! fix "identical-code" issue in InetAddressCacheUtilForJava* #63

Author: oldratlee

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

@@ -2,6 +2,8 @@
 
 import sun.net.InetAddressCachePolicy;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import java.lang.reflect.Field;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
@@ -30,6 +32,17 @@ static InetAddress[] toInetAddressArray(String host, String[] ips) throws Unknow
         return addresses;
     }
 
+    @Nonnull
+    static String[] getIpFromInetAddress(@Nullable InetAddress[] inetAddresses) {
+        if (inetAddresses == null) return new String[0];
+
+        final String[] ips = new String[inetAddresses.length];
+        for (int i = 0; i < inetAddresses.length; i++) {
+            ips[i] = inetAddresses[i].getHostAddress();
+        }
+        return ips;
+    }
+
     /**
      * Set JVM DNS cache policy.
      *

library/src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtilForJava8Minus.java

@@ -15,8 +15,7 @@
 import java.util.List;
 import java.util.Map;
 
-import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.NEVER_EXPIRATION;
-import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.toInetAddressArray;
+import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.*;
 
 /**
  * Util class to manipulate dns cache for {@code JDK 8-}.
@@ -271,13 +270,11 @@ private static List<DnsCacheEntry> convert(Map<String, Object> cache) throws Ill
             }
         }
 
-        long expiration = expirationFieldOfInetAddress$CacheEntry.getLong(entry);
-        InetAddress[] addresses = (InetAddress[]) addressesFieldOfInetAddress$CacheEntry.get(entry);
+        final long expiration = expirationFieldOfInetAddress$CacheEntry.getLong(entry);
+
+        final InetAddress[] addresses = (InetAddress[]) addressesFieldOfInetAddress$CacheEntry.get(entry);
+        final String[] ips = getIpFromInetAddress(addresses);
 
-        String[] ips = new String[addresses.length];
-        for (int i = 0; i < addresses.length; i++) {
-            ips[i] = addresses[i].getHostAddress();
-        }
         return new DnsCacheEntry(host, ips, expiration);
     }
 

library/src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtilForJava9Plus.java

@@ -16,8 +16,7 @@
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ConcurrentSkipListSet;
 
-import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.NEVER_EXPIRATION;
-import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.toInetAddressArray;
+import static com.alibaba.dcm.internal.InetAddressCacheUtilCommons.*;
 import static com.alibaba.dcm.internal.TimeUtil.convertNanoTimeToTimeMillis;
 import static com.alibaba.dcm.internal.TimeUtil.getNanoTimeAfterMs;
 
@@ -272,32 +271,24 @@ public static DnsCache listInetAddressCache()
             }
         }
 
-        final InetAddress[] inetAddressArray;
+        final InetAddress[] inetAddresses;
         final long expiration;
         if (addressesClassName.equals(inetAddress$CachedAddresses_ClassName)) {
-            inetAddressArray = (InetAddress[]) inetAddressesFieldOfInetAddress$CacheAddress.get(addresses);
+            inetAddresses = (InetAddress[]) inetAddressesFieldOfInetAddress$CacheAddress.get(addresses);
 
             long expiryTimeNanos = expiryTimeFieldOfInetAddress$CacheAddress.getLong(addresses);
             expiration = convertNanoTimeToTimeMillis(expiryTimeNanos);
         } else if (addressesClassName.equals(inetAddress$NameServiceAddresses_ClassName)) {
             InetAddress inetAddress = (InetAddress) reqAddrFieldOfInetAddress$NameServiceAddress.get(addresses);
-            inetAddressArray = new InetAddress[]{inetAddress};
+            inetAddresses = new InetAddress[]{inetAddress};
 
             expiration = NEVER_EXPIRATION;
         } else {
             throw new IllegalStateException("JDK add new child class " + addressesClassName +
                     " for class InetAddress.Addresses, report issue for dns-cache-manipulator lib!");
         }
 
-        final String[] ips;
-        if (inetAddressArray == null) {
-            ips = new String[0];
-        } else {
-            ips = new String[inetAddressArray.length];
-            for (int i = 0; i < inetAddressArray.length; i++) {
-                ips[i] = inetAddressArray[i].getHostAddress();
-            }
-        }
+        final String[] ips = getIpFromInetAddress(inetAddresses);
 
         return new DnsCacheEntry(host, ips, expiration);
     }