Add toString() to IpAddressMatcher.java

Closes gh-16795

Author: su

web/src/main/java/org/springframework/security/web/util/matcher/IpAddressMatcher.java

@@ -130,4 +130,11 @@ private InetAddress parseAddress(String address) {
 		}
 	}
 
+	@Override
+	public String toString() {
+		String hostAddress = this.requiredAddress.getHostAddress();
+		return (this.nMaskBits < 0)
+				? "IpAddressMatcher[" + hostAddress + "]"
+				: "IpAddressMatcher[" + hostAddress + "/" + this.nMaskBits + "]";
+	}
 }

web/src/test/java/org/springframework/security/web/util/matcher/IpAddressMatcherTests.java

@@ -152,5 +152,24 @@ public void constructorWhenRequiredAddressIsEmptyThenThrowsIllegalArgumentExcept
 		assertThatIllegalArgumentException().isThrownBy(() -> new IpAddressMatcher(""))
 			.withMessage("ipAddress cannot be empty");
 	}
+	// gh-16795
+	@Test
+	public void toStringWhenCidrIsProvidedThenReturnsIpAddressWithCidr() {
+		IpAddressMatcher matcher = new IpAddressMatcher("192.168.1.0/24");
+
+		String result = matcher.toString();
+
+		assertThat(result).isEqualTo("IpAddressMatcher[192.168.1.0/24]");
+	}
+
+	// gh-16795
+	@Test
+	public void toStringWhenOnlyIpIsProvidedThenReturnsIpAddressOnly() {
+		IpAddressMatcher matcher = new IpAddressMatcher("127.0.0.1");
+
+		String result = matcher.toString();
+
+		assertThat(result).isEqualTo("IpAddressMatcher[127.0.0.1]");
+	}
 
 }