Introducing JavaBeans Lesson 2A / Slide 1 of 30 JDBC and JavaBeans Pre-assessment Questions 1.Which of the given symbols is used as a placeholder for PreparedStatement ? a.# b.* c.? d.% 2.In SQL Server 2000, a _______ is generated when you execute a stored procedure. a.Query plan b.Query c.ResultSet d.Rowset

Introducing JavaBeans Lesson 2A / Slide 2 of 30 JDBC and JavaBeans Pre-assessment Questions (Contd.) 3.Which of the following parameters cannot be used in a stored procedure? a.IN b.OUT c.OUTIN d.INOUT 4.Which of the following enables you to retrieve the information about a ResultSet ? a.DatabaseMetaData b.ResultSetData c.RowSetData d.ResultSetMetaData

Introducing JavaBeans Lesson 2A / Slide 3 of 30 JDBC and JavaBeans Pre-assessment Questions (Contd.) 5.The batch update operations can throw two types of exceptions, __________and ___________. a.SQLException and BatchUpdateException b.SQLExceptio n and UpdateException c.BatchException and BatchUpdateException d.BatchException and SQLException

Introducing JavaBeans Lesson 2A / Slide 4 of 30 JDBC and JavaBeans Solutions to Pre-assessment Questions 1.c. ? 2.a. Query plan 3.c. OUTIN 4.d. ResultSetMetaData 5.a. SQLException and BatchUpdateException

Introducing JavaBeans Lesson 2A / Slide 5 of 30 JDBC and JavaBeans Objectives In this lesson, you will learn about: Features of JavaBeans Associating predefined events with sample JavaBeans Testing JavaBeans using BDK Creating sample JavaBean applet using BDK Creating user-defined JavaBean Creating manifest and JAR files for a JavaBean

Introducing JavaBeans Lesson 2A / Slide 6 of 30 JDBC and JavaBeans JavaBean Concepts A software component is a reusable object that can be plugged into any target software application. You can develop software components using various programming languages, such as C, C++, Java, and Visual Basic. JavaBeans are reusable and platform-independent software components developed using the Java programming language. The classes and interfaces defined in the java.beans package enable you to create JavaBeans. The JavaBean components can exist in one of the following three phases of development: Construction phase Build phase Execution phase

Introducing JavaBeans Lesson 2A / Slide 7 of 30 JDBC and JavaBeans JavaBean Concepts (Contd.) Elements of a JavaBean Properties: Refer to the private data members of a JavaBean that define the behavior of the JavaBeans. Methods: Refer to public member functions of a JavaBean that are used to modify the JavaBean properties. Events: Refer to the messages that one JavaBean components sends to another JavaBean components.

Introducing JavaBeans Lesson 2A / Slide 8 of 30 JDBC and JavaBeans JavaBean Concepts (Contd.) The JavaBean Component Specification Customization: Is the ability of JavaBean to allow its properties to be changed in build and execution phase. Persistence: Is the ability of JavaBean to save its state to disk or storage device and restore the saved state when the JavaBean is reloaded. Communication: Is the ability of JavaBean to notify change in its properties to other JavaBeans or the container. Introspection: Is the ability of a JavaBean to allow an external application to query the properties, methods, and events supported by it.

Introducing JavaBeans Lesson 2A / Slide 9 of 30 JDBC and JavaBeans JavaBean Concepts (Contd.) Services of JavaBean Components Builder support: Enables you to create and group multiple JavaBeans in an application. Layout: Allows multiple JavaBeans to be arranged in a development environment. Interface publishing: Enables multiple JavaBeans in an application to communicate with each other. Event handling: Refers to firing and handling of events associated with a JavaBean. Persistence: Enables you to save the last state of JavaBean.

Introducing JavaBeans Lesson 2A / Slide 10 of 30 JDBC and JavaBeans JavaBean Concepts (Contd.) Types of JavaBeans Control JavaBeans: Are used to create GUI components that can be plugged into any application. Container JavaBeans: Are used to hold other JavaBeans. Invisible Runtime JavaBeans: Are used to create components that perform a specific task in the background of an application.

Introducing JavaBeans Lesson 2A / Slide 11 of 30 JDBC and JavaBeans Beans Development Kit Is a development environment to create, configure, and test JavaBeans. The features of BDK environment are: Provides a GUI to create, configure, and test JavaBeans. Enables you to modify JavaBean properties and link multiple JavaBeans in an application using BDK. Provides a set of sample JavaBeans. Enables you to associate pre-defined events with sample JavaBeans.

Introducing JavaBeans Lesson 2A / Slide 12 of 30 JDBC and JavaBeans Beans Development Kit (Contd.) Identifying BDK Components Execute the run.bat file of BDK to start the BDK development environment. The components of BDK development environment are: ToolBox BeanBox Properties Method Tracer

Introducing JavaBeans Lesson 2A / Slide 13 of 30 JDBC and JavaBeans Beans Development Kit (Contd.) ToolBox window: Lists the sample JavaBeans of BDK. The following figure shows the ToolBox window:

Introducing JavaBeans Lesson 2A / Slide 14 of 30 JDBC and JavaBeans Beans Development Kit (Contd.) BeanBox window: Is a workspace for creating the layout of JavaBean application. The following figure shows the BeanBox window:

Introducing JavaBeans Lesson 2A / Slide 15 of 30 JDBC and JavaBeans Beans Development Kit (Contd.) Properties window: Displays all the exposed properties of a JavaBean. You can modify JavaBean properties in the properties window. The following figure shows the Properties window:

Introducing JavaBeans Lesson 2A / Slide 16 of 30 JDBC and JavaBeans Beans Development Kit (Contd.) Method Tracer window: Displays the debugging messages and method calls for a JavaBean application. The following figure shows the Method Tracer window:

Introducing JavaBeans Lesson 2A / Slide 17 of 30 JDBC and JavaBeans Demonstration-Creating Sample JavaBean Applet using BDK Problem Statement Create an applet that shows the sample Molecule JavaBean rotating along its X-axis.

Introducing JavaBeans Lesson 2A / Slide 18 of 30 JDBC and JavaBeans Demonstration-Creating Sample JavaBean Applet using BDK (Contd.) Solution To create an applet that shows a Molecule JavaBean rotating along its X-axis, you need to perform the following tasks: 1.Associating pre-defined event with sample JavaBeans. 2.Converting the JavaBean to an applet.

Introducing JavaBeans Lesson 2A / Slide 19 of 30 JDBC and JavaBeans User-Defined JavaBean The coding conventions to create a user-defined JavaBean are: Implement the java.io.Serializable interface. Define an empty constructor to initialize the instances of a JavaBean. Define the accessor and mutator methods for the exposed properties of a JavaBean.

Introducing JavaBeans Lesson 2A / Slide 20 of 30 JDBC and JavaBeans User-Defined JavaBean (Contd.) Accessor and Mutator Methods: Are used to access the exposed properties of a JavaBean. The accessor methods: Are used to retrieve the values of JavaBean properties. Are also called get methods. The mutator methods: Are used to specify the values of JavaBean properties. Are also called set methods.

Introducing JavaBeans Lesson 2A / Slide 21 of 30 JDBC and JavaBeans User-Defined JavaBean (Contd.) Manifest and JAR Files Manifest File The manifest file for a JavaBean application contains a list of all the class files that make up a JavaBean. The entry in the manifest file enables the target application to recognize the JavaBean classes for an application. For example, the entry for the SpellCheck JavaBean in the manifest file is as shown: Name: SpellCheck.class Java-Bean: True

Introducing JavaBeans Lesson 2A / Slide 22 of 30 JDBC and JavaBeans User-Defined JavaBean (Contd.) Manifest File (Contd.) The rules to create a manifest file are: Press the Enter key after typing each line in the manifest file. Leave a space after the colon. Type a hyphen between Java and Bean. No blank line between the Name and the Java-Bean entry.

Introducing JavaBeans Lesson 2A / Slide 23 of 30 JDBC and JavaBeans User-Defined JavaBean (Contd.) Java Archive File The files of a JavaBean application are compressed and grouped as JAR files to reduce the size and the download time of the files. The syntax to create a JAR file from the command prompt is: jar The file_names is a list of files for a JavaBean application that are stored in the JAR file.

Introducing JavaBeans Lesson 2A / Slide 24 of 30 JDBC and JavaBeans User-Defined JavaBean (Contd.) Java Archive File (Contd.) The various options that you can specify while creating a JAR file are: c: Indicates the new JAR file is created. f: Indicates that the first file in the file_names list is the name of the JAR file. m: Indicates that the second file in the file_names list is the name of the manifest file. t: Indicates that all the files and resources in the JAR file are to be displayed in a tabular format. v: Indicates that the JAR file should generate a verbose output. x: Indicates that the files and resources of a JAR file are to be extracted. o: Indicates that the JAR file should not be compressed. m: Indicates that the manifest file is not created.

Introducing JavaBeans Lesson 2A / Slide 25 of 30 JDBC and JavaBeans Demonstration-Creating User-Defined JavaBean Problem Statement Create a user-defined JavaBean having a label. Allow the user to change the caption of the user-defined JavaBean at runtime.

Introducing JavaBeans Lesson 2A / Slide 26 of 30 JDBC and JavaBeans Demonstration-Creating User-Defined JavaBean (Contd.) Solution To create a user-defined JavaBean that changes the caption of a label, you need to perform the following tasks: 1.Code the user-defined JavaBean 2.Package the JavaBean 3.Load and test the JavaBean

Introducing JavaBeans Lesson 2A / Slide 27 of 30 JDBC and JavaBeans Summary In this lesson, you learned: A component is a reusable object that can be plugged into any target software application. JavaBeans are reusable and platform-independent software components that are created using the Java programming language. The various features of JavaBean are: Customization Persistence Communication Introspection

Introducing JavaBeans Lesson 2A / Slide 28 of 30 JDBC and JavaBeans Summary (Contd.) JavaBean components provide the following services to the container in which they are grouped together: Builder support Layout Interface publishing Event handling Persistence There are three types of JavaBeans, Control JavaBeans, Container JavaBeans, and Invisible runtime JavaBeans. BDK is a development environment to test and create JavaBeans. The ToolBox window of BDK displays the sample JavaBeans defined in the BDK. The BeanBox window of BDK enables you to test JavaBeans and create applications using various JavaBeans as components.

Introducing JavaBeans Lesson 2A / Slide 29 of 30 JDBC and JavaBeans Summary (Contd.) The properties window displays the properties of the currently selected JavaBean component. The method tracer window of BDK displays the debugging messages and method calls for the BDK environment. BDK provides pre-defined events that can be associated with the sample JavaBean components in an application. The pre-defined events for the sample JavaBeans are displayed in the EventTargetDialog window of BDK. The MakeApplet utility of BDK enables you to create an applet file for a JavaBean application. The applet file can be run using a Web browser or the applet viewer utility of Java. You can also create user-defined JavaBeans using the classes and interfaces provided by the java.beans package.

Introducing JavaBeans Lesson 2A / Slide 30 of 30 JDBC and JavaBeans Summary (Contd.) The accessor and mutator methods of user-defined JavaBean are used to retrieve and specify the value of JavaBean properties. The user-defined JavaBean implements the java.io.Serializable interface. A manifest file is a text file that provides information about the class files that represent a JavaBean. JAR files are platform-independent files that are used to package all the classes and the associated resources for a JavaBean application. The JAR file for the user-defined JavaBean is loaded in the ToolBox window using the File  LoadJar command of the BeanBox window.