From 32d0b65744d8969c5691af829bfbccca141e5339 Mon Sep 17 00:00:00 2001
From: huangchengxing <841396397@qq.com>
Date: Tue, 5 Jul 2022 13:39:56 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E6=B3=A8=E8=A7=A3=E5=B1=9E?=
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---
 ...nthesizedAnnotationAttributeProcessor.java | 49 +++++++++++++++++++
 ...nthesizedAnnotationAttributeProcessor.java | 24 +++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 hutool-core/src/main/java/cn/hutool/core/annotation/CacheableSynthesizedAnnotationAttributeProcessor.java
 create mode 100644 hutool-core/src/main/java/cn/hutool/core/annotation/SynthesizedAnnotationAttributeProcessor.java

diff --git a/hutool-core/src/main/java/cn/hutool/core/annotation/CacheableSynthesizedAnnotationAttributeProcessor.java b/hutool-core/src/main/java/cn/hutool/core/annotation/CacheableSynthesizedAnnotationAttributeProcessor.java
new file mode 100644
index 000000000..3329bc2f1
--- /dev/null
+++ b/hutool-core/src/main/java/cn/hutool/core/annotation/CacheableSynthesizedAnnotationAttributeProcessor.java
@@ -0,0 +1,49 @@
+package cn.hutool.core.annotation;
+
+import cn.hutool.core.map.multi.RowKeyTable;
+import cn.hutool.core.map.multi.Table;
+import cn.hutool.core.util.ObjectUtil;
+
+import java.util.Collection;
+import java.util.Comparator;
+
+/**
+ * 带缓存功能的{@link SynthesizedAnnotationAttributeProcessor}实现，
+ * 构建时需要传入比较器，获取属性值时将根据比较器对合成注解进行排序，
+ * 然后选择具有所需属性的，排序最靠前的注解用于获取属性值
+ *
+ * @param <A> 合成注解类型
+ * @author huangchengxing
+ */
+public class CacheableSynthesizedAnnotationAttributeProcessor<A extends SynthesizedAnnotation<?>> implements
+	SynthesizedAnnotationAttributeProcessor<A> {
+
+	private final Table<String, Class<?>, Object> valueCaches = new RowKeyTable<>();
+	private final Comparator<A> annotationComparator;
+
+	/**
+	 * 创建一个带缓存的注解值选择器
+	 *
+	 * @param annotationComparator 注解比较器，排序更靠前的注解将被优先用于获取值
+	 */
+	public CacheableSynthesizedAnnotationAttributeProcessor(Comparator<A> annotationComparator) {
+		this.annotationComparator = annotationComparator;
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public <T> T getAttributeValue(String attributeName, Class<T> attributeType, Collection<A> synthesizedAnnotations) {
+		Object value = valueCaches.get(attributeName, attributeType);
+		// 此处理论上不可能出现缓存值为nul的情况
+		if (ObjectUtil.isNotNull(value)) {
+			return (T)value;
+		}
+		value = synthesizedAnnotations.stream()
+			.filter(ma -> ma.hasAttribute(attributeName, attributeType))
+			.min(annotationComparator)
+			.map(ma -> ma.getAttribute(attributeName))
+			.orElse(null);
+		valueCaches.put(attributeName, attributeType, value);
+		return (T)value;
+	}
+}
diff --git a/hutool-core/src/main/java/cn/hutool/core/annotation/SynthesizedAnnotationAttributeProcessor.java b/hutool-core/src/main/java/cn/hutool/core/annotation/SynthesizedAnnotationAttributeProcessor.java
new file mode 100644
index 000000000..022afb8ce
--- /dev/null
+++ b/hutool-core/src/main/java/cn/hutool/core/annotation/SynthesizedAnnotationAttributeProcessor.java
@@ -0,0 +1,24 @@
+package cn.hutool.core.annotation;
+
+import java.util.Collection;
+
+/**
+ * 合成注解属性选择器。用于中合成注解中从指定类型的注解里获取到对应的属性值
+ *
+ * @author huangchengxing
+ */
+@FunctionalInterface
+public interface SynthesizedAnnotationAttributeProcessor<A extends SynthesizedAnnotation<?>> {
+
+	/**
+	 * 从一批被合成注解中，获取指定名称与类型的属性值
+	 *
+	 * @param attributeName 属性名称
+	 * @param attributeType 属性类型
+	 * @param synthesizedAnnotations 被合成的注解
+	 * @param <T> 属性类型
+	 * @return 属性值
+	 */
+	<T> T getAttributeValue(String attributeName, Class<T> attributeType, Collection<A> synthesizedAnnotations);
+
+}