#184 Fluent interface pattern, added uml, adjusted style, added pattern description
This commit is contained in:
parent
ee47ae021a
commit
fb13ddc5d6
4
faq.md
4
faq.md
@ -61,3 +61,7 @@ As for performance and scalability, pools can become bottlenecks, if all the
|
||||
pooled objects are in use and more clients need them, threads will become
|
||||
blocked waiting for available object from the pool. This is not the case with
|
||||
Flyweight.
|
||||
|
||||
### Q7: What are the differences between FluentInterface and Builder patterns? {#Q7}
|
||||
|
||||
Fluent interfaces are sometimes confused with the Builder pattern, because they share method chaining and a fluent usage. However, fluent interfaces are not primarily used to create shared (mutable) objects, but to configure complex objects without having to respecify the target object on every property change.
|
BIN
fluentinterface/etc/fluentinterface.png
Normal file
BIN
fluentinterface/etc/fluentinterface.png
Normal file
Binary file not shown.
After Width: | Height: | Size: 58 KiB |
100
fluentinterface/etc/fluentinterface.ucls
Normal file
100
fluentinterface/etc/fluentinterface.ucls
Normal file
@ -0,0 +1,100 @@
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true"
|
||||
realizations="true" associations="true" dependencies="false" nesting-relationships="true">
|
||||
<class id="1" language="java" name="com.iluwatar.fluentinterface.App" project="fluentinterface"
|
||||
file="/fluentinterface/src/main/java/com/iluwatar/fluentinterface/App.java" binary="false" corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="289" y="-8"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</class>
|
||||
<class id="2" language="java" name="com.iluwatar.fluentinterface.fluentiterable.simple.SimpleFluentIterable"
|
||||
project="fluentinterface"
|
||||
file="/fluentinterface/src/main/java/com/iluwatar/fluentinterface/fluentiterable/simple/SimpleFluentIterable.java"
|
||||
binary="false" corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="450" y="430"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</class>
|
||||
<class id="3" language="java" name="com.iluwatar.fluentinterface.fluentiterable.lazy.LazyFluentIterable"
|
||||
project="fluentinterface"
|
||||
file="/fluentinterface/src/main/java/com/iluwatar/fluentinterface/fluentiterable/lazy/LazyFluentIterable.java"
|
||||
binary="false" corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="860" y="391"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</class>
|
||||
<interface id="4" language="java" name="com.iluwatar.fluentinterface.fluentiterable.FluentIterable"
|
||||
project="fluentinterface"
|
||||
file="/fluentinterface/src/main/java/com/iluwatar/fluentinterface/fluentiterable/FluentIterable.java" binary="false"
|
||||
corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="794" y="55"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</interface>
|
||||
<class id="5" language="java" name="com.iluwatar.fluentinterface.fluentiterable.lazy.DecoratingIterator"
|
||||
project="fluentinterface"
|
||||
file="/fluentinterface/src/main/java/com/iluwatar/fluentinterface/fluentiterable/lazy/DecoratingIterator.java"
|
||||
binary="false" corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="1245" y="391"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</class>
|
||||
<interface id="6" language="java" name="java.lang.Iterable" project="fluentinterface"
|
||||
file="C:/Program Files/Java/jdk1.8.0/jre/lib/rt.jar" binary="true" corner="BOTTOM_RIGHT">
|
||||
<position height="-1" width="-1" x="793" y="-163"/>
|
||||
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</display>
|
||||
</interface>
|
||||
<dependency id="7">
|
||||
<end type="SOURCE" refId="1"/>
|
||||
<end type="TARGET" refId="3"/>
|
||||
</dependency>
|
||||
<dependency id="8">
|
||||
<end type="SOURCE" refId="1"/>
|
||||
<end type="TARGET" refId="2"/>
|
||||
</dependency>
|
||||
<generalization id="9">
|
||||
<end type="SOURCE" refId="4"/>
|
||||
<end type="TARGET" refId="6"/>
|
||||
</generalization>
|
||||
<realization id="10">
|
||||
<end type="SOURCE" refId="3"/>
|
||||
<end type="TARGET" refId="4"/>
|
||||
</realization>
|
||||
<dependency id="11">
|
||||
<end type="SOURCE" refId="1"/>
|
||||
<end type="TARGET" refId="4"/>
|
||||
</dependency>
|
||||
<realization id="12">
|
||||
<end type="SOURCE" refId="2"/>
|
||||
<end type="TARGET" refId="4"/>
|
||||
</realization>
|
||||
<dependency id="13">
|
||||
<end type="SOURCE" refId="3"/>
|
||||
<end type="TARGET" refId="5"/>
|
||||
</dependency>
|
||||
<classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
|
||||
sort-features="false" accessors="true" visibility="true">
|
||||
<attributes public="true" package="true" protected="true" private="true" static="true"/>
|
||||
<operations public="true" package="true" protected="true" private="true" static="true"/>
|
||||
</classifier-display>
|
||||
<association-display labels="true" multiplicity="true"/>
|
||||
</class-diagram>
|
28
fluentinterface/index.md
Normal file
28
fluentinterface/index.md
Normal file
@ -0,0 +1,28 @@
|
||||
---
|
||||
layout: pattern
|
||||
title: Fluent Interface
|
||||
folder: fluentinterface
|
||||
permalink: /patterns/fluentinterface/
|
||||
categories: Architectural
|
||||
tags: Java
|
||||
---
|
||||
|
||||
**Intent:** A fluent interface provides an easy-readable, flowing interface, that often mimics a domain specific language. Using this pattern results in code that can be read nearly as human language.
|
||||
|
||||

|
||||
|
||||
**Applicability:** Use the Fluent Interface pattern when
|
||||
|
||||
* you provide an API that would benefit from a DSL-like usage
|
||||
* you have objects that are difficult to configure or use
|
||||
|
||||
**Real world examples:**
|
||||
|
||||
* [Java 8 Stream API](http://www.oracle.com/technetwork/articles/java/ma14-java-se-8-streams-2177646.html)
|
||||
* [Google Guava FluentInterable](https://github.com/google/guava/wiki/FunctionalExplained)
|
||||
* [JOOQ](http://www.jooq.org/doc/3.0/manual/getting-started/use-cases/jooq-as-a-standalone-sql-builder/)
|
||||
|
||||
**Credits**
|
||||
|
||||
* [Fluent Interface - Martin Fowler](http://www.martinfowler.com/bliki/FluentInterface.html)
|
||||
* [Evolutionary architecture and emergent design: Fluent interfaces - Neal Ford](http://www.ibm.com/developerworks/library/j-eaed14/)
|
@ -5,7 +5,7 @@
|
||||
<parent>
|
||||
<artifactId>java-design-patterns</artifactId>
|
||||
<groupId>com.iluwatar</groupId>
|
||||
<version>1.5.0</version>
|
||||
<version>1.6.0</version>
|
||||
</parent>
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
|
||||
|
@ -1,5 +1,6 @@
|
||||
package com.iluwatar.fluentinterface;
|
||||
|
||||
import com.iluwatar.fluentinterface.fluentiterable.FluentIterable;
|
||||
import com.iluwatar.fluentinterface.fluentiterable.lazy.LazyFluentIterable;
|
||||
import com.iluwatar.fluentinterface.fluentiterable.simple.SimpleFluentIterable;
|
||||
|
||||
@ -9,11 +10,23 @@ import java.util.function.Predicate;
|
||||
|
||||
import static java.lang.String.valueOf;
|
||||
|
||||
/**
|
||||
* Fluent interface pattern is useful when you want to provide an easy readable, flowing API. Those
|
||||
* interfaces tend to mimic domain specific languages, so they can nearly be read as human
|
||||
* languages.
|
||||
* <p>
|
||||
* In this example two implementations of a {@link FluentIterable} interface are given. The
|
||||
* SimpleFluentIterable evaluates eagerly and would be too costly for real world applications. The
|
||||
* LazyFluentIterable is evaluated on termination. Their usage is demonstrated with a simple number
|
||||
* list that is filtered, transformed and collected. The result is printed afterwards.
|
||||
* <p>
|
||||
*/
|
||||
public class App {
|
||||
|
||||
public static void main(String[] args) {
|
||||
|
||||
List<Integer> integerList = new ArrayList<Integer>() {{
|
||||
List<Integer> integerList = new ArrayList<Integer>() {
|
||||
{
|
||||
add(1);
|
||||
add(-61);
|
||||
add(14);
|
||||
@ -31,56 +44,59 @@ public class App {
|
||||
add(2);
|
||||
add(-68);
|
||||
add(45);
|
||||
}};
|
||||
}
|
||||
};
|
||||
prettyPrint("The initial list contains: ", integerList);
|
||||
|
||||
List<Integer> firstFiveNegatives = SimpleFluentIterable.from(integerList)
|
||||
.filter(negatives())
|
||||
.first(3)
|
||||
.asList();
|
||||
List<Integer> firstFiveNegatives =
|
||||
SimpleFluentIterable.fromCopyOf(integerList).filter(negatives()).first(3).asList();
|
||||
prettyPrint("The first three negative values are: ", firstFiveNegatives);
|
||||
|
||||
|
||||
List<Integer> lastTwoPositives = SimpleFluentIterable.from(integerList)
|
||||
.filter(positives())
|
||||
.last(2)
|
||||
.asList();
|
||||
List<Integer> lastTwoPositives =
|
||||
SimpleFluentIterable.fromCopyOf(integerList).filter(positives()).last(2).asList();
|
||||
prettyPrint("The last two positive values are: ", lastTwoPositives);
|
||||
|
||||
SimpleFluentIterable.from(integerList)
|
||||
SimpleFluentIterable
|
||||
.fromCopyOf(integerList)
|
||||
.filter(number -> number % 2 == 0)
|
||||
.first()
|
||||
.ifPresent(evenNumber -> System.out.println(String.format("The first even number is: %d", evenNumber)));
|
||||
.ifPresent(
|
||||
evenNumber -> System.out.println(String.format("The first even number is: %d",
|
||||
evenNumber)));
|
||||
|
||||
|
||||
List<String> transformedList = SimpleFluentIterable.from(integerList)
|
||||
.filter(negatives())
|
||||
.map(transformToString())
|
||||
List<String> transformedList =
|
||||
SimpleFluentIterable.fromCopyOf(integerList).filter(negatives()).map(transformToString())
|
||||
.asList();
|
||||
prettyPrint("A string-mapped list of negative numbers contains: ", transformedList);
|
||||
|
||||
|
||||
List<String> lastTwoOfFirstFourStringMapped = LazyFluentIterable.from(integerList)
|
||||
.filter(positives())
|
||||
.first(4)
|
||||
.last(2)
|
||||
.map(number -> "String[" + String.valueOf(number) + "]")
|
||||
.asList();
|
||||
prettyPrint("The lazy list contains the last two of the first four positive numbers mapped to Strings: ", lastTwoOfFirstFourStringMapped);
|
||||
List<String> lastTwoOfFirstFourStringMapped =
|
||||
LazyFluentIterable.from(integerList).filter(positives()).first(4).last(2)
|
||||
.map(number -> "String[" + String.valueOf(number) + "]").asList();
|
||||
prettyPrint(
|
||||
"The lazy list contains the last two of the first four positive numbers mapped to Strings: ",
|
||||
lastTwoOfFirstFourStringMapped);
|
||||
|
||||
LazyFluentIterable.from(integerList)
|
||||
LazyFluentIterable
|
||||
.from(integerList)
|
||||
.filter(negatives())
|
||||
.first(2)
|
||||
.last()
|
||||
.ifPresent(lastOfFirstTwo -> System.out.println(String.format("The last of the first two negatives is: %d", lastOfFirstTwo)));
|
||||
.ifPresent(
|
||||
lastOfFirstTwo -> System.out.println(String.format(
|
||||
"The last of the first two negatives is: %d", lastOfFirstTwo)));
|
||||
}
|
||||
|
||||
private static Function<Integer, String> transformToString() {
|
||||
return integer -> "String[" + valueOf(integer) + "]";
|
||||
}
|
||||
|
||||
private static Predicate<? super Integer> negatives() {
|
||||
return integer -> (integer < 0);
|
||||
}
|
||||
|
||||
private static Predicate<? super Integer> positives() {
|
||||
return integer -> (integer > 0);
|
||||
}
|
||||
@ -88,11 +104,13 @@ public class App {
|
||||
private static <TYPE> void prettyPrint(String prefix, Iterable<TYPE> iterable) {
|
||||
prettyPrint(", ", prefix, ".", iterable);
|
||||
}
|
||||
|
||||
private static <TYPE> void prettyPrint(String prefix, String suffix, Iterable<TYPE> iterable) {
|
||||
prettyPrint(", ", prefix, suffix, iterable);
|
||||
}
|
||||
|
||||
private static <TYPE> void prettyPrint(String delimiter, String prefix, String suffix, Iterable<TYPE> iterable) {
|
||||
private static <TYPE> void prettyPrint(String delimiter, String prefix, String suffix,
|
||||
Iterable<TYPE> iterable) {
|
||||
StringJoiner joiner = new StringJoiner(delimiter, prefix, ".");
|
||||
Iterator<TYPE> iterator = iterable.iterator();
|
||||
while (iterator.hasNext()) {
|
||||
|
@ -8,49 +8,56 @@ import java.util.function.Function;
|
||||
import java.util.function.Predicate;
|
||||
|
||||
/**
|
||||
* The FluentIterable is a more convenient implementation of the common iterable interface based
|
||||
* on the fluent interface design pattern.
|
||||
* This interface defines common operations, but
|
||||
* doesn't aim to be complete. It was inspired by Guava's com.google.common.collect.FluentIterable.
|
||||
* The FluentIterable is a more convenient implementation of the common iterable interface based on
|
||||
* the fluent interface design pattern. This interface defines common operations, but doesn't aim to
|
||||
* be complete. It was inspired by Guava's com.google.common.collect.FluentIterable.
|
||||
*
|
||||
* @param <TYPE> is the class of objects the iterable contains
|
||||
*/
|
||||
public interface FluentIterable<TYPE> extends Iterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy the predicate.
|
||||
* @param predicate the condition to test with for the filtering. If the test
|
||||
* is negative, the tested object is removed by the iterator.
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy
|
||||
* the predicate.
|
||||
*
|
||||
* @param predicate the condition to test with for the filtering. If the test is negative, the
|
||||
* tested object is removed by the iterator.
|
||||
* @return a filtered FluentIterable
|
||||
*/
|
||||
FluentIterable<TYPE> filter(Predicate<? super TYPE> predicate);
|
||||
|
||||
/**
|
||||
* Returns an Optional containing the first element of this iterable if present,
|
||||
* else returns Optional.empty().
|
||||
* Returns an Optional containing the first element of this iterable if present, else returns
|
||||
* Optional.empty().
|
||||
*
|
||||
* @return the first element after the iteration is evaluated
|
||||
*/
|
||||
Optional<TYPE> first();
|
||||
|
||||
/**
|
||||
* Evaluates the iteration and leaves only the count first elements.
|
||||
*
|
||||
* @return the first count elements as an Iterable
|
||||
*/
|
||||
FluentIterable<TYPE> first(int count);
|
||||
|
||||
/**
|
||||
* Evaluates the iteration and returns the last element. This is a terminating operation.
|
||||
*
|
||||
* @return the last element after the iteration is evaluated
|
||||
*/
|
||||
Optional<TYPE> last();
|
||||
|
||||
/**
|
||||
* Evaluates the iteration and leaves only the count last elements.
|
||||
*
|
||||
* @return the last counts elements as an Iterable
|
||||
*/
|
||||
FluentIterable<TYPE> last(int count);
|
||||
|
||||
/**
|
||||
* Transforms this FluentIterable into a new one containing objects of the type NEW_TYPE.
|
||||
*
|
||||
* @param function a function that transforms an instance of TYPE into an instance of NEW_TYPE
|
||||
* @param <NEW_TYPE> the target type of the transformation
|
||||
* @return a new FluentIterable of the new type
|
||||
@ -59,12 +66,14 @@ public interface FluentIterable<TYPE> extends Iterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Returns the contents of this Iterable as a List.
|
||||
*
|
||||
* @return a List representation of this Iterable
|
||||
*/
|
||||
List<TYPE> asList();
|
||||
|
||||
/**
|
||||
* Utility method that iterates over iterable and adds the contents to a list.
|
||||
*
|
||||
* @param iterable the iterable to collect
|
||||
* @param <TYPE> the type of the objects to iterate
|
||||
* @return a list with all objects of the given iterator
|
||||
|
@ -3,8 +3,9 @@ package com.iluwatar.fluentinterface.fluentiterable.lazy;
|
||||
import java.util.Iterator;
|
||||
|
||||
/**
|
||||
* This class is used to realize LazyFluentIterables. It decorates
|
||||
* a given iterator. Does not support consecutive hasNext() calls.
|
||||
* This class is used to realize LazyFluentIterables. It decorates a given iterator. Does not
|
||||
* support consecutive hasNext() calls.
|
||||
*
|
||||
* @param <TYPE>
|
||||
*/
|
||||
public abstract class DecoratingIterator<TYPE> implements Iterator<TYPE> {
|
||||
@ -15,6 +16,7 @@ public abstract class DecoratingIterator<TYPE> implements Iterator<TYPE> {
|
||||
|
||||
/**
|
||||
* Creates an iterator that decorates the given iterator.
|
||||
*
|
||||
* @param fromIterator
|
||||
*/
|
||||
public DecoratingIterator(Iterator<TYPE> fromIterator) {
|
||||
@ -23,6 +25,7 @@ public abstract class DecoratingIterator<TYPE> implements Iterator<TYPE> {
|
||||
|
||||
/**
|
||||
* Precomputes and saves the next element of the Iterable. null is considered as end of data.
|
||||
*
|
||||
* @return true if a next element is available
|
||||
*/
|
||||
@Override
|
||||
@ -33,6 +36,7 @@ public abstract class DecoratingIterator<TYPE> implements Iterator<TYPE> {
|
||||
|
||||
/**
|
||||
* Returns the next element of the Iterable.
|
||||
*
|
||||
* @return the next element of the Iterable, or null if not present.
|
||||
*/
|
||||
@Override
|
||||
@ -47,8 +51,9 @@ public abstract class DecoratingIterator<TYPE> implements Iterator<TYPE> {
|
||||
}
|
||||
|
||||
/**
|
||||
* Computes the next object of the Iterable. Can be implemented to
|
||||
* realize custom behaviour for an iteration process. null is considered as end of data.
|
||||
* Computes the next object of the Iterable. Can be implemented to realize custom behaviour for an
|
||||
* iteration process. null is considered as end of data.
|
||||
*
|
||||
* @return the next element of the Iterable.
|
||||
*/
|
||||
public abstract TYPE computeNext();
|
||||
|
@ -11,8 +11,9 @@ import java.util.function.Function;
|
||||
import java.util.function.Predicate;
|
||||
|
||||
/**
|
||||
* This is a lazy implementation of the FluentIterable interface. It evaluates
|
||||
* all chained operations when a terminating operation is applied.
|
||||
* This is a lazy implementation of the FluentIterable interface. It evaluates all chained
|
||||
* operations when a terminating operation is applied.
|
||||
*
|
||||
* @param <TYPE> the type of the objects the iteration is about
|
||||
*/
|
||||
public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
@ -20,8 +21,8 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
private final Iterable<TYPE> iterable;
|
||||
|
||||
/**
|
||||
* This constructor creates a new LazyFluentIterable. It wraps the
|
||||
* given iterable.
|
||||
* This constructor creates a new LazyFluentIterable. It wraps the given iterable.
|
||||
*
|
||||
* @param iterable the iterable this FluentIterable works on.
|
||||
*/
|
||||
protected LazyFluentIterable(Iterable<TYPE> iterable) {
|
||||
@ -29,17 +30,18 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
}
|
||||
|
||||
/**
|
||||
* This constructor can be used to implement anonymous subclasses
|
||||
* of the LazyFluentIterable.
|
||||
* This constructor can be used to implement anonymous subclasses of the LazyFluentIterable.
|
||||
*/
|
||||
protected LazyFluentIterable() {
|
||||
iterable = this;
|
||||
}
|
||||
|
||||
/**
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy the predicate.
|
||||
* @param predicate the condition to test with for the filtering. If the test
|
||||
* is negative, the tested object is removed by the iterator.
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy
|
||||
* the predicate.
|
||||
*
|
||||
* @param predicate the condition to test with for the filtering. If the test is negative, the
|
||||
* tested object is removed by the iterator.
|
||||
* @return a new FluentIterable object that decorates the source iterable
|
||||
*/
|
||||
@Override
|
||||
@ -67,6 +69,7 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the iteration. Is a terminating operation.
|
||||
*
|
||||
* @return an Optional containing the first object of this Iterable
|
||||
*/
|
||||
@Override
|
||||
@ -77,8 +80,10 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the iteration.
|
||||
*
|
||||
* @param count defines the number of objects to return
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' first objects.
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' first
|
||||
* objects.
|
||||
*/
|
||||
@Override
|
||||
public FluentIterable<TYPE> first(int count) {
|
||||
@ -106,6 +111,7 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the iteration. Is a terminating operation.
|
||||
*
|
||||
* @return an Optional containing the last object of this Iterable
|
||||
*/
|
||||
@Override
|
||||
@ -115,19 +121,22 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
}
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation.
|
||||
* This operation is memory intensive, because the contents of this Iterable
|
||||
* are collected into a List, when the next object is requested.
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation. This operation is
|
||||
* memory intensive, because the contents of this Iterable are collected into a List, when the
|
||||
* next object is requested.
|
||||
*
|
||||
* @param count defines the number of objects to return
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' last objects
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' last
|
||||
* objects
|
||||
*/
|
||||
@Override
|
||||
public FluentIterable<TYPE> last(int count) {return new LazyFluentIterable<TYPE>() {
|
||||
public FluentIterable<TYPE> last(int count) {
|
||||
return new LazyFluentIterable<TYPE>() {
|
||||
@Override
|
||||
public Iterator<TYPE> iterator() {
|
||||
return new DecoratingIterator<TYPE>(iterable.iterator()) {
|
||||
public int stopIndex;
|
||||
public int totalElementsCount;
|
||||
private int stopIndex;
|
||||
private int totalElementsCount;
|
||||
private List<TYPE> list;
|
||||
private int currentIndex = 0;
|
||||
|
||||
@ -165,6 +174,7 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Transforms this FluentIterable into a new one containing objects of the type NEW_TYPE.
|
||||
*
|
||||
* @param function a function that transforms an instance of TYPE into an instance of NEW_TYPE
|
||||
* @param <NEW_TYPE> the target type of the transformation
|
||||
* @return a new FluentIterable of the new type
|
||||
@ -176,6 +186,7 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
public Iterator<NEW_TYPE> iterator() {
|
||||
return new DecoratingIterator<NEW_TYPE>(null) {
|
||||
Iterator<TYPE> oldTypeIterator = iterable.iterator();
|
||||
|
||||
@Override
|
||||
public NEW_TYPE computeNext() {
|
||||
while (oldTypeIterator.hasNext()) {
|
||||
@ -191,6 +202,7 @@ public class LazyFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Collects all remaining objects of this iteration into a list.
|
||||
*
|
||||
* @return a list with all remaining objects of this iteration
|
||||
*/
|
||||
@Override
|
||||
|
@ -8,9 +8,9 @@ import java.util.function.Function;
|
||||
import java.util.function.Predicate;
|
||||
|
||||
/**
|
||||
* This is a simple implementation of the FluentIterable interface. It evaluates
|
||||
* all chained operations eagerly.
|
||||
* This implementation would be costly to be utilized in real applications.
|
||||
* This is a simple implementation of the FluentIterable interface. It evaluates all chained
|
||||
* operations eagerly. This implementation would be costly to be utilized in real applications.
|
||||
*
|
||||
* @param <TYPE> the type of the objects the iteration is about
|
||||
*/
|
||||
public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
@ -19,17 +19,19 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* This constructor creates a copy of a given iterable's contents.
|
||||
*
|
||||
* @param iterable the iterable this interface copies to work on.
|
||||
*/
|
||||
protected SimpleFluentIterable(Iterable<TYPE> iterable) {
|
||||
List<TYPE> copy = FluentIterable.copyToList(iterable);
|
||||
this.iterable = copy;
|
||||
this.iterable = iterable;
|
||||
}
|
||||
|
||||
/**
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy the predicate.
|
||||
* @param predicate the condition to test with for the filtering. If the test
|
||||
* is negative, the tested object is removed by the iterator.
|
||||
* Filters the contents of Iterable using the given predicate, leaving only the ones which satisfy
|
||||
* the predicate.
|
||||
*
|
||||
* @param predicate the condition to test with for the filtering. If the test is negative, the
|
||||
* tested object is removed by the iterator.
|
||||
* @return the same FluentIterable with a filtered collection
|
||||
*/
|
||||
@Override
|
||||
@ -46,6 +48,7 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation.
|
||||
*
|
||||
* @return an option of the first object of the Iterable
|
||||
*/
|
||||
@Override
|
||||
@ -56,8 +59,10 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation.
|
||||
*
|
||||
* @param count defines the number of objects to return
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' first objects.
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' first
|
||||
* objects.
|
||||
*/
|
||||
@Override
|
||||
public final FluentIterable<TYPE> first(int count) {
|
||||
@ -75,6 +80,7 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation.
|
||||
*
|
||||
* @return an option of the last object of the Iterable
|
||||
*/
|
||||
@Override
|
||||
@ -88,8 +94,10 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Can be used to collect objects from the Iterable. Is a terminating operation.
|
||||
*
|
||||
* @param count defines the number of objects to return
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' last objects
|
||||
* @return the same FluentIterable with a collection decimated to a maximum of 'count' last
|
||||
* objects
|
||||
*/
|
||||
@Override
|
||||
public final FluentIterable<TYPE> last(int count) {
|
||||
@ -109,6 +117,7 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Transforms this FluentIterable into a new one containing objects of the type NEW_TYPE.
|
||||
*
|
||||
* @param function a function that transforms an instance of TYPE into an instance of NEW_TYPE
|
||||
* @param <NEW_TYPE> the target type of the transformation
|
||||
* @return a new FluentIterable of the new type
|
||||
@ -125,6 +134,7 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Collects all remaining objects of this Iterable into a list.
|
||||
*
|
||||
* @return a list with all remaining objects of this Iterable
|
||||
*/
|
||||
@Override
|
||||
@ -139,6 +149,11 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
return new SimpleFluentIterable<>(iterable);
|
||||
}
|
||||
|
||||
public static final <TYPE> FluentIterable<TYPE> fromCopyOf(Iterable<TYPE> iterable) {
|
||||
List<TYPE> copy = FluentIterable.copyToList(iterable);
|
||||
return new SimpleFluentIterable<>(copy);
|
||||
}
|
||||
|
||||
@Override
|
||||
public Iterator<TYPE> iterator() {
|
||||
return iterable.iterator();
|
||||
@ -170,6 +185,7 @@ public class SimpleFluentIterable<TYPE> implements FluentIterable<TYPE> {
|
||||
|
||||
/**
|
||||
* Collects the remaining objects of the given iterator into a List.
|
||||
*
|
||||
* @return a new List with the remaining objects.
|
||||
*/
|
||||
public static <TYPE> List<TYPE> toList(Iterator<TYPE> iterator) {
|
||||
|
Loading…
x
Reference in New Issue
Block a user