fix flaky tests

[prathyushreddylpr]

Description

Fixed the flaky test extendedXmlJavaTypeAdapter and simpleXmlJavaTypeAdapter inside JAXBUtilsTest.java class.

cxf/rt/frontend/jaxrs/src/test/java/org/apache/cxf/jaxrs/utils/JAXBUtilsTest.java

Line 38 in 1a02ba3

public void simpleXmlJavaTypeAdapter() {

cxf/rt/frontend/jaxrs/src/test/java/org/apache/cxf/jaxrs/utils/JAXBUtilsTest.java

Line 43 in 1a02ba3

public void extendedXmlJavaTypeAdapter() {

Root Cause

The tests extendedXmlJavaTypeAdapter and simpleXmlJavaTypeAdapter have been reported flaky when run with the NonDex tool. The tests failed due to the non-deterministic ordering of fields returned by getDeclaredFields(). The getDeclaredFields() method returns an array of Field objects representing all the fields declared by a class or interface. In the above tests, it returned two values: one a private field named birthDate of type java.time.LocalDate and the other org.apache.cxf.jaxrs.utils.JAXBUtilsTest$CustomerDetailsWithExtendedAdapter.this$0. The second value represents a synthetic field generated by the Java compiler for the inner class CustomerDetailsWithExtendedAdapter. When an inner class accesses members of its enclosing class, Java creates a synthetic field (in this case, this$0) as a reference to the outer class (JAXBUtilsTest) which is not useful for the test.

Fix

To ensure the tests are not flaky due to the non-deterministic ordering of fields returned by getDeclaredFields(), we introduced a condition to filter out the fields(synthetic and final fields) that are not useful for the testing.

How this has been tested?

Java: openjdk version "17.0.8"
Maven: Apache Maven 3.6.3

1. Module build - Successful
   Command used -

mvn install -pl core -am -DskipTests

2. Regular test - Successful
   Commands used -

mvn -pl rt/frontend/jaxrs/ -Dtest=org.apache.cxf.jaxrs.utils.JAXBUtilsTest#extendedXmlJavaTypeAdapter

mvn -pl rt/frontend/jaxrs/ -Dtest=org.apache.cxf.jaxrs.utils.JAXBUtilsTest#simpleXmlJavaTypeAdapter

3. NonDex test - Failed
   Command used -

mvn -pl rt/frontend/jaxrs/ edu.illinois:nondex-maven-plugin:2.1.7-SNAPSHOT:nondex -Dtest=org.apache.cxf.jaxrs.utils.JAXBUtilsTest#extendedXmlJavaTypeAdapter

mvn -pl rt/frontend/jaxrs/ edu.illinois:nondex-maven-plugin:2.1.7-SNAPSHOT:nondex -Dtest=org.apache.cxf.jaxrs.utils.JAXBUtilsTest#simpleXmlJavaTypeAdapter

NonDex test passed after the fix.

[zzjas]

LGTM