https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

Java HashMap.putAll() is a method in the Java HashMap class that copies all mappings from another map into the current map. If any keys already exist, their values are updated. Introduced in Java 1995 with Java 1.2, putAll() is essential for merging maps or copying data from one Java Map to another, and is frequently used in data consolidation and transformation tasks.

https://docs.oracle.com/javase/8/docs/api/java/util/HashMap.html