From c4431dadf5366c7fae40c26209331337f46f132b Mon Sep 17 00:00:00 2001
From: Deboshree <deboshree.banerjee@cred.club>
Date: Thu, 18 May 2023 19:27:02 +0530
Subject: [PATCH] change return type to optional

---
 .../stringtoint/StringToIntConverter.java     | 28 ++++++++-----------
 .../StringToIntConverterUnitTest.java         | 24 ++++++++--------
 2 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/core-java-modules/core-java-string-conversions-3/src/main/java/com/baeldung/stringtoint/StringToIntConverter.java b/core-java-modules/core-java-string-conversions-3/src/main/java/com/baeldung/stringtoint/StringToIntConverter.java
index 52d227c379..6e7ea05bd7 100644
--- a/core-java-modules/core-java-string-conversions-3/src/main/java/com/baeldung/stringtoint/StringToIntConverter.java
+++ b/core-java-modules/core-java-string-conversions-3/src/main/java/com/baeldung/stringtoint/StringToIntConverter.java
@@ -4,38 +4,34 @@ import java.util.Optional;
 import org.apache.commons.lang3.math.NumberUtils;
 
 public class StringToIntConverter {
-
-    private StringToIntConverter() {
-    }
-
-    public static Integer convertStringToIntUsingIntegerParseInt(String input){
+    Optional<Integer> convertStringToIntUsingIntegerParseInt(String input){
         try {
-            return Integer.parseInt(input);
+            return Optional.of(Integer.parseInt(input));
         } catch (NumberFormatException e) {
             // log or handle the error
-            return Integer.MIN_VALUE;
+            return Optional.empty();
         }
     }
 
-    public static Integer convertStringToIntUsingIntegerValueOf(String input){
+    Optional<Integer> convertStringToIntUsingIntegerValueOf(String input){
         try {
-            return Integer.valueOf(input);
+            return Optional.of(Integer.valueOf(input));
         } catch (NumberFormatException e) {
             // log or handle the error
-            return Integer.MIN_VALUE;
+            return Optional.empty();
         }
     }
 
-    public static Integer convertStringToIntUsingIntegerDecode(String input){
+    Optional<Integer> convertStringToIntUsingIntegerDecode(String input){
         try {
-            return Integer.decode(input);
+            return Optional.of(Integer.decode(input));
         } catch (Exception e) {
             // log or handle the error
-            return Integer.MIN_VALUE;
+            return Optional.empty();
         }
     }
 
-    public static Integer convertStringToIntUsingOptional(String input){
+    Optional<Integer> convertStringToIntUsingOptional(String input){
         Optional<Integer> parsedInt;
         try {
             parsedInt = Optional.of(Integer.parseInt(input));
@@ -43,10 +39,10 @@ public class StringToIntConverter {
             // log or handle the error
             parsedInt = Optional.empty();
         }
-        return parsedInt.orElse(Integer.MIN_VALUE);
+        return parsedInt;
     }
 
-    public static int convertStringToIntUsingNumberUtils(String input, Integer defaultValue){
+    int convertStringToIntUsingNumberUtils(String input, Integer defaultValue){
         return NumberUtils.toInt(input, defaultValue);
     }
 }
diff --git a/core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringtoint/StringToIntConverterUnitTest.java b/core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringtoint/StringToIntConverterUnitTest.java
index 1bd7450914..c0c5da7731 100644
--- a/core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringtoint/StringToIntConverterUnitTest.java
+++ b/core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringtoint/StringToIntConverterUnitTest.java
@@ -5,7 +5,9 @@ import java.util.List;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-class StringToIntConverterUnitTest {
+class stringToIntConverter {
+    
+    private StringToIntConverter stringToIntConverter = new StringToIntConverter();
 
     @Test
     void whenConvertingIntToString_thenInvalidCasesReturnIntegerMinValue() {
@@ -18,11 +20,11 @@ class StringToIntConverterUnitTest {
                 new TestData("hello", Integer.MIN_VALUE)
         );
         testData.forEach(data -> {
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerParseInt(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerValueOf(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingOptional(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerDecode(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingNumberUtils(data.input,Integer.MIN_VALUE ));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerParseInt(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerValueOf(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingOptional(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerDecode(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingNumberUtils(data.input,Integer.MIN_VALUE ));
         });
     }
 
@@ -33,11 +35,11 @@ class StringToIntConverterUnitTest {
                 new TestData("-23", -23)
         );
         testData.forEach(data -> {
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerParseInt(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerValueOf(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingOptional(data.input));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingNumberUtils(data.input, Integer.MIN_VALUE));
-            Assertions.assertEquals(data.expectedOutput, StringToIntConverter.convertStringToIntUsingIntegerDecode(data.input));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerParseInt(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerValueOf(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingOptional(data.input).orElse(Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingNumberUtils(data.input, Integer.MIN_VALUE));
+            Assertions.assertEquals(data.expectedOutput, stringToIntConverter.convertStringToIntUsingIntegerDecode(data.input).orElse(Integer.MIN_VALUE));
         });
     }