Nancy Den has Published 363 Answers

Nancy Den has Published 363 Answers

How to display the first element in a JComboBox in Java

Java 8 Object Oriented Programming Programming

Published on 06-May-2019 11:53:56

To display the first element in a JComboBox, use the getSelectedIndex():comboBox.setSelectedIndex(0);The following is an example to display the first element in a JComboBox in Java:Exampleimport java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JTextArea; public class SwingDemo { public static void main(String[] args) ... Read More

How to set tooltip text for JCheckBox in Java?

Java 8 Object Oriented Programming Programming

Published on 06-May-2019 11:39:13

For JCheckBox, use the following to set tooltip text:checkBox1.setToolTipText("Sports Football"); checkBox2.setToolTipText("Sports Tennis");Tooltip text is visible whenever you will place cursor on that particular text.The following is an example. Here, we have set the tooltip text for both the sports:Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingDemo { private ... Read More

How to change JLabel background and foreground color in Java?

Java 8 Object Oriented Programming Programming

Published on 06-May-2019 11:35:43

To change the JLabel foreground and background color, use the following methods:JLabel label; label.setForeground(new Color(120, 90, 40)); label.setBackground(new Color(100, 20, 70));The following is an example to change JLabel background and foreground color:Exampleimport java.awt.Color; import java.awt.Font; import javax.swing.*; import javax.swing.border.Border; public class SwingDemo { public static void main(String args[]) { ... Read More

How to filter non-null value in Java?

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:59:20

Let’s say the following is our List with string elements:List<String> leagues = Arrays.asList("BBL", "IPL", "MLB", "FPL", "NBA", "NFL");Now, create a stream and filter elements that end with a specific letter:Stream<String> stream = leagues.stream().filter(leagueName -> leagueName.endsWith("L"));Now, use Objects::nonnull for non-null values:List<String> list = stream.filter(Objects::nonNull).collect(Collectors.toList());The following is an example to filter non-null ... Read More

How to filter empty string values from a Java List?

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:57:19

Let’s say we have a String List with an empty value. Here, we have empty array elements before Football and after Squash:List<String> sports = Arrays.asList("", "Football", "Cricket", "Tennis", "Squash", "", "Fencing", "Rugby");Now filter the empty string values. At first, we have used Predicate to negate values:Stream<String> stream = sports.stream(); Predicate<String> ... Read More

How to count element after filtering in Java?

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:54:13

Let’s say the following is the String List:List<String> list = new ArrayList<>(); list.add("Tom"); list.add("John"); list.add("David"); list.add("Paul"); list.add("Gayle"); list.add("Narine"); list.add("Joseph");Now, let’s say you need to filter elements beginning with a specific letter. For that, use filter() and startsWith():long res = list .stream() .filter((s) -> s.startsWith("J")) .count();We have also ... Read More

How to convert Stream to TreeSet in Java?

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:52:01

Let us first create a Stream:Stream<String> stream = Stream.of("UK", "US", "India", "Australia", "Armenia", "Canada", "Poland");Now convert Stream to TreeSet:Set<String> set = stream.collect(Collectors.toCollection(TreeSet::new));The following is an example to convert String to TreeSet in Java:Exampleimport java.util.Set; import java.util.TreeSet; import java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public static void main(String[] args) ... Read More

How to convert string Stream to join them in Java?

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:49:37

Let us create string Stream:Stream<String> stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming");Convert the above string stream and join them with Collectors:final String str = stream.collect(Collectors.joining(" "));The following is an example to convert string Stream to join them:Exampleimport java.util.stream.Collectors; import java.util.stream.Stream; public class Demo { public ... Read More

Java Program to convert Stream to typed array

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:47:40

Let us first create a Stream:Stream<String> stream = Stream.of("Bing Bang Theory", "Vampire Diaries", "Game of Thrones", "Homecoming");Now convert the above stream to typed array:final String[] strArr = stream.toArray(String[]::new);The following is an example to convert Stream to typed array in Java:Exampleimport java.util.Arrays; import java.util.stream.Stream; public class Demo { public static ... Read More

How to right align the text in a ComboBox in Java

Java 8 Object Oriented Programming Programming

Published on 02-May-2019 11:44:52

To right align the text in a JComboBox, use the following:ComponentOrientation.RIGHT_TO_LEFTThe following is an example to right align the text in a ComboBox:Exampleimport java.awt.Component; import java.awt.ComponentOrientation; import javax.swing.DefaultListCellRenderer; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JList; public class SwingDemo extends JFrame { public SwingDemo() { JComboBox<String> combo = ... Read More

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