Friday Java Quiz: What Does -source 1.4 Really Mean?

Today's quiz has to do with the -source and -target command line switches of the javac command. We are all familiar with these switches.

But do we really know how they work?

Suppose I have just built a new Debian 4.0 box, and installed Sun Java 5 on it. There are no other versions of Java installed on the box. Without actually invoking the compiler, answer the following question.

Will the following Foo.java:

public class Foo {
  public static void main(String[] args) {
    StringBuilder sb = new StringBuilder();
    sb.append("Hello, world.\n");
    System.out.println(sb.toString());
  }
}

compile successfully with the following command line:

javac -source 1.4 Foo.java

?

What about the following command line:

javac -source 1.4 -target 1.4 Foo.java

?

Explain why.

[Update] I should have mentioned that this is a two part question. And here is the second part. Answer the same questions for this class:

public class Bar {
  public static void main(String[] args) {
    System.out.printf("Hello, world.");
  }
}