diff --git a/src/main/java/uk/org/iay/incommon/mda/validate/string/AcceptStringRegexValidator.java b/src/main/java/uk/org/iay/incommon/mda/validate/string/AcceptStringRegexValidator.java
index b6850cb..909e136 100644
--- a/src/main/java/uk/org/iay/incommon/mda/validate/string/AcceptStringRegexValidator.java
+++ b/src/main/java/uk/org/iay/incommon/mda/validate/string/AcceptStringRegexValidator.java
@@ -15,16 +15,11 @@
 package uk.org.iay.incommon.mda.validate.string;
 
 import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 import javax.annotation.Nonnull;
 
 import net.shibboleth.metadata.Item;
-import net.shibboleth.metadata.validate.BaseValidator;
 import net.shibboleth.metadata.validate.Validator;
-import net.shibboleth.utilities.java.support.annotation.constraint.NonnullAfterInit;
-import net.shibboleth.utilities.java.support.component.ComponentInitializationException;
-import net.shibboleth.utilities.java.support.component.ComponentSupport;
 
 /**
  * A <code>Validator</code> that accepts {@link String} values matching a regular expression.
@@ -32,56 +27,15 @@
  * This validator returns {@link net.shibboleth.metadata.validate.Validator.Action#DONE}
  * if the entire value is matched by the regular expression, thus terminating any validator sequence.
  */
-public class AcceptStringRegexValidator extends BaseValidator implements Validator<String> {
-
-    /** Regular expression to be accepted by this validator. */
-    @NonnullAfterInit
-    private String regex;
-
-    /** Compiled regular expression to use in match operations. */
-    @NonnullAfterInit
-    private Pattern pattern;
-
-    /**
-     * Returns the regular expression.
-     *
-     * @return Returns the regular expression.
-     */
-    @NonnullAfterInit
-    public String getRegex() {
-        return regex;
-    }
-
-    /**
-     * Sets the regular expression to be accepted.
-     *
-     * @param r the regular expression to set.
-     */
-    public void setRegex(@Nonnull final String r) {
-        ComponentSupport.ifDestroyedThrowDestroyedComponentException(this);
-        ComponentSupport.ifInitializedThrowUnmodifiabledComponentException(this);
-
-        regex = r;
-    }
+public class AcceptStringRegexValidator extends BaseStringRegexValidator implements Validator<String> {
 
     @Override
     public Action validate(@Nonnull final String e, @Nonnull final Item<?> item, @Nonnull final String stageId) {
-        final Matcher matcher = pattern.matcher(e);
+        final Matcher matcher = getPattern().matcher(e);
         if (matcher.matches()) {
             return Action.DONE;
         } else {
             return Action.CONTINUE;
         }
     }
-
-    @Override
-    protected void doInitialize() throws ComponentInitializationException {
-        super.doInitialize();
-
-        if (getRegex() == null) {
-            throw new ComponentInitializationException("regular expression to be matched can not be null");
-        }
-
-        pattern = Pattern.compile(regex);
-    }
 }
diff --git a/src/main/java/uk/org/iay/incommon/mda/validate/string/BaseStringRegexValidator.java b/src/main/java/uk/org/iay/incommon/mda/validate/string/BaseStringRegexValidator.java
new file mode 100644
index 0000000..234e858
--- /dev/null
+++ b/src/main/java/uk/org/iay/incommon/mda/validate/string/BaseStringRegexValidator.java
@@ -0,0 +1,81 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package uk.org.iay.incommon.mda.validate.string;
+
+import java.util.regex.Pattern;
+
+import javax.annotation.Nonnull;
+
+import net.shibboleth.metadata.validate.BaseValidator;
+import net.shibboleth.utilities.java.support.annotation.constraint.NonnullAfterInit;
+import net.shibboleth.utilities.java.support.component.ComponentInitializationException;
+import net.shibboleth.utilities.java.support.component.ComponentSupport;
+
+/**
+ * A base class for <code>Validator</code>s that match {@link String} values against a regular expression.
+ */
+public abstract class BaseStringRegexValidator extends BaseValidator {
+
+    /** Regular expression to be accepted by this validator. */
+    @NonnullAfterInit
+    private String regex;
+
+    /** Compiled regular expression to use in match operations. */
+    @NonnullAfterInit
+    private Pattern pattern;
+
+    /**
+     * Returns the regular expression.
+     *
+     * @return Returns the regular expression.
+     */
+    @NonnullAfterInit
+    public String getRegex() {
+        return regex;
+    }
+
+    /**
+     * Sets the regular expression to be accepted.
+     *
+     * @param r the regular expression to set.
+     */
+    public void setRegex(@Nonnull final String r) {
+        ComponentSupport.ifDestroyedThrowDestroyedComponentException(this);
+        ComponentSupport.ifInitializedThrowUnmodifiabledComponentException(this);
+
+        regex = r;
+    }
+
+    /**
+     * Get the compiled regular expression for use in matching.
+     *
+     * @return the compiled {@link Pattern}
+     */
+    protected Pattern getPattern() {
+        return pattern;
+    }
+
+    @Override
+    protected void doInitialize() throws ComponentInitializationException {
+        super.doInitialize();
+
+        if (getRegex() == null) {
+            throw new ComponentInitializationException("regular expression to be matched can not be null");
+        }
+
+        pattern = Pattern.compile(regex);
+    }
+
+}