Add RegexProperty

pmd-core/src/main/java/net/sourceforge/pmd/properties/AbstractSingleValueProperty.java

@@ -24,10 +24,11 @@ import net.sourceforge.pmd.Rule;
     /**
      * Creates a single value property.
      *
-     * @param theName        Name of the property
-     * @param theDescription Description
-     * @param theUIOrder     UI order
-     * @param theDefault     Default value
+     * @param theName             Name of the property
+     * @param theDescription      Description
+     * @param theUIOrder          UI order
+     * @param theDefault          Default value
+     * @param isDefinedExternally Whether the property is defined in the XML (by a XPath rule) or not
      *
      * @throws IllegalArgumentException If name or description are empty, or UI order is negative.
      */

pmd-core/src/main/java/net/sourceforge/pmd/properties/PropertyTypeId.java

@@ -31,6 +31,8 @@ public enum PropertyTypeId {
     CHARACTER("Character", CharacterProperty.extractor(), ValueParserConstants.CHARACTER_PARSER),
     CHARACTER_LIST("List[Character]", CharacterMultiProperty.extractor(), ValueParserConstants.CHARACTER_PARSER),
 
+    REGEX("Regex", RegexProperty.extractor(), ValueParserConstants.REGEX_PARSER),
+
     INTEGER("Integer", IntegerProperty.extractor(), ValueParserConstants.INTEGER_PARSER),
     INTEGER_LIST("List[Integer]", IntegerMultiProperty.extractor(), ValueParserConstants.INTEGER_PARSER),
     LONG("Long", LongProperty.extractor(), ValueParserConstants.LONG_PARSER),

pmd-core/src/main/java/net/sourceforge/pmd/properties/RegexProperty.java

@@ -0,0 +1,85 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.properties;
+
+import java.util.regex.Pattern;
+
+import net.sourceforge.pmd.properties.builders.PropertyDescriptorBuilderConversionWrapper;
+import net.sourceforge.pmd.properties.builders.PropertyDescriptorBuilderConversionWrapper.SingleValue;
+import net.sourceforge.pmd.properties.builders.SingleValuePropertyBuilder;
+
+
+/**
+ * Property which has a regex pattern as a value.
+ *
+ * @author Clément Fournier
+ * @since 6.1.0
+ */
+public final class RegexProperty extends AbstractSingleValueProperty<Pattern> {
+
+    RegexProperty(String theName, String theDescription, Pattern theDefault, float theUIOrder, boolean isDefinedExternally) {
+        super(theName, theDescription, theDefault, theUIOrder, isDefinedExternally);
+    }
+
+
+    @Override
+    protected Pattern createFrom(String toParse) {
+        return Pattern.compile(toParse);
+    }
+
+
+    @Override
+    public Class<Pattern> type() {
+        return Pattern.class;
+    }
+
+
+    static SingleValue<Pattern, RegexPBuilder> extractor() {
+        return new PropertyDescriptorBuilderConversionWrapper.SingleValue<Pattern, RegexPBuilder>(Pattern.class, ValueParserConstants.REGEX_PARSER) {
+            @Override
+            protected RegexPBuilder newBuilder(String name) {
+                return new RegexPBuilder(name);
+            }
+        };
+    }
+
+
+    /**
+     * Creates a new builder for a regex property.
+     *
+     * @param name The name of the property
+     *
+     * @return A new builder
+     */
+    public static RegexPBuilder named(String name) {
+        return new RegexPBuilder(name);
+    }
+
+    /** Builder for a {@link RegexProperty}. */
+    public static final class RegexPBuilder extends SingleValuePropertyBuilder<Pattern, RegexProperty.RegexPBuilder> {
+        private RegexPBuilder(String name) {
+            super(name);
+        }
+
+
+        /**
+         * Specify a default pattern for the property.
+         * The string value must be a valid regex pattern.
+         *
+         * @param val Regex pattern
+         *
+         * @return The same builder
+         */
+        public RegexPBuilder defaultValue(String val) {
+            return super.defaultValue(Pattern.compile(val));
+        }
+
+
+        @Override
+        public RegexProperty build() {
+            return new RegexProperty(this.name, this.description, this.defaultValue, this.uiOrder, isDefinedInXML);
+        }
+    }
+}

pmd-core/src/main/java/net/sourceforge/pmd/properties/ValueParserConstants.java

@@ -14,6 +14,7 @@ import java.lang.reflect.Array;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Pattern;
 
 import org.apache.commons.lang3.StringUtils;
 
@@ -195,6 +196,14 @@ public final class ValueParserConstants {
         }
     };
 
+    /** Compiles a regex. */
+    static final ValueParser<Pattern> REGEX_PARSER = new ValueParser<Pattern>() {
+        @Override
+        public Pattern valueOf(String value) throws IllegalArgumentException {
+            return Pattern.compile(value);
+        }
+    };
+
     /** Extract classes. */
     static final ValueParser<Class> CLASS_PARSER = new ValueParser<Class>() {
         @Override