Keerthi P

I think I was able explain this myself.

Consider the following code:

List<Sparrow> sparrows = new ArrayList<>(); List<? extends Bird> birds = sparrows;  // Because List<Sparrow> is a subtype of List<? extends Bird>, you can assign sparrows to birds. birds.add(new Bird());  // COMPILE ERROR - You cannot add a Bird to a list of sparrows. The compiler will try to prevent this from happening.

Page #120 (1Z0-809)
class Sparrow extends Bird {} class Bird {}
List<? extends Bird> birds = new ArrayList<Bird>(); birds.add(new Sparrow());    // line #6 DOES NOT COMPILE birds.add(new Bird());          // line #7 DOES NOT COMPILE

The authors write

List<? extends Bird> could be List<Bird> or List<Sparrow>. Line #7 doesn't compile because we can't add a Sparrow to List<Bird>

The above underlined is factually incorrect. Sparrow can be added to List<Bird>. Or atleast it is not convincingly explained why compilation fails. Could some help me understand why Line #6 not compile?

Pg 308, while the book states that the optional error_message is a String
assert boolean_expression: error_message

...the Java documentation states that it is an expression that has a value

assert Expression1 : Expression2 ;

where:
Expression1 is a boolean expression.
Expression2 is an expression that has a value. (It cannot be an invocation of a method that is declared void.)

Particularly the below quote from: https://docs.oracle.com/javase/7/docs/technotes/guides/language/assert.html

The system passes the value of Expression2 to the appropriate AssertionError constructor, which uses the string representation of the value as the error's detail message.

Expression2 is more "wider and broad" than String and I believe this deserves to be noted (and perhaps added to errata).

The following is a valid assert statement and compiles successfully:
int i = 0; assert i > 0: i

Locale.setDefault(new Locale("hi")); ResourceBundle.getBundle("Zoo", new Locale("en"))

Referring to page #264 on Jeanne's book, i'm a bit confused with the order mentioned. Isn't the following the right order in which the lookup will be made?

1. Zoo_en.java
2. Zoo_en.properties

3. Zoo_hi.java
4. Zoo_hi.properties

5. Zoo.java
6. Zoo.properties

public interface Driveable {   static boolean hasWheels() {       return true;   } }
public class Car implements Driveable {   public boolean canMove() {        //return this.hasWheels(); // <-- Compilation error        return Driveable.hasWheels(); // Compiles   } }
A class cannot access the implemented interface's static method using 'this' and should use the type name to get to the method. This makes perfect sense to me - The static method is not bound to an instance and therefore 'this' has no meaning in this case (and is also not inherited to be able to reach via 'this' from the class).

But I'm baffled why did the following compile:
public interface Driveable {   static boolean hasWheels = true; }

public class Car implements Driveable {   public boolean canMove() {        return this.hasWheels; // <-- Compiles! How come the compiler is able to reach static variable through 'this'?   } }
Why is the compiler seeing the interface's static variable differently? Appreciate your replies.

Thank you!

Its been a while since gave Exam #1 (1Z0-808). Now, I'm planning to start preparing for Exam #2 (1Z0-809). Should I read the book for Exam #1 to tackle Exam #2?

It appears the Kindle version of Jeanne's book (link below) is pretty old. I hear the latest reprint of the book contains most of the errata addressed in the print. Where can I buy an ebook (any format works for me) version of the latest reprint?

https://www.amazon.in/OCA-Certified-Associate-Programmer-1Z0-808-ebook/dp/B00R04DF3I

I have posted a simplified case of the issue here https://issues.apache.org/jira/browse/MYFACES-2392 and here
https://facelets.dev.java.net/issues/show_bug.cgi?id=358

If anyone has any clue, please advise.

List<UIComponent> children = getChildren(); // loop thru children

is same as

List<UIComponent> childrenList = getChildren(); Object[] childobjs = childrenList.toArray(); // loop thru childobjs

You may want to add enctype="multipart/form-data" to your form tag. The standard h:form supports this attribute. Typical usage is as below:
<h:form enctype="multipart/form-data"> <!-- other form elements --> </h:form>
You seem to be using ice faces. Check the documentation of ice:form tag.

I have a custom JSF component that renders navigation links. The following is a typical usage of the component:
<custom:navigationBar id="navbar" spacing="2" actionListener="#{testBean.navigationLinkClicked}" immediate="true" binding="#{testBean.navigationBar}"> <custom:navigationLink id="primaryData" value="Primary Data"/> <custom:navigationLink id="principals" value="Principals" active="true"/> <custom:navigationLink id="administrators" value="Administrators"/> <custom:navigationLink id="custodians" value="Custodians"/> <custom:navigationLink id="accountingFirms" value="Accounting Firms" clickable="false"/> <custom:navigationLink id="lawFirms" value="Law Firms" clickable="false"/> <custom:navigationLink id="billing" value="Billing" clickable="false"/> </custom:navigationBar>

And, the rendered content will appear as following, similar to the navigation links at the top of this page:

Primary Data | Principals | Administrators | Custodiams | Accounting Firms | Law Firms | Billing

As you notice, the navigationBar component is bounded to #{testBean.navigationBar} which is defined as below in the Backing bean:
public class TestBean { private HtmlNavigationBar navigationBar; .... public String formSubmitted() { HtmlNavigationLink link = new HtmlNavigationLink(); link.setId("link"); link.setValue("New link"); navigationBar.getChildren().add(link) return null; }

The backing bean has an action method formSubmitted() that adds a child (HtmlNavigationLink) component to the parent (HtmlNavigationBar) dynamically. I thought that this newly added child would be the last child (as it is added to end of the children list). But, when the navigationBar renders its children, the HtmlNavigationLink 'New link' appears as the first child causing the content rendered as below:

New Link | Primary Data | Principals | Administrators | Custodiams | Accounting Firms | Law Firms | Billing

The following is the encodeChildren() method of HtmlNavigationBar
@Override public void encodeChildren(FacesContext context) throws IOException { ResponseWriter writer = context.getResponseWriter(); List<UIComponent> children = getChildren(); int count = children.size(); for (int i = 0; i < count; i++) { UIComponent child = children.get(i); // -- why does 'New link' appear at index == 0? if (child instanceof HtmlNavigationLink) { child.encodeAll(context); } } }
As noted in the comment above, while the link was added to the end of the list in the action method, it appears at index position 0 as the first child? Why is it so?

It (the Business Delegate) is passed to a remote facade.

You may want to reconsider this design.

Why not? Do not confuse JMS with MDBs.

No you don't have to. You can still take SCBCD.