spring-projects#45 - Introduced PluginRegistry.of(…) factory methods.

The introduced methods mostly mimic the ones available on OrderAwarePluginRegistry except the one that's implying a certain order in the first place. Also introduced ….of(…) factory methods on OrderAwarePluginRegistry and deprecated the ….create(…) ones.

Author: odrotbohm

core/src/main/java/org/springframework/plugin/core/OrderAwarePluginRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2012 the original author or authors.
+ * Copyright 2008-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 package org.springframework.plugin.core;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
@@ -37,12 +38,12 @@ public class OrderAwarePluginRegistry<T extends Plugin<S>, S> extends SimplePlug
  * Comparator regarding {@link org.springframework.core.Ordered} interface or
  * {@link org.springframework.core.annotation.Order} annotation.
  */
-private static final Comparator<Object> DEFAULT_COMPARATOR = new AnnotationAwareOrderComparator();
+static final Comparator<Object> DEFAULT_COMPARATOR = new AnnotationAwareOrderComparator();
 
 /**
  * Comparator reverting the {@value #DEFAULT_COMPARATOR}.
  */
-private static final Comparator<Object> DEFAULT_REVERSE_COMPARATOR = DEFAULT_COMPARATOR.reversed();
+static final Comparator<Object> DEFAULT_REVERSE_COMPARATOR = DEFAULT_COMPARATOR.reversed();
 
 private final Comparator<? super T> comparator;
 
@@ -67,8 +68,9 @@ protected OrderAwarePluginRegistry(List<? extends T> plugins, Comparator<? super
  * Creates a new {@link OrderAwarePluginRegistry} using the {@code #DEFAULT_COMPARATOR}.
  * 
  * @return
+ * @since 2.0
  */
-public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create() {
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> empty() {
 return create(Collections.emptyList());
 }
 
@@ -78,8 +80,9 @@ public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create() {
  * 
  * @param comparator must not be {@literal null}.
  * @return
+ * @since 2.0
  */
-public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(Comparator<? super T> comparator) {
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> of(Comparator<? super T> comparator) {
 
 Assert.notNull(comparator, "Comparator must not be null!");
 
@@ -88,11 +91,23 @@ public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(Com
 
 /**
  * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
- * 
  * @param plugins must not be {@literal null}.
  * @return
+ * @since 2.0
  */
-public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(List<? extends T> plugins) {
+@SafeVarargs
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> of(T... plugins) {
+return create(Arrays.asList(plugins), DEFAULT_COMPARATOR);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @since 2.0
+ */
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> of(List<? extends T> plugins) {
 return create(plugins, DEFAULT_COMPARATOR);
 }
 
@@ -102,8 +117,9 @@ public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(Lis
  * 
  * @param plugins must not be {@literal null}.
  * @return
+ * @since 2.0
  */
-public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> createReverse(List<? extends T> plugins) {
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> ofReverse(List<? extends T> plugins) {
 return create(plugins, DEFAULT_REVERSE_COMPARATOR);
 }
 
@@ -112,8 +128,9 @@ public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> createReve
  * 
  * @param plugins
  * @return
+ * @since 2.0
  */
-public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(List<? extends T> plugins,
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> of(List<? extends T> plugins,
 Comparator<? super T> comparator) {
 
 Assert.notNull(plugins, "Plugins must not be null!");
@@ -122,7 +139,73 @@ public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(Lis
 return new OrderAwarePluginRegistry<>(plugins, comparator);
 }
 
-/* 
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} using the {@code #DEFAULT_COMPARATOR}.
+ *
+ * @return
+ * @deprecated since 2.0, for removal in 2.1. Prefer {@link PluginRegistry#empty()}.
+ */
+@Deprecated
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create() {
+return empty();
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} using the given {@link Comparator} for ordering contained
+ * {@link Plugin}s.
+ *
+ * @param comparator must not be {@literal null}.
+ * @return
+ * @deprecated since 2.0, for removal in 2.1. Prefer {@link PluginRegistry#of(Comparator)}.
+ */
+@Deprecated
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(Comparator<? super T> comparator) {
+
+Assert.notNull(comparator, "Comparator must not be null!");
+
+return of(Collections.emptyList(), comparator);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @deprecated since 2.0, for removal in 2.1. Prefer {@link PluginRegistry#of(List)}.
+ */
+@Deprecated
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(List<? extends T> plugins) {
+return of(plugins, DEFAULT_COMPARATOR);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given {@link Plugin}s and the order of the {@link Plugin}s
+ * reverted.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @deprecated since 2.0, for removal in 2.1. Prefer {@link OrderAwarePluginRegistry#ofReverse(List)}
+ */
+@Deprecated
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> createReverse(List<? extends T> plugins) {
+return of(plugins, DEFAULT_REVERSE_COMPARATOR);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @deprecated since 2.0, for removal in 2.1. Prefer {@link PluginRegistry#of(List, Comparator)}.
+ */
+@Deprecated
+public static <S, T extends Plugin<S>> OrderAwarePluginRegistry<T, S> create(List<? extends T> plugins,
+Comparator<? super T> comparator) {
+
+return of(plugins, comparator);
+}
+
+/*
  * (non-Javadoc)
  * @see org.springframework.plugin.core.PluginRegistrySupport#initialize(java.util.List)
  */

core/src/main/java/org/springframework/plugin/core/PluginRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2017 the original author or authors.
+ * Copyright 2008-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,10 +15,15 @@
  */
 package org.springframework.plugin.core;
 
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
 import java.util.function.Supplier;
 
+import org.springframework.util.Assert;
+
 /**
  * Registry for {@link Plugin}s. Allows sophisticated typesafe access to implementations of interfaces extending {link
  * Plugin}.
@@ -29,6 +34,69 @@
  */
 public interface PluginRegistry<T extends Plugin<S>, S> extends Iterable<T> {
 
+/**
+ * Creates a new {@link PluginRegistry} using the {@code #DEFAULT_COMPARATOR}.
+ *
+ * @return
+ * @since 2.0
+ */
+public static <S, T extends Plugin<S>> PluginRegistry<T, S> empty() {
+return of(Collections.emptyList());
+}
+
+/**
+ * Creates a new {@link PluginRegistry} using the given {@link Comparator} for ordering contained {@link Plugin}s.
+ *
+ * @param comparator must not be {@literal null}.
+ * @return
+ * @since 2.0
+ */
+public static <S, T extends Plugin<S>> PluginRegistry<T, S> of(Comparator<? super T> comparator) {
+
+Assert.notNull(comparator, "Comparator must not be null!");
+
+return of(Collections.emptyList(), comparator);
+}
+
+/**
+ * Creates a new {@link PluginRegistry} with the given plugins.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @since 2.0
+ */
+@SafeVarargs
+public static <S, T extends Plugin<S>> PluginRegistry<T, S> of(T... plugins) {
+return of(Arrays.asList(plugins), OrderAwarePluginRegistry.DEFAULT_COMPARATOR);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
+ *
+ * @param plugins must not be {@literal null}.
+ * @return
+ * @since 2.0
+ */
+public static <S, T extends Plugin<S>> PluginRegistry<T, S> of(List<? extends T> plugins) {
+return of(plugins, OrderAwarePluginRegistry.DEFAULT_COMPARATOR);
+}
+
+/**
+ * Creates a new {@link OrderAwarePluginRegistry} with the given plugins.
+ *
+ * @param plugins
+ * @return
+ * @since 2.0
+ */
+public static <S, T extends Plugin<S>> PluginRegistry<T, S> of(List<? extends T> plugins,
+Comparator<? super T> comparator) {
+
+Assert.notNull(plugins, "Plugins must not be null!");
+Assert.notNull(comparator, "Comparator must not be null!");
+
+return OrderAwarePluginRegistry.of(plugins, comparator);
+}
+
 /**
  * Returns the first {@link Plugin} found for the given delimiter. Thus, further configured {@link Plugin}s are
  * ignored.

core/src/test/java/org/springframework/plugin/core/OrderAwarePluginRegistryUnitTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2017 the original author or authors.
+ * Copyright 2008-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,9 +17,8 @@
 
 import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
-import static org.springframework.plugin.core.OrderAwarePluginRegistry.*;
+import static org.springframework.plugin.core.PluginRegistry.*;
 
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
@@ -54,29 +53,14 @@ public void setUp() {
 @Test
 public void honorsOrderOnAddPlugins() throws Exception {
 
-PluginRegistry<TestPlugin, String> registry = OrderAwarePluginRegistry
-.create(Arrays.asList(firstPlugin, secondPlugin));
+PluginRegistry<TestPlugin, String> registry = of(firstPlugin, secondPlugin);
 assertOrder(registry, secondPlugin, firstPlugin);
 }
 
-private void assertOrder(PluginRegistry<TestPlugin, String> registry, TestPlugin... plugins) {
-
-List<TestPlugin> result = registry.getPluginsFor(null);
-
-assertThat(plugins.length, is(result.size()));
-
-for (int i = 0; i < plugins.length; i++) {
-assertThat(result.get(i), is(plugins[i]));
-}
-
-assertThat(registry.getPluginFor(null), is(Optional.of(plugins[0])));
-}
-
 @Test
 public void createsRevertedRegistryCorrectly() throws Exception {
 
-OrderAwarePluginRegistry<TestPlugin, String> registry = OrderAwarePluginRegistry
-.create(Arrays.asList(firstPlugin, secondPlugin));
+OrderAwarePluginRegistry<TestPlugin, String> registry = OrderAwarePluginRegistry.of(firstPlugin, secondPlugin);
 PluginRegistry<TestPlugin, String> reverse = registry.reverse();
 
 assertOrder(registry, secondPlugin, firstPlugin);
@@ -92,25 +76,41 @@ public void considersJdkProxiedOrderedImplementation() {
 ThirdImplementation plugin = new ThirdImplementation();
 TestPlugin thirdPlugin = (TestPlugin) new ProxyFactory(plugin).getProxy();
 
-OrderAwarePluginRegistry<TestPlugin, String> registry = create(
-Arrays.asList(firstPlugin, secondPlugin, thirdPlugin));
+OrderAwarePluginRegistry<TestPlugin, String> registry = OrderAwarePluginRegistry.of(firstPlugin, secondPlugin,
+thirdPlugin);
+
 assertOrder(registry, secondPlugin, thirdPlugin, firstPlugin);
 assertOrder(registry.reverse(), firstPlugin, thirdPlugin, secondPlugin);
 }
 
 @Test
 public void defaultSetupUsesDefaultComparator() {
-assertDefaultComparator(OrderAwarePluginRegistry.<String, TestPlugin> create());
+assertDefaultComparator(OrderAwarePluginRegistry.empty());
 }
 
 @Test
 public void defaultSetupUsesDefaultReverseComparator() {
+
 OrderAwarePluginRegistry<Plugin<Object>, Object> registry = OrderAwarePluginRegistry
-.createReverse(Collections.<Plugin<Object>> emptyList());
+.ofReverse(Collections.emptyList());
 Object field = ReflectionTestUtils.getField(registry, "comparator");
+
 assertThat(field, is(ReflectionTestUtils.getField(registry, "DEFAULT_REVERSE_COMPARATOR")));
 }
 
+private static void assertOrder(PluginRegistry<TestPlugin, String> registry, TestPlugin... plugins) {
+
+List<TestPlugin> result = registry.getPluginsFor(null);
+
+assertThat(plugins.length, is(result.size()));
+
+for (int i = 0; i < plugins.length; i++) {
+assertThat(result.get(i), is(plugins[i]));
+}
+
+assertThat(registry.getPluginFor(null), is(Optional.of(plugins[0])));
+}
+
 private static void assertDefaultComparator(OrderAwarePluginRegistry<?, ?> registry) {
 
 Object field = ReflectionTestUtils.getField(registry, "comparator");