replacing class Pattern

- use RE2J version of Pattern
- include dependency in POM

Author: rkeytacked

core/pom.xml

@@ -177,5 +177,10 @@
             <artifactId>handy-uri-templates</artifactId>
             <version>2.1.6</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.re2j</groupId>
+            <artifactId>re2j</artifactId>
+            <version>1.1</version>
+        </dependency>
     </dependencies>
 </project>

core/src/main/java/org/everit/json/schema/ObjectSchema.java

@@ -2,6 +2,7 @@
 
 import static java.util.Objects.requireNonNull;
 
+import com.google.re2j.Pattern;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -10,8 +11,6 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-import java.util.regex.Pattern;
-
 import org.everit.json.schema.internal.JSONPrinter;
 
 /**

core/src/main/java/org/everit/json/schema/ObjectSchemaValidatingVisitor.java

@@ -3,11 +3,10 @@
 import static java.lang.String.format;
 import static java.util.Objects.requireNonNull;
 
+import com.google.re2j.Pattern;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
-import java.util.regex.Pattern;
-
 import org.json.JSONObject;
 
 class ObjectSchemaValidatingVisitor extends Visitor {

core/src/main/java/org/everit/json/schema/StringSchema.java

@@ -3,9 +3,8 @@
 import static java.util.Objects.requireNonNull;
 import static org.everit.json.schema.FormatValidator.NONE;
 
+import com.google.re2j.Pattern;
 import java.util.Objects;
-import java.util.regex.Pattern;
-
 import org.everit.json.schema.internal.JSONPrinter;
 
 /**

core/src/main/java/org/everit/json/schema/StringSchemaValidatingVisitor.java

@@ -3,8 +3,8 @@
 import static java.lang.String.format;
 import static java.util.Objects.requireNonNull;
 
+import com.google.re2j.Pattern;
 import java.util.Optional;
-import java.util.regex.Pattern;
 
 public class StringSchemaValidatingVisitor extends Visitor {
 

core/src/main/java/org/everit/json/schema/Visitor.java

@@ -1,9 +1,9 @@
 package org.everit.json.schema;
 
+import com.google.re2j.Pattern;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.regex.Pattern;
 
 abstract class Visitor {