Melle Lee

100% on Concurrency and Collections/Generics,
but only 72% and 70% on Flow Control and API contents.

I had only one month to prepare for the exam.

Thanks K&B for the excellent book.

Srinivas Bitla, I think you need to synchronize the inSync() method.

I only know that a nested class (static) does not hold an implicit reference "this" to its enclosing class, but a static method does.

Here is a program I tried. The interface can be declared private.

//: interfaces/RandomWords.java // Implementing an interface to conform to a method. package interfaces; public class PrivateInterface { private interface InnerInterface { void f(); } private class InnerClass1 implements InnerInterface { public void f() { System.out.println("From InnerClass1"); } } private class InnerClass2 implements InnerInterface { public void f() { System.out.println("From InnerClass2"); } } public static void main(String[] args) { PrivateInterface pi = new PrivateInterface(); pi.new InnerClass1().f(); pi.new InnerClass2().f(); } } /* Output: From InnerClass1 From InnerClass2 */
[ May 22, 2006: Message edited by: Melle Lee ]

A constructor cannot directly or indirectly invoke itself.

According to <<The Java Language Specification>> 8.2.1.4, if a class has a public superclass or superinterface, with the help of another public class in the same package that returns an instance of this class, instance of the class might be available at run time to codes outside its package, and its public methods, which implement or override the methods of its public superclass or superinterface, can be invoked through these instances.

I am going for SCJP 5.0 because it's the newest version and seems interesting. But I don't know whether Java 1.4 is more widely used.

A type variable for a generic class declaration use only the keyword "extends".

But the parameterized type can use both keywords "super" and "extends".

It's because the program
"throw new Level1Exception();"
before the second "try", so the second "try" is not reachable.

My answer:

B. True
Since setXY() is not synchronized, the following sequence is possible:
setX(1); // the first thread
setX(2); // the second thread
setY(1); // the first thread
check();
setY(2); // the second thread
[ April 16, 2006: Message edited by: Spring ]

I got compile error (x is possibly not initialized) for sample 2:

public class CrazyAssignment{
public static void main(String[] args){
System.out.println("Hello");
int k;
for (;true||(k=readint())>0 ; ) {}

int x;
for (boolean xF = true;xF || (x=readint())>0 ; ) {
System.out.println("x:"+x);
break;
}
}
static int readint(){return 1;}
}

I have checked the answers on my computer.
A4 is valid.