BAEL-5418 - Convert long to int type in Java (#8) (#11895)

java-numbers-4/pom.xml

@@ -25,6 +25,11 @@
             <version>${commons-lang3.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
     </dependencies>
 
     <build>

java-numbers-4/src/main/java/com/baeldung/convertLongToInt/ConvertLongToInt.java

@@ -0,0 +1,44 @@
+package com.baeldung.convertLongToInt;
+
+import java.math.BigDecimal;
+import java.util.Optional;
+import java.util.function.Function;
+
+import com.google.common.primitives.Ints;
+
+public class ConvertLongToInt {
+
+    static Function<Long, Integer> convert = val -> Optional.ofNullable(val)
+        .map(Long::intValue)
+        .orElse(null);
+
+    public static int longToIntCast(long number) {
+        return (int) number;
+    }
+
+    public static int longToIntJavaWithMath(long number) {
+        return Math.toIntExact(number);
+    }
+
+    public static int longToIntJavaWithLambda(long number) {
+        return convert.apply(number);
+    }
+
+    public static int longToIntBoxingValues(long number) {
+        return Long.valueOf(number)
+            .intValue();
+    }
+
+    public static int longToIntGuava(long number) {
+        return Ints.checkedCast(number);
+    }
+
+    public static int longToIntGuavaSaturated(long number) {
+        return Ints.saturatedCast(number);
+    }
+
+    public static int longToIntWithBigDecimal(long number) {
+        return new BigDecimal(number).intValueExact();
+    }
+
+}

java-numbers-4/src/test/java/com/baeldung/convertLongToInt/ConvertLongToIntUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.convertLongToInt;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class ConvertLongToIntUnitTest {
+
+    @Test
+    void longToInt() {
+        long number = 186762L;
+        int expected = 186762;
+
+        assertEquals(expected, ConvertLongToInt.longToIntCast(number));
+        assertEquals(expected, ConvertLongToInt.longToIntJavaWithMath(number));
+        assertEquals(expected, ConvertLongToInt.longToIntJavaWithLambda(number));
+        assertEquals(expected, ConvertLongToInt.longToIntBoxingValues(number));
+        assertEquals(expected, ConvertLongToInt.longToIntGuava(number));
+        assertEquals(expected, ConvertLongToInt.longToIntGuavaSaturated(number));
+        assertEquals(expected, ConvertLongToInt.longToIntWithBigDecimal(number));
+    }
+
+}