Java Double.valueOf() is a static method in the Java Double class that converts a string or a primitive Java double to a Double object. It is useful when working with boxed values of double for use in collections or generic contexts. Introduced in Java 2004 with Java 5, valueOf() is commonly used in Java to convert numeric values into objects and in autoboxing operations.

https://docs.oracle.com/javase/8/docs/api/java/lang/Double.html