!1097 修复合成注解在并发环境无法保证正确缓存属性值的问题（#I8CLBJ）

Merge pull request !1097 from Createsequence/fix/I8CLBJ

hutool-core/src/test/java/cn/hutool/core/annotation/TestIssueI8CLBJ.java

@@ -0,0 +1,64 @@
+package cn.hutool.core.annotation;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.lang.annotation.Annotation;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author huangchengxing
+ */
+public class TestIssueI8CLBJ {
+
+	@Test
+	public void test() throws NoSuchFieldException {
+		Field field = Foo.class.getDeclaredField("name");
+		Assert.assertNotNull(field);
+		Annotation[] annotations = field.getDeclaredAnnotations();
+		Assert.assertTrue(annotations.length > 0);
+
+		TestAnnotation annotation = AnnotationUtil.getSynthesizedAnnotation(TestAnnotation.class, annotations);
+		List<Thread> threadList = new ArrayList<>();
+		for (int i = 0; i < 30; i++) {
+			Thread thread = new Thread(() -> {
+				try {
+					String valueFieldName = annotation.valueFieldName();
+					System.out.println("valueFieldName:" + valueFieldName);
+				} catch (Exception e) {
+					e.printStackTrace();
+				}
+			});
+			threadList.add(thread);
+			thread.start();
+		}
+
+		try {
+			for (Thread thread : threadList) {
+				thread.join();
+			}
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+
+	public static class Foo {
+		private Integer id;
+		@TestAnnotation("name")
+		private String name;
+	}
+
+	@Target(ElementType.FIELD)
+	@Retention(RetentionPolicy.RUNTIME)
+	private @interface TestAnnotation {
+		String value() default "";
+		@Alias("value")
+		String valueFieldName() default "";
+	}
+}