hotfix: reduce size docker image file.

Dockerfile

@@ -1,3 +1,16 @@
+# Stage 1: Build custom Java runtime using jlink
+FROM eclipse-temurin:21 as jre-build
+
+# Create a custom Java runtime
+RUN $JAVA_HOME/bin/jlink \
+         --add-modules java.base \
+         --strip-debug \
+         --no-man-pages \
+         --no-header-files \
+         --compress=2 \
+         --output /javaruntime
+
+# Stage 2: Build the application
 FROM eclipse-temurin:21-jdk-alpine AS build
 
 RUN apk add --no-cache maven
@@ -7,15 +20,22 @@ COPY pom.xml /app
 
 WORKDIR /app
 RUN mvn clean package -DskipTests -U \
-    && rm -rf /root/.m2
+    && rm -rf /root/.m2 \
+    && rm -rf /app/src
 
-# Run stage
-FROM eclipse-temurin:21-jre-alpine
+# Stage 3: Create the final image with the custom Java runtime and application
+FROM debian:buster-slim
+ENV JAVA_HOME=/opt/java/openjdk
+ENV PATH="${JAVA_HOME}/bin:${PATH}"
+COPY --from=jre-build /javaruntime $JAVA_HOME
 
+# Copy the application JAR from the build stage
 WORKDIR /usr/src/app
 COPY --from=build /app/target/QualityLabPro-0.7.jar ./app.jar
 
+# Set environment variables
 ENV SPRING_PROFILES_ACTIVE=prod \
     SERVER_PORT=8080
 
-EXPOSE ${SERVER_PORT}
+# Expose the application port
+EXPOSE ${SERVER_PORT}

Dockerfile_OLD_2

@@ -0,0 +1,22 @@
+FROM eclipse-temurin:21-jdk-alpine AS build
+
+RUN apk add --no-cache maven
+
+COPY src /app/src
+COPY pom.xml /app
+
+WORKDIR /app
+RUN mvn clean package -DskipTests -U \
+    && rm -rf /root/.m2 \
+    && rm -rf /app/src
+
+# Run stage
+FROM eclipse-temurin:21-jre-alpine
+
+WORKDIR /usr/src/app
+COPY --from=build /app/target/QualityLabPro-0.7.jar ./app.jar
+
+ENV SPRING_PROFILES_ACTIVE=prod \
+    SERVER_PORT=8080
+
+EXPOSE ${SERVER_PORT}

src/main/java/leonardo/labutilities/qualitylabpro/utils/components/StringToLocalDateTimeConverter.java

@@ -14,6 +14,7 @@ public class StringToLocalDateTimeConverter implements Converter<String, LocalDa
             DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
 
     @Override
+    @NonNull
     public LocalDateTime convert(@NonNull String source) {
         return LocalDateTime.parse(source, FORMATTER);
     }