Merge branch 'master' of https://github.com/spring-projects/spring-framework into read_yuyang

* 'master' of https://github.com/spring-projects/spring-framework:
  Include Objenesis NOTICE file contents in binary distributions
  Fix Checkstyle violation
  Update copyright date
  Simplify getParsedSql() method in NamedParameterJdbcTemplate
  Document supported characters for identifiers in SpEL expressions

Author: yuyang

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterJdbcTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -430,12 +430,7 @@ protected ParsedSql getParsedSql(String sql) {
 			return NamedParameterUtils.parseSqlStatement(sql);
 		}
 		synchronized (this.parsedSqlCache) {
-			ParsedSql parsedSql = this.parsedSqlCache.get(sql);
-			if (parsedSql == null) {
-				parsedSql = NamedParameterUtils.parseSqlStatement(sql);
-				this.parsedSqlCache.put(sql, parsedSql);
-			}
-			return parsedSql;
+			return this.parsedSqlCache.computeIfAbsent(sql, NamedParameterUtils::parseSqlStatement);
 		}
 	}
 

src/docs/asciidoc/core/core-expressions.adoc

@@ -1382,8 +1382,20 @@ example shows how to use the `new` operator to invoke constructors:
 === Variables
 
 You can reference variables in the expression by using the `#variableName` syntax. Variables
-are set by using the `setVariable` method on `EvaluationContext` implementations. The
-following example shows how to use variables:
+are set by using the `setVariable` method on `EvaluationContext` implementations.
+
+[NOTE]
+====
+Valid variable names must be composed of one or more of the following supported
+characters.
+
+* letters: `A` to `Z` and `a` to `z`
+* digits: `0` to `9`
+* underscore: `_`
+* dollar sign: `$`
+====
+
+The following example shows how to use variables.
 
 [source,java,indent=0,subs="verbatim,quotes",role="primary"]
 .Java

src/docs/dist/license.txt

@@ -261,6 +261,13 @@ Per the LICENSE file in the Objenesis ZIP distribution downloaded from
 http://objenesis.org/download.html, Objenesis 3.1 is licensed under the
 Apache License, version 2.0, the text of which is included above.
 
+Per the NOTICE file in the Objenesis ZIP distribution downloaded from
+http://objenesis.org/download.html and corresponding to section 4d of the
+Apache License, Version 2.0, in this case for Objenesis:
+
+Objenesis
+Copyright 2006-2019 Joe Walnes, Henri Tremblay, Leonardo Mesquita
+
 
 ===============================================================================