Object Oriented Programming Articles

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Customize the tooltip font, color , background and foreground color in Java

George John
George John
Updated on 30-Jul-2019 2K+ Views

To customize the tooltip font, color and background, use UIManager.UIManager.put("ToolTip.background", Color.ORANGE); UIManager.put("ToolTip.foreground", Color.BLACK); UIManager.put("ToolTip.font", new Font("Arial", Font.BOLD, 14));Above, we have set the font with −Tooltip.fontWe have set the foreground and background color with the following above −ToolTip.foreground ToolTip.backgroundThe following is an example to customize tooltip −Examplepackage my; import java.awt.Color; import java.awt.Font; import java.awt.GraphicsEnvironment; import java.awt.GridLayout; import java.awt.Point; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPasswordField; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; public class SwingDemo {    public static void main(String[] args) throws Exception {       JFrame.setDefaultLookAndFeelDecorated(true);       JFrame frame = new JFrame("Register!");       JLabel label1, label2, ...

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How can I set scrollbars to never appear in Java?

Ankith Reddy
Ankith Reddy
Updated on 30-Jul-2019 168 Views

To set scrollbars to never appear, use the JScrollPane.HORIZONTAL_SCROLLBAR_NEVER and JScrollPane.VERTICAL_SCROLLBAR_NEVER. Let’s say you created a Box with some button components. Now, create a JScrollPane:JScrollPane scrollPane = new JScrollPane();Set the Viewport view as Box:scrollPane.setViewportView(box);Now, set the scrollbars to never appear:scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);The following is an example to set scrollbars to never appear:Examplepackage my; import java.awt.BorderLayout; import java.awt.Dimension; import javax.swing.Box; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JScrollPane; public class SwingDemo {    public static void main(String args[]) {       JFrame frame = new JFrame("Demo");       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       JButton button1 = new JButton("One");       JButton button2 ...

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How can I append text to JTextArea in Java?

George John
George John
Updated on 30-Jul-2019 3K+ Views

To append text to JTextArea, use the component’s append() method. Let’sa say the following is our text in the JTextArea -JTextArea textArea = new JTextArea("The text added here is just for demo. "+ "This demonstrates the usage of JTextArea in Java. ");Now, append text to the same textArea -textArea.append("In this example we have deleted some text from the beginning."+ "We have also appended some text.");The following is an example to append text to JTextArea -Examplepackage my; import java.awt.GridLayout; import javax.swing.*; public class SwingDemo {    SwingDemo() {       JFrame frame = new JFrame("Demo");       JTextArea textArea ...

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How to encrypt a CLOB datatype in JDBC?

Smita Kapse
Smita Kapse
Updated on 30-Jul-2019 406 Views

Creating an Encrypted LOB(CLOB or, BLOB)Oracle database from 11g onwards provides SecureFiles feature to encrypt the Large object files (LOBs). You can create a secure file using the SECUREFILE keyword as −CREATE TABLE table_name (    myClob CLOB ) LOB(myClob) STORE AS SECUREFILE;You can encrypt a secured file using Encrypt option for encryption you can use 3DES168 or, AES128 or, AES192 or, AES256 algorithm.CREATE TABLE encrypt_tab (    myClob CLOB ) LOB(myClob) STORE AS SECUREFILE encrypt_lob(    ENCRYPT USING 'AES256' );

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How to determine database type (name) for a given JDBC connection?

Smita Kapse
Smita Kapse
Updated on 30-Jul-2019 4K+ Views

One way to get the name of the underlying database you have connected with is by invoking the getDatabaseProductName() method of the DatabaseMetaData interface. This method returns the name of the underlying database in String format.Therefore, to retrieve the name of your current database using Java code −Retrieve the DatabaseMetaData object of the current Connection using the getMetaData() method.//Retrieving the meta data object DatabaseMetaData metaData = con.getMetaData();Then, get the product name of the underlying database you have connected to using the getDatabaseProductName() method of the DatabaseMetaData interface as −//retrieving the name of the database String product_name = metaData.getDatabaseProductName();ExampleFollowing JDBC program ...

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JDBC Class.forName vs DriverManager.registerDriver

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 6K+ Views

To connect with a database using JDBC you need to select get the driver for the respective database and register the driver. You can register a database driver in two ways −Using Class.forName() method − The forName() method of the class named Class accepts a class name as a String parameter and loads it into the memory, Soon the is loaded into the memory it gets registered automatically.Class.forName("com.mysql.jdbc.Driver");ExampleFollowing JDBC program establishes connection with MySQL database. Here, we are trying to register the MySQL driver using the forName() method.import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class RegisterDriverExample {    public static ...

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Is it mandatory to register the driver while working with JDBC?

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 821 Views

Initially, till Java6 it is needed to register the driver using Class.forname() or the registerDriver() method before establishing connection with the database.But, since Java 1.6, JDBC 4.0 API, there is no need to register the driver explicitly, You Just need to set the Class path for the JDBC 4.X driver, Java automatically detects the Driver class and loads it.ExampleIn the following JDBC program we are trying connect with MySQL database first of all include the dependency for the MySQL driver in the pom.xml of your project.    mysql    mysql-connector-java    8.0.16 Then, without registering the MySQL driver class com.mysql.jdbc.Driver ...

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What is the MySQL datatype to store DATALINK object in JDBC

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 476 Views

A DATALINK object represents an URL value which refers to an external resource (outside the current database/data source), which can be a file, directory etc..MySQL does not provide any separate datatype to store DATALINK/URL value you need to store using TEXT or VARCHAR datatypes as shown in the following query −CREATE TABLE tutorials_data (    tutorial_id INT PRIMARY KEY AUTO_INCREMENT,    tutorial_title VARCHAR(100),    tutorial_author VARCHAR(40),    submission_date date,    tutorial_link VARCHAR(255) );Following JDBC program establishes a connection with MYSQL database, creates a table with name tutorials_data. In this table we are creating a column with name tutorial_link which stores ...

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How to handle indexes in JavaDB using JDBC program?

Anvi Jain
Anvi Jain
Updated on 30-Jul-2019 1K+ Views

Indexes in a table are pointers to the data, these speed up the data retrieval from a table. If we use indexes, the INSERT and UPDATE statements get executed in a slower phase. Whereas SELECT and WHERE get executed with in lesser time.Creating an indexCTREATE INDEX index_name on table_name (column_name);Displaying the IndexesSHOW INDEXES FROM table_name;Dropping an indexDROP INDEX index_name;Following JDBC program creates a table with name Emp in JavaDB. creates an index on it, displays the list of indexes and, deletes the created index.Exampleimport java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; public class IndexesExample {    public static void main(String ...

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How to set the initial value of an auto-incremented column in MySQL using JDBC?

Nishtha Thakur
Nishtha Thakur
Updated on 30-Jul-2019 2K+ Views

While creating a table, in certain scenarios, we need values to column such as ID, to be generated/incremented automatically. Various databases support this feature in different ways.In MySQL database you can declare a column auto increment using the following syntax.CREATE TABLE table_name(    ID INT PRIMARY KEY AUTO_INCREMENT,    column_name1 data_type1,    column_name2 data_type2,    column_name3 data_type3,    column_name4 data_type4,    ............ ........... );While inserting records in a table there is no need to insert value under the auto-incremented column. These will be generated automatically.Setting the initial valueBy default, the initial value of the auto-incremented column will be 1. You ...

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