[test] remove reflection direct usage from SimpleProducerConsumerTest…

….testActiveAndInActiveConsumerEntryCacheBehavior (apache#14128)

* [test] remove reflection direct usage from SimpleProducerConsumerTest.testActiveAndInActiveConsumerEntryCacheBehavior

* checkstyle

pulsar-broker/src/test/java/org/apache/pulsar/client/api/SimpleProducerConsumerTest.java

@@ -41,8 +41,6 @@
 import io.netty.buffer.Unpooled;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
 import java.nio.ByteBuffer;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -103,6 +101,7 @@
 import org.apache.pulsar.common.schema.SchemaType;
 import org.apache.pulsar.common.util.FutureUtil;
 import org.awaitility.Awaitility;
+import org.powermock.reflect.Whitebox;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.testng.Assert;
@@ -978,13 +977,8 @@ public void testActiveAndInActiveConsumerEntryCacheBehavior() throws Exception {
 
         PersistentTopic topicRef = (PersistentTopic) pulsar.getBrokerService().getTopicReference(topic).get();
         ManagedLedgerImpl ledger = (ManagedLedgerImpl) topicRef.getManagedLedger();
-        Field cacheField = ManagedLedgerImpl.class.getDeclaredField("entryCache");
-        cacheField.setAccessible(true);
-        Field modifiersField = Field.class.getDeclaredField("modifiers");
-        modifiersField.setAccessible(true);
-        modifiersField.setInt(cacheField, cacheField.getModifiers() & ~Modifier.FINAL);
-        EntryCacheImpl entryCache = spy((EntryCacheImpl) cacheField.get(ledger));
-        cacheField.set(ledger, entryCache);
+        EntryCacheImpl entryCache = spy((EntryCacheImpl) Whitebox.getInternalState(ledger, "entryCache"));
+        Whitebox.setInternalState(ledger, "entryCache", entryCache);
 
         Message<byte[]> msg;
         // 2. Produce messages