Java EE Applications: Calling a JSF page from a non-JSF page

Lab 6 replaces the CustomerController servlet with the ustomerDetails.xhtml JSF page.
Existing JSP pages need to be adapted to call the JSF page. Here's how you call a JSF page from a JSP or plain HTML page and pass a parameter to it.

1. Change the AllCustomers.jsp page to call the JSF page.
• Existing call to the servlet

 <a href="CustomerController?customerIdentity=<%= customers[i].getId()%>&submit=Get Customer">

• New call to the JSF page

<a href="CustomerDetails.xhtml?customerIdentity=<%= customers[i].getId()%>">  

• Change the JSF backing bean to receive parameters and call code when it is created by a GET request.
1. Receive a GET parameter in an attribute

@ManagedBean(name="customerDetails")
@RequestScoped
public class CustomerManagedBean {

   @ManagedProperty("#{param.customerIdentity}")
   private String customerId = "";
   ...
}

2. Call a method when the bean is created. The method looks up data using the value stored in the attribute in the previous step.

@PostConstruct
public void initCustomer() {
  if (customerId != null && customerId.length()!= 0){
    retrieveCustomer();
  }
}

Expression Language 3.0 is in public review

The Expression Language (EL) is widely used in JSP and JSF. With version 3 the EL now becomes an independent specification. The EL v3 (JSR 314) is in public review until the end of July. It will be released in sync with Java EE 7 (Update: EL 3.0 was released in may 2013). New features include:

•  As an independent specification, EL now comes with a standalone API, allowing usage outside a web container.
  
• You can write your own ELProcessor. The source code is available, but I wish they had put the javadoc for  browsing at the project site as well.
• Java 8 stuff
• Lambda expressions
• Collection literals follow proposed Java 8 syntax
• List: [1, "two", 3.0]
• Set: {1, 2, 3}
• Map: {"one":1, "two":2, "three":3}
• Collection streaming
• Assignment operator (=) for changing values:
• ${customer.name = 'Jan'}
• String concatenation: + or cat operator
• ${‘Welcome ‘ += customer.name += ‘ to our site’}.
• Support for static references using the T construct (Type). 
• By default only java.* and javax.* packages are available, but you can modify this using the EL API.
  
• ${T(java.util.Calendar).APRIL}
• ${T(java.util.Calendar).getInstance()}
•  You can call constructors as a static method without a name. To call the default Calendar constructor:
  
• ${T(java.util.Calendar).()}
• For java.lang you can use the class without using the T construct
• ${Boolean.TRUE}