--- old/src/java.base/share/classes/java/lang/String.java 2016-04-27 13:30:06.112679852 +0300 +++ new/src/java.base/share/classes/java/lang/String.java 2016-04-27 13:30:06.000680374 +0300 @@ -78,9 +78,10 @@ *

* The Java language provides special support for the string * concatenation operator ( + ), and for conversion of - * other objects to strings. String concatenation is implemented - * through the {@code StringBuilder}(or {@code StringBuffer}) - * class and its {@code append} method. + * other objects to strings. At the discretion of Java compiler, + * String concatenation may be implemented through any JDK API, e.g. + * the {@code StringBuilder} or the {@code java.lang.invoke.StringConcatFactory}, + * as long as it satisfies the requirements of the The Java Language Specification. * String conversions are implemented through the method * {@code toString}, defined by {@code Object} and * inherited by all classes in Java. For additional information on