Merge pull request #298 from Lixiongyou/master

Add SubnetAddressIterable & SubnetAddressIterator
apache · Oct 13, 2024 · e6db671 · e6db671
2 parents 42348a5 + a75f769
commit e6db671
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diff --git a/src/main/java/org/apache/commons/net/util/SubnetUtils.java b/src/main/java/org/apache/commons/net/util/SubnetUtils.java
@@ -16,6 +16,8 @@
  */
 package org.apache.commons.net.util;
 
+import java.util.Iterator;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -223,6 +225,54 @@ public String toString() {
         }
     }
 
+    /**
+     * Allows an object to be the target of the "for-each loop" statement for a SubnetInfo.
+     *
+     * @since 3.12.0
+     */
+    public static class SubnetAddressIterable implements Iterable<String> {
+
+        private final SubnetInfo subnetInfo;
+
+        public SubnetAddressIterable(final SubnetInfo subnetInfo) {
+            this.subnetInfo = subnetInfo;
+        }
+
+        @Override
+        public Iterator<String> iterator() {
+            return new SubnetAddressIterator(subnetInfo);
+        }
+    }
+
+    /**
+     * Iterates over a SubnetInfo.
+     *
+     * @since 3.12.0
+     */
+    public static class SubnetAddressIterator implements Iterator<String> {
+
+        private final SubnetInfo subnetInfo;
+
+        private final AtomicInteger currentAddress;
+
+        public SubnetAddressIterator(final SubnetInfo subnetInfo) {
+            this.subnetInfo = subnetInfo;
+            currentAddress = new AtomicInteger(subnetInfo.low());
+        }
+
+        @Override
+        public boolean hasNext() {
+            return subnetInfo.getAddressCount() > 0 && currentAddress.get() <= subnetInfo.high();
+        }
+
+        @Override
+        public String next() {
+            String address = subnetInfo.format(subnetInfo.toArray(currentAddress.get()));
+            currentAddress.incrementAndGet();
+            return address;
+        }
+    }
+
     private static final String IP_ADDRESS = "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})";
     private static final String SLASH_FORMAT = IP_ADDRESS + "/(\\d{1,2})"; // 0 -> 32
     private static final Pattern ADDRESS_PATTERN = Pattern.compile(IP_ADDRESS);

diff --git a/src/test/java/org/apache/commons/net/SubnetUtilsTest.java b/src/test/java/org/apache/commons/net/SubnetUtilsTest.java
@@ -29,6 +29,9 @@
 import org.apache.commons.net.util.SubnetUtils.SubnetInfo;
 import org.junit.jupiter.api.Test;
 
+import java.util.ArrayList;
+import java.util.List;
+
 @SuppressWarnings("deprecation") // deliberate use of deprecated methods
 public class SubnetUtilsTest {
 
@@ -407,6 +410,21 @@ public void testParseSimpleNetmaskInclusive() {
         }
     }
 
+    @Test
+    public void testSubnetAddressIterable() {
+        SubnetUtils utils = new SubnetUtils("192.168.1.0/24");
+        List<String> addressList = new ArrayList<>();
+        for (String address : new SubnetUtils.SubnetAddressIterable(utils.getInfo())) {
+            addressList.add(address);
+        }
+        assertEquals(254, addressList.size());
+        assertFalse(addressList.contains("192.168.1.0"));
+        assertTrue(addressList.contains("192.168.1.1"));
+        assertTrue(addressList.contains("192.168.1.127"));
+        assertTrue(addressList.contains("192.168.1.254"));
+        assertFalse(addressList.contains("192.168.1.255"));
+    }
+
     @Test
     public void testPrevious() {
         final SubnetUtils utils = new SubnetUtils("192.168.0.1/29");