Java 22 new features

eazybytes · eazybytes · commit 531e460addf3 · 2024-04-18T14:35:59.000+05:30
diff --git a/section29/.gitignore b/section29/.gitignore
@@ -0,0 +1,29 @@
+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
diff --git a/section29/src/com/eazybytes/java22/UnnamedPatterns.java b/section29/src/com/eazybytes/java22/UnnamedPatterns.java
@@ -0,0 +1,38 @@
+package com.eazybytes.java22;
+
+public class UnnamedPatterns {
+
+    public static void main(String[] args) {
+        Vehicle vehicle = new Truck("Toyota");
+
+        switch (vehicle) {
+            case Car _ -> processCar(vehicle);
+            case Bike _ -> processBike(vehicle);
+            case Truck _ -> processTruck(vehicle);
+        }
+    }
+
+    public static void processCar(Vehicle vehicle) {
+        if(vehicle instanceof Car car) {
+            System.out.println("Processing car model: " + car.getModel());
+        }
+    }
+
+    public static void processBike(Vehicle vehicle) {
+        if(vehicle instanceof Bike bike) {
+            System.out.println("Processing bike brand: " + bike.getBrand());
+        }
+    }
+
+    public static void processTruck(Vehicle vehicle) {
+        if(vehicle instanceof Truck truck) {
+            System.out.println("Processing truck manufacturer: " + truck.getManufacturer());
+        }
+    }
+
+}
+
+
+
+
+
diff --git a/section29/src/com/eazybytes/java22/UnnamedVariables.java b/section29/src/com/eazybytes/java22/UnnamedVariables.java
@@ -0,0 +1,77 @@
+package com.eazybytes.java22;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class UnnamedVariables {
+
+    public static void main(String[] args) {
+        // Scenario 1
+        List<String> wordList = Arrays.asList("apple", "banana", "orange", "grape", "kiwi");
+        int totalWords = countWords(wordList);
+        System.out.println(totalWords);
+
+        // Scenario 2
+        List<String> fruits = Arrays.asList("apple", "banana", "orange");
+        Map<String, String> fruitMap = fruits.stream()
+                .collect(Collectors.toMap(f -> f, _ -> "Fruit"));
+        System.out.println(fruitMap);
+
+        // Scenario 3
+        boolean isValid = convertAndDisplay("45");
+
+        // Scenario 4
+        executeIfFilePresent();
+
+        // Scenario 5
+        Point point = new Point(7, 3);
+        if (point instanceof Point(int x, _)) {
+            // Only use the 'x' property from the Point record
+            System.out.printf("Point object with value of x: %d%n", x);
+        }
+    }
+
+    public static int countWords(Iterable<String> words) {
+        int totalWords = 0;
+        for (String _ : words) {
+            totalWords++;
+        }
+        return totalWords;
+    }
+
+    public static boolean convertAndDisplay(String input) {
+        boolean isValid;
+        try{
+            int _ = Integer.parseInt(input);
+            isValid = true;
+        }catch (NumberFormatException _) {
+            System.out.println("NumberFormatException due to invalid input: " + input);
+            isValid = false;
+        }catch (Exception _) {
+            System.out.println("Exception due to invalid input: " + input);
+            isValid = false;
+        }
+        return isValid;
+    }
+
+    public static void executeIfFilePresent() {
+        String filePath = "example.txt";
+        try(BufferedReader _ = new BufferedReader(new FileReader(filePath));){
+            System.out.println("Executing some logic");
+        } catch (FileNotFoundException _) {
+            System.out.println("FileNotFoundException");
+        } catch (IOException _) {
+            System.out.println("IOException");
+        }
+    }
+
+}
+
+record Point(int x, int y) { }
+
diff --git a/section29/src/com/eazybytes/java22/Vehicle.java b/section29/src/com/eazybytes/java22/Vehicle.java
@@ -0,0 +1,41 @@
+package com.eazybytes.java22;
+
+public sealed interface Vehicle permits Car, Bike, Truck {
+
+}
+
+final class Bike implements Vehicle {
+    private final String brand;
+
+    public Bike(String brand) {
+        this.brand = brand;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+}
+
+final class Car implements Vehicle {
+    private final String model;
+
+    public Car(String model) {
+        this.model = model;
+    }
+
+    public String getModel() {
+        return model;
+    }
+}
+
+final class Truck implements Vehicle {
+    private final String manufacturer;
+
+    public Truck(String manufacturer) {
+        this.manufacturer = manufacturer;
+    }
+
+    public String getManufacturer() {
+        return manufacturer;
+    }
+}
