Merge pull request #310 from HaripriyaB/digitalwatchjava

Digital watch using Java

Author: tejan-singh

Java/DigitalWatchJava/DigitalWatch.java

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+import java.io.*;
+import java.util.*;
+import javax.swing.*;
+import java.awt.*;
+import java.text.*;
+
+class DigitalWatch implements Runnable {
+	// Initialise all the components of the application window 
+	JFrame f;
+	Thread t = null;
+	int hours = 0, minutes = 0, seconds = 0;
+	String timeString = "";
+	String timePeriod = "";
+	JButton b;
+
+	DigitalWatch() {
+		// frame for outliner
+		f = new JFrame();
+		//thread to execute time change
+		t = new Thread(this);
+		t.start();
+		// Display of time on a button for better UI
+		b = new JButton();
+		b.setBounds(100, 100, 100, 50);
+
+		f.add(b);
+		f.setSize(300, 300);
+		f.setLayout(null);
+		f.setVisible(true);
+	}
+
+	public void run() {
+		try {
+			while (true) {
+				// hours is checked if > 12 to change the time-period of the day(AM/PM)
+				Calendar cal = Calendar.getInstance();
+				hours = cal.get(Calendar.HOUR_OF_DAY);
+				if (hours > 12) {
+					hours -= 12;
+					timePeriod = "PM";
+				}
+				else{
+					timePeriod = "AM";
+				}
+				minutes = cal.get(Calendar.MINUTE);
+				seconds = cal.get(Calendar.SECOND);
+				// SimpleDateFormat used to get customized time format
+				SimpleDateFormat formatter = new SimpleDateFormat("hh:mm:ss");
+				Date date = cal.getTime();
+				//Time-period is appended with the time
+				timeString = formatter.format(date) +" "+ timePeriod;
+				printTime();
+				// interval given in milliseconds(1 sec = 1000 ms)
+				t.sleep(1000); 
+			}
+		} catch (Exception e) {
+		}
+	}
+
+	public void printTime() {
+		b.setText(timeString);
+	}
+
+	public static void main(String[] args) throws Exception {
+		// Watch initialized
+		new DigitalWatch();
+	}
+}

Java/DigitalWatchJava/README.md

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+# Simple Digital Watch written in Java
+The aim of this program is to display the current running time in digital format using Java swing and awt libraries. The output of this program open as new window which shows the current time and time-period(AM/PM).
+
+## Libraries Used:
+* [Java Swing](https://www.javatpoint.com/java-swing) - used to create window-based applications, built on the top of AWT API and entirely written in java.
+* [Java AWT(Abstract Windowing Toolkit)](https://www.javatpoint.com/java-awt) - an API to develop GUI or window-based applications in java.
+* [Java Text](http://web.deu.edu.tr/doc/oreily/java/fclass/ch16_js.htm) - used for Date format in this program.
+
+## Usage:
+`>> javac DigitalWatch.java`
+
+`>> java DigitalWatch`
+
+A window pops up showing the digital watch.
+
+## Output:
+<img src="output.png" width = 300 height=300>