Explain Java Swing and data types
A Graphical User Interface (GUI) toolkit that includes the components of the GUI is a Swing in Java. To render sophisticated GUI components for Java applications, Swing offers a rich collection of widgets and packages. Swing is part of the Java Foundation Classes(JFC), an API for GUI-providing Java programs.
The Java Swing library is developed on top of an older, platform-dependent GUI toolkit, the Java Abstract Widget Toolkit (AWT). You can use the programming components of the Java online training Interface from the library, such as buttons, text boxes, etc., and you do not have to build the components from scratch.
What's a Container Class?
Container groups are classes that can be composed of other elements. So, we need at least one container object to build a Java GUI. There are 3 types of containers for Java Swing.
- Panel: It is a pure container and in itself is not a window. A panel's sole aim is to arrange the components through a window.
- Frame: With its title and icons, it is a completely functional window.
- Dialog: You can think of it as a pop-up window that pops out when you need to show a message. Like the door, it is not a completely functional window.
What is a GUI?
A simple-to-use visual experience builder for Java applications is the GUI (Graphical User Interface) in Java. It is primarily made up of graphical components from which the user can interact with an application, such as buttons, labels, windows, etc. The GUI plays an important role in developing Java applications with simple interfaces.
Example from GUI
Now, let's grasp the GUI with Java Swing examples in this Swing Java.
Step 1)
In an editor, copy the following code
import javax.swing.*;
class gui{
public static void main(String args[]){
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,300);
JButton button = new JButton("Press");
frame.setVisible(true);
}
}
Step 2)
Code Save, Compile and Run.
Step 3)
Let's add a button to our system now. Copying the following code from a given Java GUI example into an editor.
import javax.swing.*;
class gui{
public static void main(String args[]){
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,300);
JButton button1 = new JButton("Press");
frame.getContentPane().add(button1);
frame.setVisible(true);
}
}
Step 4)
Has the code executed? You're going to get a big button.
Step 5)
How about two buttons to add? Copy into an editor the following code.
import javax.swing.*;
class gui{
public static void main(String args[]){
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,300);
JButton button1 = new JButton("Button 1");
JButton button2 = new JButton("Button 2");
frame.getContentPane().add(button1);
frame.getContentPane().add(button2);
frame.setVisible(true);
}
}
Step 6)
The program is saved, compiled, and run.
Step 7)
Performance unexpected =? There are overlapping keys.
Manager Layout
The Layout Manager is used within a container to layout (or arrange) the GUI components. Many layout managers are available, but the most frequently used are—
Border Layout
In up to five locations, a Border Arrangement positions elements: top, bottom, left, right, and middle. For any java JFrame, it is the default layout manager for the following.
Flow Layout
For all panels, FlowLayout is the default layout manager. It simply lays out components one after the other in a single row.
Using Java Swing to build GUI Components
Grid Bag Layout
It is the most technical one of all layouts. By placing them within a grid of cells, it aligns components, allowing components to span more than one cell.
import javax.swing.*;
import java.awt.*;
class gui {
public static void main(String args[]) {
JFrame frame = new JFrame("Chat Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
JMenuBar mb = new JMenuBar();
JMenu m1 = new JMenu("FILE");
JMenu m2 = new JMenu("Help");
mb.add(m1);
mb.add(m2);
JMenuItem m11 = new JMenuItem("Open");
JMenuItem m22 = new JMenuItem("Save as");
m1.add(m11);
m1.add(m22);
JPanel panel = new JPanel(); // the panel is invisible at output result
JLabel label = new JLabel("Enter Text");
JButton send = new JButton("Send");
JButton reset = new JButton("Reset");
panel.add(tf);
panel.add(send);
panel.add(reset);
JTextArea ta = new JTextArea();
//Adding Components to the frame.
frame.getContentPane().add(BorderLayout.SOUTH, panel);
frame.getContentPane().add(BorderLayout.NORTH, mb);
frame.getContentPane().add(BorderLayout.CENTER, ta);
frame.setVisible(true);
}
}
Java Data types
Boolean type
With the Boolean keyword, the Boolean data form is declared. It has only two values that are possible: true and false. For simple flagging purposes, this data form can be used to monitor true/ false conditions for learn java online.
Char
A single 16-bit Unicode character is the Char Data Type. It has a '\u0000' (or 0) minimum value and a '\uffff' maximum value (or 65,535 inclusive).
Byte
With the byte keyword, the byte data type is declared. The minimum value may be -128 and the maximum value maybe 1277 (inclusive). The default value is 0 by default. If a variable is expected to contain a small value in the specified range, a byte data type may be used instead of int. It serves two purposes.
Save space as a byte is an 8-bit signed integer 4 times smaller than int.
Their limitations help explain the code, as a form of documentation, the fact that the range of a variable is limited can serve.
Short Condensed
With a short keyword, the short data type can be declared. A 16-bit signed twos-complement integer is the short data form. Its value ranges from -32,768 to 32,767 (inclusive). The value is 0. by default. Where the value of the variable lies between the range, the short data form may be used in place of int. It will, as mentioned above, serve two purposes.
Int
Please note that even Java 8 is signed with int. But several techniques handle them as if they were unsigned, but there is no way in Java 8 or beyond to declare an Unsigned int.
To obtain the minimum and maximum value provided by int, try to print the below code. A variable can be assigned to these values.
Integer.MAX VALUE VALUE
Integer.MIN VALUE MIN VALUE
Long,
A 64-bit two complement integer is the long data form. It has a minimum value of -263 and a maximum value of 263-1, respectively. You may say, in a simple way, that it is an improved version of int. When you need a set of values wider than those given by int, this data form should be used.
You can use the form of long data within the Java 8 version and later to present the unsigned 64-bit length. Also, this consists of a minimum value of “0” and a maximum value of “264-1”.
Please note that Long is signed, also in Java 8. But certain ways handle them as if they were unsigned. CompareUnsigned, DivideUnsigned are some of the Long Wrapper class methods that support unsigned arithmetic operations.
Float
Single-precision(32 bit) IEEE 754 floating-point is the float data form. Float type variables are useful when you need a fractional component, but do not need a high degree of accuracy. 23 bit is used for the fractional component in Single Accuracy. For normal day to day calculations, this data form can be used.
Double data form
The double data form is an IEEE 754 floating-point double-precision (64-bit). For more accuracy, it is a floating-point. For the fractional portion, 52 bits are used in Double-precision. As double-precision requires more memory than single-precision, it is therefore not recommended that it be used for normal calculations. It is used for scientific calculations primarily.
Conclusion
Java is a statistic meaning there all variables. You must first be declared before they can be used. This means the name and form of the variable must be specified before it can be used in the code. You can learn more about this through Core Java online training.
