Solved day 4 part 1

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2015'
-version '0.3.2'
+version '0.3.3'
 
 // Switch to gradle "all" distribution.
 wrapper {

day04/build.gradle

@@ -1,2 +1,3 @@
 dependencies {
+    implementation 'commons-codec:commons-codec:1.16.0'
 }

day04/src/main/java/de/havox_design/aoc2015/day04/AdventCoins.java

@@ -1,6 +1,7 @@
 package de.havox_design.aoc2015.day04;
 
 import de.havox_design.aoc2015.utils.DataReader;
+import org.apache.commons.codec.digest.DigestUtils;
 
 import java.util.List;
 
@@ -22,7 +23,16 @@ public static int solvePart2(String fileName) {
     }
 
     public int solvePart1() {
-        return 0;
+        for(int i = 0; i < Integer.MAX_VALUE; i++) {
+            String combinedKey = input + i;
+            String md5Hash = DigestUtils.md5Hex(combinedKey);
+
+            if(md5Hash.startsWith("00000")) {
+                return i;
+            }
+        }
+
+        throw new IllegalStateException("An valid hash should be able to be found.");
     }
 
     public int solvePart2() {

day04/src/test/java/de/havox_design/aoc2015/day04/Day04Test.java

@@ -18,8 +18,8 @@ void testMainClass() {
 
     @ParameterizedTest
     @MethodSource("getDataForPart1")
-    void testPart1(String fileName, int expectedHousesVisited) {
-        Assertions.assertEquals(expectedHousesVisited, AdventCoins.solvePart1(fileName));
+    void testPart1(String fileName, int expectedSecretNumber) {
+        Assertions.assertEquals(expectedSecretNumber, AdventCoins.solvePart1(fileName));
     }
 
     private static Stream<Arguments> getDataForPart1() {