feat(utils): method for getting build number from full mod version

src/main/java/org/auioc/mods/arnicalib/utils/java/VersionUtils.java

@@ -4,7 +4,6 @@
 import java.util.jar.Attributes;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import javax.annotation.Nullable;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.Marker;
 import org.auioc.mods.arnicalib.utils.LogUtil;
@@ -15,14 +14,15 @@ public class VersionUtils {
 
     private static final Pair<String, String> DEFAULT_VERSION_TUPLE = Pair.of("0", "0");
     private static final Pattern REVISION_NUMBER_PATTERN = Pattern.compile("(?<=rev\\.)[0-9a-fA-F]{7}");
+    private static final Pattern BUILD_NUMBER_PATTERN = Pattern.compile("(?<=build\\.)\\d+");
 
     public static String getMainVersion(Attributes attrs) {
         return attrs.getValue("Implementation-Version");
     }
 
     public static String getFullVersion(Attributes attrs, String modName) {
         String version = attrs.getValue(modName + "-Version");
-        if (getRevisionNumber(version) == null) {
+        if (getRevisionNumber(version).isEmpty()) {
             LOGGER.warn(MARKER, "The revision number of mod " + modName + " is null. If this is a manually built version you can ignore this message.");
         }
         return version;
@@ -44,13 +44,20 @@ public static Pair<String, String> getModVersion(Class<?> clazz) {
         return getModVersion(clazz, clazz.getSimpleName());
     }
 
-    @Nullable
     public static String getRevisionNumber(String fullVersion) {
         Matcher matcher = REVISION_NUMBER_PATTERN.matcher(fullVersion);
         if (matcher.find()) {
             return matcher.group();
         }
-        return null;
+        return "";
+    }
+
+    public static int getBuildNumber(String fullVersion) {
+        Matcher matcher = BUILD_NUMBER_PATTERN.matcher(fullVersion);
+        if (matcher.find()) {
+            return Integer.parseInt(matcher.group());
+        }
+        return 0;
     }
 
 }