Fix #3450: Cast to String for specific annotations in CRD Generator

When looping through annotated fields/methods, the current code assumes a `String` type `value` attribute. This fails with a `ClassCastException` if any annotation uses a different type.

`JsonSchemaTest` fails with a
```
java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String
```
error without the fix; passes with the fix.

Fixes #3450

CHANGELOG.md

@@ -14,6 +14,7 @@
 
 #### Bugs
 * Fix: Extension annotator doesn't generate XxxEditable classes
+* Fix #3450: CRD generator fails with ClassCastException in some cases
 
 #### Dependency Upgrade
 * Fix #3438: Upgrade Sundrio to 0.50.1

crd-generator/api/src/main/java/io/fabric8/crd/generator/AbstractJsonSchema.java

@@ -190,19 +190,20 @@ static PropertyOrAccessor fromMethod(Method method, String propertyName) {
 
     public void process() {
       annotations.forEach(a -> {
-        final String fromAnnotation = (String) a.getParameters().get("value");
         switch (a.getClassRef().getFullyQualifiedName()) {
           case ANNOTATION_NOT_NULL:
             required = true;
             break;
           case ANNOTATION_JSON_PROPERTY:
-            if (!Strings.isNullOrEmpty(fromAnnotation) && !propertyName.equals(fromAnnotation)) {
-              renamedTo = fromAnnotation;
+            final String nameFromAnnotation = (String) a.getParameters().get("value");
+            if (!Strings.isNullOrEmpty(nameFromAnnotation) && !propertyName.equals(nameFromAnnotation)) {
+              renamedTo = nameFromAnnotation;
             }
             break;
           case ANNOTATION_JSON_PROPERTY_DESCRIPTION:
-            if (!Strings.isNullOrEmpty(fromAnnotation)) {
-              description = fromAnnotation;
+            final String descriptionFromAnnotation = (String) a.getParameters().get("value");
+            if (!Strings.isNullOrEmpty(descriptionFromAnnotation)) {
+              description = descriptionFromAnnotation;
             }
             break;
         }

crd-generator/api/src/test/java/io/fabric8/crd/example/annotated/AnnotatedSpec.java

@@ -18,6 +18,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyDescription;
 
+import javax.validation.constraints.Min;
 import javax.validation.constraints.NotNull;
 
 public class AnnotatedSpec {
@@ -30,6 +31,8 @@ public class AnnotatedSpec {
   @NotNull
   private boolean emptySetter;
   private AnnotatedEnum anEnum;
+  @Min(0) // a non-string value attribute
+  private int sizedField;
 
   @JsonProperty("from-getter")
   @JsonPropertyDescription("from-getter-description")

crd-generator/api/src/test/java/io/fabric8/crd/generator/v1/JsonSchemaTest.java

@@ -75,7 +75,7 @@ void shouldAugmentPropertiesSchemaFromAnnotations() {
     assertEquals(2, properties.size());
     final JSONSchemaProps specSchema = properties.get("spec");
     Map<String, JSONSchemaProps> spec = specSchema.getProperties();
-    assertEquals(5, spec.size());
+    assertEquals(6, spec.size());
 
     // check descriptions are present
     assertTrue(spec.containsKey("from-field"));