum of the two objects

withRight

public static <T,U,V> org.apache.commons.lang3.tuple.ImmutablePair<T,V> withRight(org.apache.commons.lang3.tuple.ImmutablePair<T,U> pair,
                                                                                  V right)

Given an ImmutablePair, and a right value, returns a new ImmutablePair with the same left value, and the specified right value.

Type Parameters:

T - Left type of the pair

U - Right type of the pair

V - The right value to have new Immutable Pair

Parameters:

pair - Immutable Pair instance

right - The right value, may be null

Returns:

New instance of Immutable Pair

addToMetricDictionary

public static void addToMetricDictionary(MetricDictionary metricDictionary,
                                         List<MetricInstance> metrics)

Create metrics from instance descriptors and store in the metric dictionary.

Parameters:

metricDictionary - The dictionary to store metrics in

metrics - The list of metric descriptors