What are helper objects in java?

Question

I come across few of the times called helper objects... can anybody elaborate what are those helper objects and why do we need them?

Answer 1

These are objects that "sit to the side" of the main body of code, and do some of the work for the object. They "help" the object to do it's job.

As an example, many people have a Closer helper object. This will take various closeable objects, for example, java.sql.Statement, java.sql.Connection, etc and will close the object, and ignore any errors that come out of it. This tends to be because if you get an error closing an object, there is not much you can do about it anyway, so people just ignore it.

Rather than having this boilerplate:

try {
  connection.close();
} catch (SQLException e) {
  // just ignore… what can you do when you can't close the connection?
   log.warn("couldn't close connection", e);
}

scattered around the codebase, they simply call:

Closer.close(connection);

instead. For example, look at guava closeQuietly.