Monday, February 23, 2009

Sun Certified Web Component Developer for the Java Platform, Enterprise Edition 5 (CX-310-083)

  • Delivered at: Authorized Worldwide Prometric Testing Centers
  • Prerequisites: Sun Certified Programmer for the Java Platform (any edition)
  • Exam type: Multiple Choice and Drag and Drop
  • Number of questions: 69
  • Pass score: 70% (49 of 69 questions)
  • Time limit: 180 minutes
Section 1: The Servlet Technology Model

  • For each of the HTTP Methods (such as GET, POST, HEAD, and so on) describe the purpose of the method and the technical characteristics of the HTTP Method protocol, list triggers that might cause a Client (usually a Web browser) to use the method; and identify the HttpServlet method that corresponds to the HTTP Method.
  • Using the HttpServletRequest interface, write code to retrieve HTML form parameters from the request, retrieve HTTP request header information, or retrieve cookies from the request.
  • Using the HttpServletResponse interface, write code to set an HTTP response header, set the content type of the response, acquire a text stream for the response, acquire a binary stream for the response, redirect an HTTP request to another URL, or add cookies to the response.
  • Describe the purpose and event sequence of the servlet life cycle: (1) servlet class loading, (2) servlet instantiation, (3) call the init method, (4) call the service method, and (5) call destroy method.

Section 2: The Structure and Deployment of Web Applications

  • Construct the file and directory structure of a Web Application that may contain (a) static content, (b) JSP pages, (c) servlet classes, (d) the deployment descriptor, (e) tag libraries, (d) JAR files, and (e) Java class files; and describe how to protect resource files from HTTP access.
  • Describe the purpose and semantics of the deployment descriptor.
  • Construct the correct structure of the deployment descriptor.
  • Explain the purpose of a WAR file and describe the contents of a WAR file, how one may be constructed.

Section 3: The Web Container Model

  • For the ServletContext initialization parameters: write servlet code to access initialization parameters; and create the deployment descriptor elements for declaring initialization parameters.
  • For the fundamental servlet attribute scopes (request, session, and context): write servlet code to add, retrieve, and remove attributes; given a usage scenario, identify the proper scope for an attribute; and identify multi-threading issues associated with each scope.
  • Describe the Web container request processing model; write and configure a filter; create a request or response wrapper; and given a design problem, describe how to apply a filter or a wrapper.
  • Describe the Web container life cycle event model for requests, sessions, and web applications;create and configure listener classes for each scope life cycle; create and configure scope attribute listener classes; and given a scenario, identify the proper attribute listener to use.
  • Describe the RequestDispatcher mechanism; write servlet code to create a request dispatcher; write servlet code to forward or include the target resource; and identify and describe the additional request-scoped attributes provided by the container to the target resource.

Section 4: Session Management

  • Write servlet code to store objects into a session object and retrieve objects from a session object.
  • Given a scenario describe the APIs used to access the session object, explain when the session object was created, and describe the mechanisms used to destroy the session object, and when it was destroyed.
  • Using session listeners, write code to respond to an event when an object is added to a session, and write code to respond to an event when a session object migrates from one VM to another.
  • Given a scenario, describe which session management mechanism the Web container could employ, how cookies might be used to manage sessions, how URL rewriting might be used to manage sessions, and write servlet code to perform URL rewriting.

Section 5: Web Application Security

  • Based on the servlet specification, compare and contrast the following security mechanisms: (a) authentication, (b) authorization, (c) data integrity, and (d) confidentiality.
  • In the deployment descriptor, declare a security constraint, a Web resource, the transport guarantee, the login configuration, and a security role.
  • Compare and contrast the authentication types (BASIC, DIGEST, FORM, and CLIENT-CERT); describe how the type works; and given a scenario, select an appropriate type.

Section 6: The JavaServer Pages (JSP) Technology Model

  • Identify, describe, or write the JSP code for the following elements: (a) template text, (b) scripting elements (comments, directives, declarations, scriptlets, and expressions), (c) standard and custom actions, and (d) expression language elements.
  • Write JSP code that uses the directives: (a) 'page' (with attributes 'import', 'session', 'contentType', and 'isELIgnored'), (b) 'include', and (c) 'taglib'.
  • Write a JSP Document (XML-based document) that uses the correct syntax.
  • Describe the purpose and event sequence of the JSP page life cycle: (1) JSP page translation, (2) JSP page compilation, (3) load class, (4) create instance, (5) call the jspInit method, (6) call the _jspService method, and (7) call the jspDestroy method.
  • Given a design goal, write JSP code using the appropriate implicit objects: (a) request, (b) response, (c) out, (d) session, (e) config, (f) application, (g) page, (h) pageContext, and (i) exception.
  • Configure the deployment descriptor to declare one or more tag libraries, deactivate the evaluation language, and deactivate the scripting language. 6.7 Given a specific design goal for including a JSP segment in another page, write the JSP code that uses the most appropriate inclusion mechanism (the include directive or the jsp:include standard action).

Section 7: Building JSP Pages Using the Expression Language (EL)

  • Given a scenario, write EL code that accesses the following implicit variables including pageScope, requestScope, sessionScope, and applicationScope, param and paramValues, header and headerValues, cookie, initParam and pageContext.
  • Given a scenario, write EL code that uses the following operators: property access (the . operator), collection access (the [] operator).

Section 8: Building JSP Pages Using Standard Actions

  • Given a design goal, create a code snippet using the following standard actions: jsp:useBean (with attributes: 'id', 'scope', 'type', and 'class'), jsp:getProperty, jsp:setProperty (with all attribute combinations), and jsp:attribute.
  • Given a design goal, create a code snippet using the following standard actions: jsp:include, jsp:forward, and jsp:param.

Section 9: Building JSP Pages Using Tag Libraries

  • For a custom tag library or a library of Tag Files, create the 'taglib' directive for a JSP page.
  • Given a design goal, create the custom tag structure in a JSP page to support that goal.
  • Given a design goal, use an appropriate JSP Standard Tag Library (JSTL v1.1) tag from the "core" tag library.

Section 10: Building a Custom Tag Library

  • Describe the semantics of the "Classic" custom tag event model when each event method (doStartTag, doAfterBody, and doEndTag) is executed, and explain what the return value for each event method means; and write a tag handler class.
  • Using the PageContext API, write tag handler code to access the JSP implicit variables and access web application attributes.
  • Given a scenario, write tag handler code to access the parent tag and an arbitrary tag ancestor.
  • Describe the semantics of the "Simple" custom tag event model when the event method (doTag) is executed; write a tag handler class; and explain the constraints on the JSP content within the tag.
  • Describe the semantics of the Tag File model; describe the web application structure for tag files; write a tag file; and explain the constraints on the JSP content in the body of the tag.

Section 11: Java EE Patterns

  • Given a scenario description with a list of issues, select a pattern that would solve the issues. The list of patterns you must know are: Intercepting Filter, Model-View-Controller, Front Controller, Service Locator, Business Delegate, and Transfer Object.
  • Match design patterns with statements describing potential benefits that accrue from the use of the pattern, for any of the following patterns: Intercepting Filter, Model-View-Controller, Front Controller, Service Locator, Business Delegate, and Transfer Object.

Wednesday, February 11, 2009

Sun Certified Programmer for the Java Platform, Standard Edition 5.0 (CX-310-055)

Exam Objectives:

Section 1: Declarations, Initialization and Scoping

  • Develop code that declares classes (including abstract and all forms of nested classes), interfaces, and enums, and includes the appropriate use of package and import statements (including static imports).
  • Develop code that declares an interface. Develop code that implements or extends one or more interfaces. Develop code that declares an abstract class. Develop code that extends an abstract class.
  • Develop code that declares, initializes, and uses primitives, arrays, enums, and objects as static, instance, and local variables. Also, use legal identifiers for variable names.
  • Develop code that declares both static and non-static methods, and - if appropriate - use method names that adhere to the JavaBeans naming standards. Also develop code that declares and uses a variable-length argument list.
  • Given a code example, determine if a method is correctly overriding or overloading another method, and identify legal return values (including covariant returns), for the method.
  • Given a set of classes and superclasses, develop constructors for one or more of the classes. Given a class declaration, determine if a default constructor will be created, and if so, determine the behavior of that constructor. Given a nested or non-nested class listing, write code to instantiate the class.

Section 2: Flow Control

  • Develop code that implements an if or switch statement; and identify legal argument types for these statements.
  • Develop code that implements all forms of loops and iterators, including the use of for, the enhanced for loop (for-each), do, while, labels, break, and continue; and explain the values taken by loop counter variables during and after loop execution.
  • Develop code that makes use of assertions, and distinguish appropriate from inappropriate uses of assertions.
  • Develop code that makes use of exceptions and exception handling clauses (try, catch, finally), and declares methods and overriding methods that throw exceptions.
  • Recognize the effect of an exception arising at a specified point in a code fragment. Note that the exception may be a runtime exception, a checked exception, or an error.
  • Recognize situations that will result in any of the following being thrown: ArrayIndexOutOfBoundsException,ClassCastException, IllegalArgumentException, IllegalStateException, NullPointerException, NumberFormatException, AssertionError, ExceptionInInitializerError, StackOverflowError or NoClassDefFoundError. Understand which of these are thrown by the virtual machine and recognize situations in which others should be thrown programatically.

Section 3: API Contents

  • Develop code that uses the primitive wrapper classes (such as Boolean, Character, Double, Integer, etc.), and/or autoboxing & unboxing. Discuss the differences between the String, StringBuilder, and StringBuffer classes.
  • Given a scenario involving navigating file systems, reading from files, or writing to files, develop the correct solution using the following classes (sometimes in combination), from BufferedReader,BufferedWriter, File, FileReader, FileWriter and PrintWriter.
  • Develop code that serializes and/or de-serializes objects using the following APIs from DataInputStream, DataOutputStream, FileInputStream, FileOutputStream, ObjectInputStream, ObjectOutputStream and Serializable.
  • Use standard J2SE APIs in the java.text package to correctly format or parse dates, numbers, and currency values for a specific locale; and, given a scenario, determine the appropriate methods to use if you want to use the default locale or a specific locale. Describe the purpose and use of the java.util.Locale class.
  • Write code that uses standard J2SE APIs in the java.util and java.util.regex packages to format or parse strings or streams. For strings, write code that uses the Pattern and Matcher classes and the String.split method. Recognize and use regular expression patterns for matching (limited to: . (dot), * (star), + (plus), ?, \d, \s, \w, [], ()). The use of *, +, and ? will be limited to greedy quantifiers, and the parenthesis operator will only be used as a grouping mechanism, not for capturing content during matching. For streams, write code using the Formatter and Scanner classes and the PrintWriter.format/printf methods. Recognize and use formatting parameters (limited to: %b, %c, %d, %f, %s) in format strings.

Section 4: Concurrency

  • Write code to define, instantiate, and start new threads using both java.lang.Thread and java.lang.Runnable.
  • Recognize the states in which a thread can exist, and identify ways in which a thread can transition from one state to another.
  • Given a scenario, write code that makes appropriate use of object locking to protect static or instance variables from concurrent access problems.
  • Given a scenario, write code that makes appropriate use of wait, notify, or notifyAll.

Section 5: OO Concepts

  • Develop code that implements tight encapsulation, loose coupling, and high cohesion in classes, and describe the benefits.
  • Given a scenario, develop code that demonstrates the use of polymorphism. Further, determine when casting will be necessary and recognize compiler vs. runtime errors related to object reference casting.
  • Explain the effect of modifiers on inheritance with respect to constructors, instance or static variables, and instance or static methods.
  • Given a scenario, develop code that declares and/or invokes overridden or overloaded methods and code that declares and/or invokes superclass or overloaded constructors.
  • Develop code that implements "is-a" and/or "has-a" relationships.

Section 6: Collections / Generics

  • Given a design scenario, determine which collection classes and/or interfaces should be used to properly implement that design, including the use of the Comparable interface.
  • Distinguish between correct and incorrect overrides of corresponding hashCode and equals methods, and explain the difference between == and the equals method.
  • Write code that uses the generic versions of the Collections API, in particular, the Set, List, and Map interfaces and implementation classes. Recognize the limitations of the non-generic Collections API and how to refactor code to use the generic versions.
  • Develop code that makes proper use of type parameters in class/interface declarations, instance variables, method arguments, and return types; and write generic methods or methods that make use of wildcard types and understand the similarities and differences between these two approaches.
  • Use capabilities in the java.util package to write code to manipulate a list by sorting, performing a binary search, or converting the list to an array. Use capabilities in the java.util package to write code to manipulate an array by sorting, performing a binary search, or converting the array to a list. Use the java.util.Comparator and java.lang.Comparable interfaces to affect the sorting of lists and arrays. Furthermore, recognize the effect of the "natural ordering" of primitive wrapper classes and java.lang.String on sorting.

Section 7: Fundamentals

  • Given a code example and a scenario, write code that uses the appropriate access modifiers, package declarations, and import statements to interact with (through access or inheritance) the code in the example.
  • Given an example of a class and a command-line, determine the expected runtime behavior.
  • Determine the effect upon object references and primitive values when they are passed into methods that perform assignments or other modifying operations on the parameters.
  • Given a code example, recognize the point at which an object becomes eligible for garbage collection, and determine what is and is not guaranteed by the garbage collection system. Recognize the behaviors of System.gc and finalization.
  • Given the fully-qualified name of a class that is deployed inside and/or outside a JAR file, construct the appropriate directory structure for that class. Given a code example and a classpath, determine whether the classpath will allow the code to compile successfully.
  • Write code that correctly applies the appropriate operators including assignment operators (limited to: =, +=, -=), arithmetic operators (limited to: +, -, *, /, %, ++, --), relational operators (limited to: <, <=, >, >=, ==, !=), the instanceof operator, logical operators (limited to: &, |, ^, !, &&, ||), and the conditional operator ( ? : ), to produce a desired result. Write code that determines the equality of two objects or two primitives.

Wednesday, February 4, 2009

JavaScript: TRIM Function

Following function is very helpful to trim the leading as well as trailing spaces in a string. To make use of this function, first add the following code snip(declaration) in your JS library or in head section of HTML.

String.prototype.trim = function() {
a = this.replace(/^\s+/, '');
return a.replace(/\s+$/, '');

Then you may call this function like:

Example No:1

alert("Test Case 1:" + " StrinValue ".trim()+"sabah" )

Example No:2

< name="textfieldid" type="text" onchange="this.value=this.value.trim()">