Merge pull request #27604 from Xjzon

* pr/27604:
  Polish "Add support for custom expression parsing"
  Add support for custom expression parsing

Closes gh-27604

spring-context/src/main/java/org/springframework/context/expression/CachedExpressionEvaluator.java

@@ -75,7 +75,7 @@ public abstract class CachedExpressionEvaluator {
 
 	/**
 	 * Return the {@link Expression} for the specified SpEL value
-	 * <p>Parse the expression if it hasn't been already.
+	 * <p>{@link #parseExpression(String) Parse the expression} if it hasn't been already.
 	 * @param cache the cache to use
 	 * @param elementKey the element on which the expression is defined
 	 * @param expression the expression to parse
@@ -86,12 +86,21 @@ public abstract class CachedExpressionEvaluator {
 		ExpressionKey expressionKey = createKey(elementKey, expression);
 		Expression expr = cache.get(expressionKey);
 		if (expr == null) {
-			expr = getParser().parseExpression(expression);
+			expr = parseExpression(expression);
 			cache.put(expressionKey, expr);
 		}
 		return expr;
 	}
 
+	/**
+	 * Parse the specified {@code expression}.
+	 * @param expression the expression to parse
+	 * @since 5.3.13
+	 */
+	protected Expression parseExpression(String expression) {
+		return getParser().parseExpression(expression);
+	}
+
 	private ExpressionKey createKey(AnnotatedElementKey elementKey, String expression) {
 		return new ExpressionKey(elementKey, expression);
 	}

spring-context/src/test/java/org/springframework/context/expression/CachedExpressionEvaluatorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.