Jdk9doclet gradle (#261)

Hi,

I added the change to support gradle for the jdk9doclet to this seperate branch. Can this be integrated into master?

Kind regards,
Jules Houben

Author: juleshouben

spring-auto-restdocs-json-doclet-jdk9/src/main/java/capital/scalable/restdocs/jsondoclet/DirectoryLocationOption.java

@@ -0,0 +1,79 @@
+/*-
+ * #%L
+ * Spring Auto REST Docs Json Doclet for JDK9+
+ * %%
+ * Copyright (C) 2015 - 2018 Scalable Capital GmbH
+ * %%
+ * 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.
+ * #L%
+ */
+package capital.scalable.restdocs.jsondoclet;
+
+import jdk.javadoc.doclet.Doclet;
+
+import java.util.Arrays;
+import java.util.List;
+
+public abstract class DirectoryLocationOption implements Doclet.Option, Comparable<DirectoryLocationOption> {
+
+    private final String[] names;
+    private final String argumentName;
+    private final int argumentCount;
+    private final String description;
+    private final String parameters;
+
+    public DirectoryLocationOption() {
+        this.argumentName = "-d";
+        this.argumentCount = 1;
+        this.names = new String[]{argumentName};
+        this.description = "Directory location";
+        this.parameters = "-d";
+    }
+
+    @Override
+    public String getDescription() {
+        return description;
+    }
+
+    @Override
+    public Kind getKind() {
+        return Kind.STANDARD;
+    }
+
+    @Override
+    public List<String> getNames() {
+        return Arrays.asList(names);
+    }
+
+    @Override
+    public String getParameters() {
+        return parameters;
+    }
+
+    @Override
+    public String toString() {
+        return Arrays.toString(names);
+    }
+
+    @Override
+    public int getArgumentCount() {
+        return argumentCount;
+    }
+
+    @Override
+    public int compareTo(DirectoryLocationOption that) {
+        return this.getNames().get(0).compareTo(that.getNames().get(0));
+    }
+
+
+}

spring-auto-restdocs-json-doclet-jdk9/src/main/java/capital/scalable/restdocs/jsondoclet/ExtractDocumentationAsJsonDoclet.java

@@ -31,9 +31,11 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.*;
 
 import com.fasterxml.jackson.annotation.JsonAutoDetect;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import jdk.javadoc.doclet.Doclet;
 import jdk.javadoc.doclet.DocletEnvironment;
 import jdk.javadoc.doclet.StandardDoclet;
 
@@ -42,10 +44,12 @@
  */
 public class ExtractDocumentationAsJsonDoclet extends StandardDoclet {
 
+    private String directoryLocationPath;
+
+
     @Override
     public boolean run(DocletEnvironment docEnv) {
-
-        Path destinationDir = Paths.get("../generated-javadoc-json").toAbsolutePath();
+        Path destinationDir = getDestinationDir();
         ObjectMapper mapper = createObjectMapper();
 
         docEnv.getIncludedElements()
@@ -62,6 +66,30 @@ public boolean run(DocletEnvironment docEnv) {
         return true;
     }
 
+    private Path getDestinationDir() {
+        if (directoryLocationPath != null) {
+            return Paths.get(directoryLocationPath).toAbsolutePath();
+        } else {
+            return Paths.get("../generated-javadoc-json").toAbsolutePath();
+        }
+    }
+
+    @Override
+    public Set<Doclet.Option> getSupportedOptions() {
+        Set<Doclet.Option> result = new HashSet<>();
+
+        Doclet.Option directoryLocationOption = new DirectoryLocationOption() {
+            @Override
+            public boolean process(String opt, List<String> args) {
+                directoryLocationPath = args.get(0);
+                return true;
+            }
+        };
+        result.add(directoryLocationOption);
+        result.addAll(super.getSupportedOptions());
+        return result;
+    }
+
     private static PackageElement findPackageElement(Element classOrInterface) {
         Element pkg = classOrInterface.getEnclosingElement();
         int i = 10;
@@ -76,8 +104,8 @@ private static PackageElement findPackageElement(Element classOrInterface) {
     }
 
     private static void writeToFile(Path destinationDir, ObjectMapper mapper,
-            PackageElement packageElement, TypeElement classOrInterface,
-            ClassDocumentation cd) {
+                                    PackageElement packageElement, TypeElement classOrInterface,
+                                    ClassDocumentation cd) {
         try {
             Path path = path(destinationDir, packageElement, classOrInterface);
             try (BufferedWriter writer = Files.newBufferedWriter(path, UTF_8)) {
@@ -90,7 +118,7 @@ private static void writeToFile(Path destinationDir, ObjectMapper mapper,
     }
 
     private static Path path(Path destinationDir, PackageElement packageElement,
-            TypeElement classOrInterface) throws IOException {
+                             TypeElement classOrInterface) throws IOException {
         String packageName = packageElement.getQualifiedName().toString();
         String packageDir = packageName.replace(".", File.separator);
         Path packagePath = Paths.get(packageDir);