Consistent support for SpEL next to placeholders in annotation attributes

Issue: SPR-13625

spring-beans/src/main/java/org/springframework/beans/factory/config/EmbeddedValueResolver.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2002-2016 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.beans.factory.config;
+
+import org.springframework.util.StringValueResolver;
+
+/**
+ * {@link StringValueResolver} adapter for resolving placeholders and
+ * expressions against a {@link ConfigurableBeanFactory}.
+ *
+ * <p>Note that this adapter resolves expressions as well, in contrast
+ * to the {@link ConfigurableBeanFactory#resolveEmbeddedValue} method.
+ * The {@link BeanExpressionContext} used is for the plain bean factory,
+ * with no scope specified for any contextual objects to access.
+ *
+ * @author Juergen Hoeller
+ * @since 4.3
+ * @see ConfigurableBeanFactory#resolveEmbeddedValue(String)
+ * @see ConfigurableBeanFactory#getBeanExpressionResolver()
+ * @see BeanExpressionContext
+ */
+public class EmbeddedValueResolver implements StringValueResolver {
+
+	private final BeanExpressionContext exprContext;
+
+	private final BeanExpressionResolver exprResolver;
+
+
+	public EmbeddedValueResolver(ConfigurableBeanFactory beanFactory) {
+		this.exprContext = new BeanExpressionContext(beanFactory, null);
+		this.exprResolver = beanFactory.getBeanExpressionResolver();
+	}
+
+
+	@Override
+	public String resolveStringValue(String strVal) {
+		String value = this.exprContext.getBeanFactory().resolveEmbeddedValue(strVal);
+		if (this.exprResolver != null && value != null) {
+			Object evaluated = this.exprResolver.evaluate(value, this.exprContext);
+			value = (evaluated != null ? evaluated.toString() : null);
+		}
+		return value;
+	}
+
+}