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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to set JAVA_HOME environment variables on Windows OS in Java?
Once you have installed JDK version on your windows machine, you have to set up Environment Variables.Please find below steps to set the java pathGo to My Computer ---> Right Click on it ---> Advanced System Settings ---> Advanced Tab ---> Click on Environment VariablesNow you have to alter the “Path” variable under system variables such that it contains a path to Java Environment. Select the path variable and click on the “Edit” buttonBy default, Java is installed in “C:\Program Files\Java\jre version\bin” in case you have changed the location of installation, then add that pathClick on OK button and now ...
Read MoreHow to add empty border to a JButton in Java?
To add empty border to a component, use the BorderFactory class createEmptyBorder() method −Border emptyBorder = BorderFactory.createEmptyBorder(10, 10, 0, 0);To set the above border to a component, use the setBorder() method −JButton button = new JButton("Empty Border"); button.setBorder(emptyBorder);The following is an example to ad empty border to a JButton −Examplepackage my; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Container; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.border.Border; import javax.swing.border.SoftBevelBorder; public class SwingDemo { public static void main(String args[]) { JFrame frame = new JFrame("Demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Border raisedBorder = new SoftBevelBorder(SoftBevelBorder.RAISED, ...
Read MoreHow to create a Titleless and Borderless JFrame in Java?
To create a Titleless and Borderless JFrame, use the setUndecorated() method and set it to TRUE −JFrame frame = new JFrame("Register!"); frame.setUndecorated(true);The following is an example to create a titleless and borderless JFrame −Examplepackage my; import java.awt.GridLayout; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPasswordField; import javax.swing.JTextField; import javax.swing.SwingConstants; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Register!"); JLabel label1, label2, label3; frame.setLayout(new GridLayout(2, 2)); label1 = new JLabel("Id", SwingConstants.CENTER); label2 = new JLabel("Age", SwingConstants.CENTER); ...
Read MoreAdding a new column with the current time as a default value in MySQL?
For this, you can use the DEFAULT CURRENT_TIMESTAMP clause in MySQL. Following is the syntax −CREATE TABLE yourTableName ( yourColumnName1 dataType1, yourColumnName timestamp DEFAULT CURRENT_TIMESTAMP );Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> DueDate timestamp default current_timestamp -> ); Query OK, 0 rows affected (0.86 sec)Now you can insert some records in the table using insert command −mysql> insert into DemoTable values(); Query OK, 1 row affected (0.16 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+----+---------------------+ ...
Read MoreCount the number of objects using Static member function in C++
Here we will see how to count number of objects are created from a specific class using some static member functions. The static members are class properties, not the object properties. For a single class there will be only one instance for static members. No new members are created for each objects.In this problem we are using one static counter variable to keep track the number of objects, then static member will be there to display the count value.When a new object is created, so the constructor will be called. Inside the constructor, the count value is increased. Thus we ...
Read MoreCompiling multiple .cpp files in c++ program
Here we will see how to compile multiple cpp file in C++ program. The task is very simple. We can provide the names as a list to the g++ compiler to compile them into one executable fileTo compile multiple files like abc.cpp, and xyz.cpp at once, the syntax will be like this −g++ abc.cpp xyz.cppTo run the program, we can use this −./a.outExamplefloat area(float r){ return (3.1415*r*r); //area of a circle } float area(float l, float w) { return (l * w); //area of a rectangle }Example#include #include "area.cpp" using namespace std; main() { cout
Read MoreHow to get the table name of the current ResultSet using JDBC?
You can get the name of the table in the current ResultSet object using the getTableName() method of the ResultSetMetaData interface. This method accepts an integer value representing the index of a column and, returns a String value representing the name of the table that contains the given column.Let us create a table with name MyPlayers in MySQL database using CREATE statement as shown below −CREATE TABLE MyPlayers( ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Date_Of_Birth date, Place_Of_Birth VARCHAR(255), Country VARCHAR(255), PRIMARY KEY (ID) );Now, we will insert 7 records in MyPlayers table using INSERT statements −insert into ...
Read MoreHow to get the number of rows and columns of a JTable in Java Swing
To count the number of rows of a table, use the getRowCount() method −table.getRowCount()To count the number of columns of a table, use the getColumnCount() method −table.getColumnCount()The following is an example to get the number of rows and columns of a JTable −Examplepackage my; import java.awt.Font; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.DefaultTableModel; public class SwingDemo { public static void main(String[] argv) throws Exception { DefaultTableModel tableModel = new DefaultTableModel(); JTable table = new JTable(tableModel); tableModel.addColumn("Language/ Technology"); tableModel.addColumn("Text Tutorial"); tableModel.addColumn("Video Tutorial"); ...
Read MoreHow to expand JTree row to display all the nodes and child nodes in Java
To expand JTree row to display all the nodes and child nodes, use the expandRow() method in Java. At first, create a node −DefaultMutableTreeNode node = new DefaultMutableTreeNode("Project");Now, add nodes to the node created above −DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("App"); DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Website"); DefaultMutableTreeNode node3 = new DefaultMutableTreeNode("WebApp"); node.add(node1); node.add(node2); node.add(node3);Now, create more nodes and set them as child nodes for the nodes we creted above −DefaultMutableTreeNode one = new DefaultMutableTreeNode("Learning website"); DefaultMutableTreeNode two = new DefaultMutableTreeNode("Business website"); DefaultMutableTreeNode three = new DefaultMutableTreeNode("News publishing website"); DefaultMutableTreeNode four = new DefaultMutableTreeNode("Android app"); DefaultMutableTreeNode five = new DefaultMutableTreeNode("iOS app"); DefaultMutableTreeNode ...
Read MoreSelect column names containing a string in MySQL?
For this, you can use SHOW COLUMNS command. Following is the syntax. Here, we have set the string using LIKE −SHOW COLUMNS FROM yourTableName LIKE ‘yourStringValue’;Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> FirstName varchar(20), -> LastName varchar(20) -> ); Query OK, 0 rows affected (0.69 sec)Here is the query to select column names containing a specific string −mysql> SHOW COLUMNS FROM DemoTable LIKE 'FirstName';Output+-----------+-------------+------+-----+----------+-------+ | Field | Type | Null | ...
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