PBLEID-23771: replace System.out.print with proper log statement (#15)

pom.xml

@@ -14,6 +14,7 @@
         <junit-jupiter-version>5.9.1</junit-jupiter-version>
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
+        <slf4j.version>2.0.6</slf4j.version>
     </properties>
 
     <dependencies>
@@ -23,6 +24,11 @@
             <version>${idporten-validators-version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>${slf4j.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>

src/main/java/no/idporten/test/generate/fnr/SyntheticFodselsnummerGenerator.java

@@ -1,5 +1,8 @@
 package no.idporten.test.generate.fnr;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.time.LocalDate;
 import java.time.Year;
 import java.time.YearMonth;
@@ -10,6 +13,7 @@
 import java.util.Random;
 
 public class SyntheticFodselsnummerGenerator {
+    private static final Logger log = LoggerFactory.getLogger(SyntheticFodselsnummerGenerator.class);
     final int ILLEGAL_CHECKSUM_VALUE = 10;
 
 
@@ -38,7 +42,7 @@ private String generateValidFodselsnummer(final int year) {
         try {
             return generateFodselsnummer(year);
         } catch (RuntimeException e) {
-            System.out.println("Try regenerate, but failed: " + e.getMessage());
+            log.debug("Try regenerate, but failed: " + e.getMessage());
             return generateValidFodselsnummer(year);
         }
     }