Yes, String.format was introduced in Java5, along with Scanner and Formatter; if I remember correctly, String.format uses Formatter.
The % tags (which date back to C in the early 1970s, maybe even farther back
look for "the March of Progress") are much easier to use than the DecimalFormat classes which appear to be called by MessageFormat. Most of us who remember DecimalFormat were only too pleased to be able to use % tags. For details of the % tags, look under Formatter in the API documentation.