[slf4j-user] separation of format and data

[Jiri Pejchal]

"Ed Bras" <zooi at debrasjes.com> writes:

> I like to have more control over the output format and data input by
> separating these things.
> How can I do this?
>
> I would like to do something like this:
> Logger.debug("some debug data", "Member", this.member, "Address",
> this.address);
>
> Then the formatter would output something like this:
> Some debug data.
> Member= [Member at dfsdf,  id=2434, ....]
> Address= [Adress at dafa, street=bla, postalCode=34324234, ...]
>
> The text between [] is the toString output.
> I use this in other parts, like in my asserts and toString logging since a
> few years now, and like it: development friendly, that is: easy usage in
> code and readably output (especially with complex data structures this is a
> requirement).
>
> I could do the above through a static Utils method, something like this:
> UtilsLogger.debug(logger, "some debug data", "Member", this.member,
> "Address", this.address);
> And then the Utils method will construct the complete log statement with the
> {} in it.
> But might it not an idea to make this part of the Logger Facade?.. Or is
> there a way to extend SLF4j to add this myself?
>
> Please some advice?
> Ed

I don't know if I understand you correctly, by I usually use something like:

import static com.google.common.base.Objects.toStringHelper;

public class User {
    private Long id;
    private String firstName;
    private String lastName;

    @Override
    public String toString() {
        return toStringHelper(this).
                add("id", id).
                add("firstName", firstName).
                add("lastName", lastName).
                toString();
    }
}




userService.create(user);
logger.info("Created {}", user);

And the result is:
22:50:51.116 [http-8084-1] INFO  cz.asterix.beans.DataInitBean (DataInitBean.java:71) Created User{id=1, firstName=Jan, lastName=Novak}



Jiri Pejchal