! fix ut fail: test logic distinguish java8- and java9+

Author: oldratlee

library/src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtilForJdk8Minus.java

@@ -179,29 +179,27 @@ private static boolean isDnsCacheEntryExpired(String host) {
 
     public static DnsCache listInetAddressCache()
             throws NoSuchFieldException, IllegalAccessException {
-
         final Map<String, Object> cache;
         final Map<String, Object> negativeCache;
         synchronized (getAddressCacheFieldOfInetAddress()) {
             cache = new HashMap<String, Object>(getCacheFiledOfAddressCacheFiledOfInetAddress());
             negativeCache = new HashMap<String, Object>(getCacheFiledOfNegativeCacheFiledOfInetAddress());
         }
 
-        List<DnsCacheEntry> retCache = new ArrayList<DnsCacheEntry>();
+        return new DnsCache(convert(cache), convert(negativeCache));
+    }
+
+    private static List<DnsCacheEntry> convert(Map<String, Object> cache) throws IllegalAccessException {
+        final List<DnsCacheEntry> ret = new ArrayList<DnsCacheEntry>();
         for (Map.Entry<String, Object> entry : cache.entrySet()) {
             final String host = entry.getKey();
-
             if (isDnsCacheEntryExpired(host)) { // exclude expired entries!
                 continue;
             }
-            retCache.add(inetAddress$CacheEntry2DnsCacheEntry(host, entry.getValue()));
-        }
-        List<DnsCacheEntry> retNegativeCache = new ArrayList<DnsCacheEntry>();
-        for (Map.Entry<String, Object> entry : negativeCache.entrySet()) {
-            final String host = entry.getKey();
-            retNegativeCache.add(inetAddress$CacheEntry2DnsCacheEntry(host, entry.getValue()));
+
+            ret.add(inetAddress$CacheEntry2DnsCacheEntry(host, entry.getValue()));
         }
-        return new DnsCache(retCache, retNegativeCache);
+        return ret;
     }
 
 

library/src/test/java/com/alibaba/dcm/DnsCacheManipulatorTest.java

@@ -9,6 +9,7 @@
 import java.util.*;
 
 import static com.alibaba.dcm.Util.getIpByName;
+import static com.alibaba.dcm.internal.JavaVersionUtil.isJdkAtMost8;
 import static com.alibaba.dcm.internal.TestTimeUtil.NEVER_EXPIRATION_NANO_TIME_TO_TIME_MILLIS;
 import static java.lang.System.currentTimeMillis;
 import static java.lang.Thread.sleep;
@@ -326,7 +327,11 @@ public void test_setNegativeDnsCachePolicy() throws Exception {
         // 3. touch dns cache with external other host operation
         //////////////////////////////////////////////////
         getIpByName("bing.com");
-        assertEquals(0, DnsCacheManipulator.getWholeDnsCache().getNegativeCache().size());
+        if (isJdkAtMost8()) {
+            assertOnlyNegativeCache(tick, tick + 2020);
+        } else {
+            assertTrue(DnsCacheManipulator.getWholeDnsCache().getNegativeCache().isEmpty());
+        }
 
         //////////////////////////////////////////////////
         // 4. relookup
@@ -358,9 +363,12 @@ static void assertEqualsIgnoreHostCase(DnsCacheEntry expected, DnsCacheEntry act
 
         final long expectedExpiration = expected.getExpiration().getTime();
         final long actualExpiration = actual.getExpiration().getTime();
+
         if (expectedExpiration == Long.MAX_VALUE) {
-            // hard code test logic for jdk 9+
-            if (actualExpiration != Long.MAX_VALUE) {
+            if (isJdkAtMost8()) {
+                assertEquals(expectedExpiration, actualExpiration);
+            } else {
+                // hard code test logic for jdk 9+
                 assertEqualsWithTolerance(NEVER_EXPIRATION_NANO_TIME_TO_TIME_MILLIS, actualExpiration, 5);
             }
         } else {