Formats messages according to very simple substitution rules. Substitutions
can be made 1, 2 or more arguments.
For example,
MessageFormatter.format("Hi {}.", "there")
will return the string "Hi there.".
The {} pair is called the
formatting anchor. It serves to designate
the location where arguments need to be substituted within the message
pattern.
In case your message contains the '{' or the '}' character, you do not have
to do anything special unless the '}' character immediately follows '{'. For
example,
MessageFormatter.format("Set {1,2,3} is not equal to {}.", "1,2");
will return the string "Set {1,2,3} is not equal to 1,2.".
If for whatever reason you need to place the string "{}" in the message
without its
formatting anchor meaning, then you need to escape the
'{' character with '\', that is the backslash character. Only the '{'
character should be escaped. There is no need to escape the '}' character.
For example,
MessageFormatter.format("Set \\{} is not equal to {}.", "1,2");
will return the string "Set {} is not equal to 1,2.".
The escaping behavior just described can be overridden by escaping the escape
character '\'. Calling
MessageFormatter.format("File name is C:\\\\{}.", "file.zip");
will return the string "File name is C:\file.zip".
The formatting conventions are different than those of
MessageFormat
which ships with the Java platform. This is justified by the fact that
SLF4J's implementation is 10 times faster than that of
MessageFormat.
This local performance difference is both measurable and significant in the
larger context of the complete logging processing chain.
See also
format(String, Object),
format(String, Object, Object) and
arrayFormat(String, Object[]) methods for more details.