Github user aljoscha commented on a diff in the pull request:
https://github.com/apache/flink/pull/5097#discussion_r156088318
--- Diff:
flink-core/src/main/java/org/apache/flink/api/java/typeutils/TypeExtractionUtils.java
---
@@ -338,4 +340,78 @@ public static boolean hasSuperclass(Class<?> clazz,
String superClassName) {
}
return Object.class;
}
+
+ /**
+ * Count the number of all accessible fields in the current class that
are not
+ * declared static, transient, or final.
+ */
+ public static int countFieldsInClass(Class<?> clazz) {
+ int fieldCount = 0;
+ for (Field field : getAllDeclaredFields(clazz, true)) {
+ if (!Modifier.isStatic(field.getModifiers()) &&
!Modifier.isTransient(field.getModifiers()) &&
+
!Modifier.isFinal(field.getModifiers())) {
+ fieldCount++;
+ }
+ }
+ return fieldCount;
+ }
+
+ /**
+ * Returns the declared field with the given name in a class hierarchy.
The field might be private. Returns
+ * null if such a field does not exist.
+ */
+ public static Field getDeclaredField(Class<?> clazz, String name) {
+ for (Field field : getAllDeclaredFields(clazz, true)) {
+ if (field.getName().equals(name)) {
+ return field;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Recursively determine all declared fields that are not static,
transient, or final.
+ * This is required because class.getFields() is not returning fields
defined
+ * in parent classes.
+ *
+ * @param clazz class to be analyzed
+ * @param ignoreDuplicates if true, in case of duplicate field names
only the lowest one
+ * in a hierarchy will be returned; throws
an exception otherwise
+ * @return list of fields
+ */
+ public static List<Field> getAllDeclaredFields(Class<?> clazz, boolean
ignoreDuplicates) {
+ List<Field> result = new ArrayList<>();
+ while (clazz != null) {
+ Field[] fields = clazz.getDeclaredFields();
+ for (Field field : fields) {
+ if (Modifier.isStatic(field.getModifiers()) ||
Modifier.isTransient(field.getModifiers()) ||
+
Modifier.isFinal(field.getModifiers())) {
+ continue; // we have no use for
transient, static, or final fields
+ }
+ if (hasFieldWithSameName(field.getName(),
result)) {
--- End diff --
Isn't this simply `result.stream().anyMatch(f ->
f.getName().equals(field.getName()))`?
---
