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Pre-assessment Questions Which of the given symbols is used as a placeholder for PreparedStatement ? # * ? % In SQL Server 2000, a _______ is generated when you execute a stored procedure. Query plan Query ResultSet Rowset. Pre-assessment Questions (Contd.)
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Pre-assessment Questions • Which of the given symbols is used as a placeholder for PreparedStatement? • # • * • ? • % • In SQL Server 2000, a _______ is generated when you execute a stored procedure. • Query plan • Query • ResultSet • Rowset JDBC and JavaBeans
Pre-assessment Questions (Contd.) • Which of the following parameters cannot be used in a stored procedure? • IN • OUT • OUTIN • INOUT • Which of the following enables you to retrieve the information about a ResultSet? • DatabaseMetaData • ResultSetData • RowSetData • ResultSetMetaData JDBC and JavaBeans
Pre-assessment Questions (Contd.) • The batch update operations can throw two types of exceptions, __________and ___________. • SQLException and BatchUpdateException • SQLException and UpdateException • BatchException and BatchUpdateException • BatchException and SQLException JDBC and JavaBeans
Solutions to Pre-assessment • Questions • c. ? • a. Query plan • c. OUTIN • d. ResultSetMetaData • a. SQLException and BatchUpdateException 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 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 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. 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. 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. 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. 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. 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 JDBC and JavaBeans
Beans Development Kit (Contd.) • ToolBox window: Lists the sample JavaBeans of BDK. • The following figure shows the ToolBox window: 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: 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: 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: 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. 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: • Associating pre-defined event with sample JavaBeans. • Converting the JavaBean to an applet. 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. 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. 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 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. 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 <options> <file_names> • The file_names is a list of files for a JavaBean application that are stored in the JAR file. 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. 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. 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: • Code the user-defined JavaBean • Package the JavaBean • Load and test the JavaBean 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 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. 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. 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 FileLoadJar command of the BeanBox window. JDBC and JavaBeans