add Java Consumer examples

Author: fishercoder1534

src/main/java/javaConsumerInterfaceExamples/ConsumerInterfaceExample.java

@@ -0,0 +1,42 @@
+package javaConsumerInterfaceExamples;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class ConsumerInterfaceExample {
+    static void printMessage(String name) {
+        System.out.println("Hello " + name);
+    }
+
+    static void printValue(int val) {
+        System.out.println(val);
+    }
+
+    static void addList(List<Integer> list) {
+        // Return sum of list values
+        int result = list.stream()
+                .mapToInt(Integer::intValue)
+                .sum();
+        System.out.println("Sum of list values: " + result);
+    }
+
+    public static void main(String[] args) {
+        // Referring method to String type Consumer interface
+        Consumer<String> consumer1 = ConsumerInterfaceExample::printMessage;
+        consumer1.accept("John");   // Calling Consumer method
+        // Referring method to Integer type Consumer interface
+        Consumer<Integer> consumer2 = ConsumerInterfaceExample::printValue;
+        consumer2.accept(12);   // Calling Consumer method
+
+        // Creating a list and adding values
+        List<Integer> list = new ArrayList<>();
+        list.add(10);
+        list.add(20);
+        list.add(30);
+        list.add(40);
+        // Referring method to String type Consumer interface
+        Consumer<List<Integer>> consumer = ConsumerInterfaceExample::addList;
+        consumer.accept(list);  // Calling Consumer method
+    }
+}

src/main/java/javaConsumerInterfaceExamples/MainApp.java

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+package javaConsumerInterfaceExamples;
+
+import java.util.function.Consumer;
+
+public class MainApp {
+    public static void main(String... args) {
+        Consumer<String> print = x -> System.out.println(x);
+        print.accept("java 8 consumer interface");   // java
+    }
+}