Errata

Vulnerability in add() causes exception in the [admittedly extreme] case where the code executes:

myIntList.clear(); // removes all entries, so size now = 0
myIntList.trim(); // sets capacity = size = 0
myIntList.add(49); // or any valid int doubles capacity 0 to yield 0, then attempts to insert index 1 causing exception.

Suggested correction (could move check to setCapacity() if desired):

// Append a new value to the list, reallocating if necessary
public void add(int value) {
if (size == data. length) setCapacity((0 == data.length) ? DEFAULT_CAPACITY : size*2); // realloc if necessary
data[ size++] = value; // add value to list
}

On class PlayerPiano in book Java Examples in a Nutshell, 3rd Edition, on Java and Sound, Part 2
I ran into this code:


static final int[ ] offsets = { // add these amounts to the base value
// A B C D E F G
-4, -2, 0, 1, 3, 5, 7
};



When played the example string "A B C D E F G +A s/32 D E C D E C /1-->>CEG" plays actually C D E F G H A B, and then in the end plays a EGB chord (E-minor).
The right code should be:

static final int[ ] offsets = { // add these amounts to the base value
// A B C D E F G
-3, -1, 0, 2, 4, 5, 7
};


because the offsets are on semi-tones, and these are the correct musical offsets. Namely, note A is 3 semitones lower than C, note B is one semitone lower than C and
so forth.

1) http://localhost:8080/je3/HelloNet

should read:

http://localhost:8080/je3/Hello

2) It then follows that

http://localhost:8080/je3/HelloNet?username=David

should read

http://localhost:8080/je3/Hello?username=David

-This is based of the web.xml included with these examples.