add ut for getWholeDnsCache

Author: oldratlee

src/main/java/com/alibaba/dcm/internal/InetAddressCacheUtil.java

@@ -201,6 +201,10 @@ public static DnsCache listInetAddressCache()
         List<DnsCacheEntry> retCache = new ArrayList<DnsCacheEntry>();
         for (Map.Entry<String, Object> entry : cache.entrySet()) {
             final String host = entry.getKey();
+
+            if ("0.0.0.0".equals(host) || host == null) { // exclude expired entries!
+                continue;
+            }
             retCache.add(inetAddress$CacheEntry2DnsCacheEntry(host, entry.getValue()));
         }
         List<DnsCacheEntry> retNegativeCache = new ArrayList<DnsCacheEntry>();

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

@@ -1,5 +1,6 @@
 package com.alibaba.dcm;
 
+import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -25,10 +26,11 @@ public class DnsCacheManipulatorTest {
 
     static final String DOMAIN_NOT_EXISTED = "www.domain-not-existed-7352jt-12559-AZ-7524087.com";
 
-    @BeforeClass
-    public static void beforeClass() throws Exception {
+    @Before
+    public void before() throws Exception {
         DnsCacheManipulator.clearDnsCache();
-        assertEquals(0, DnsCacheManipulator.getAllDnsCache().size());
+        assertTrue(DnsCacheManipulator.getAllDnsCache().isEmpty());
+        assertTrue(DnsCacheManipulator.getWholeDnsCache().getNegativeCache().isEmpty());
     }
 
     @Test
@@ -65,43 +67,51 @@ public void test_setDnsCache_getAllDnsCache() throws Exception {
                 new DnsCacheEntry(host.toLowerCase(), new String[]{IP3}, new Date(Long.MAX_VALUE)));
 
         assertEquals(expected, allDnsCacheEntries);
+        assertTrue(DnsCacheManipulator.getWholeDnsCache().getNegativeCache().isEmpty());
     }
 
     @Test
-    public void test_removeDnsCache() throws Exception {
-        final String notExistedHost = "www.not-existed-host-test_removeDnsCache";
+    public void test_canSetExistedDomain_canExpire_thenReLookupBack() throws Exception {
+        final String domain = "github.com";
+
+        final String ip = InetAddress.getByName(domain).getHostAddress();
+
+        DnsCacheManipulator.setDnsCache(30, domain, IP3);
+        assertEquals(IP3, InetAddress.getByName(domain).getHostAddress());
+
+        Thread.sleep(32);
+
+        assertEquals(ip, InetAddress.getByName(domain).getHostAddress());
+    }
 
-        DnsCacheManipulator.setDnsCache(notExistedHost, IP3);
-        final String ip = InetAddress.getByName(notExistedHost).getHostAddress();
+    @Test
+    public void test_canSetNotExistedDomain_RemoveThenReLookupAndNotExisted() throws Exception {
+        DnsCacheManipulator.setDnsCache(DOMAIN_NOT_EXISTED, IP3);
+        final String ip = InetAddress.getByName(DOMAIN_NOT_EXISTED).getHostAddress();
         assertEquals(IP3, ip);
 
-        DnsCacheManipulator.removeDnsCache(notExistedHost);
+        DnsCacheManipulator.removeDnsCache(DOMAIN_NOT_EXISTED);
 
         try {
-            InetAddress.getByName(notExistedHost).getHostAddress();
+            InetAddress.getByName(DOMAIN_NOT_EXISTED).getHostAddress();
             fail();
         } catch (UnknownHostException expected) {
             System.out.println(expected.toString());
             assertTrue(true);
         }
-    }
 
-    @Test
-    public void test_canResetExistedDomain_canExpire_thenReLookupBack() throws Exception {
-        final String domain = "github.com";
+        final List<DnsCacheEntry> cache = DnsCacheManipulator.listDnsCache();
+        System.out.println("test_canSetNotExistedDomain_RemoveThenReLookupAndNotExisted expired entries: " + cache);
+        assertTrue(cache.isEmpty());
 
-        final String ip = InetAddress.getByName(domain).getHostAddress();
-
-        DnsCacheManipulator.setDnsCache(30, domain, IP3);
-        assertEquals(IP3, InetAddress.getByName(domain).getHostAddress());
-
-        Thread.sleep(32);
-
-        assertEquals(ip, InetAddress.getByName(domain).getHostAddress());
+        final List<DnsCacheEntry> negativeCache = DnsCacheManipulator.getWholeDnsCache().getNegativeCache();
+        assertEquals(1, negativeCache.size());
+        System.out.println("test_canSetNotExistedDomain_RemoveThenReLookupAndNotExisted expired negative entries: " + negativeCache);
+        assertEquals(DOMAIN_NOT_EXISTED.toLowerCase(), negativeCache.get(0).getHost());
     }
 
     @Test
-    public void test_DnsCache_setNotExistedDomain_canExpire_thenReLookupAndNotExisted() throws Exception {
+    public void test_setNotExistedDomain_canExpire_thenReLookupAndNotExisted() throws Exception {
         DnsCacheManipulator.setDnsCache(30, DOMAIN_NOT_EXISTED, IP3);
         final String ip = InetAddress.getByName(DOMAIN_NOT_EXISTED).getHostAddress();
         assertEquals(IP3, ip);
@@ -115,6 +125,15 @@ public void test_DnsCache_setNotExistedDomain_canExpire_thenReLookupAndNotExiste
             System.out.println(expected.toString());
             assertTrue(true);
         }
+
+        final List<DnsCacheEntry> cache = DnsCacheManipulator.listDnsCache();
+        System.out.println("test_setNotExistedDomain_canExpire_thenReLookupAndNotExisted expired entries: " + cache);
+        assertTrue(cache.isEmpty());
+
+        final List<DnsCacheEntry> negativeCache = DnsCacheManipulator.getWholeDnsCache().getNegativeCache();
+        System.out.println("test_setNotExistedDomain_canExpire_thenReLookupAndNotExisted expired negative entries: " + negativeCache);
+        assertEquals(1, negativeCache.size());
+        assertEquals(DOMAIN_NOT_EXISTED.toLowerCase(), negativeCache.get(0).getHost());
     }
 
     @Test