XFF-10: Remove index file

* Create a core for XFF
* Add a folder explorer (to read files in the correct order)
* Create a XFF packager (create a ZIP with entries in the correct order)
* Rely more on NIO instead of IO

pom.xml

@@ -83,6 +83,7 @@
   </repositories>
 
   <modules>
+    <module>xff-core</module>
     <module>xff-filter-stream</module>
     <module>xff-rest-api</module>
   </modules>

xff-core/pom.xml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.xwiki.contrib</groupId>
+    <artifactId>xff</artifactId>
+    <version>0.3.2-SNAPSHOT</version>
+  </parent>
+  <artifactId>xff-core</artifactId>
+  <packaging>jar</packaging>
+  <name>XFF - Core</name>
+  <description>Core of the XFF packaging system which contains the model.</description>
+
+  <scm>
+    <connection>scm:git:git://github.com/xwiki-contrib/api-xff.git</connection>
+    <developerConnection>scm:git:git@github.com:xwiki-contrib/api-xff.git</developerConnection>
+    <url>https://github.com/xwiki-contrib/api-xff/tree/master/xff-core</url>
+    <tag>HEAD</tag>
+  </scm>
+
+  <properties>
+    <!-- Name to display by the Extension Manager -->
+    <xwiki.extension.name>XFF Core</xwiki.extension.name>
+  </properties>
+
+  <dependencies>
+    <!-- Test dependencies -->
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <!-- Apply the Checkstyle configurations defined in the top level pom.xml file -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>

xff-core/src/main/java/org/xwiki/xff/core/XFFExplorer.java

@@ -0,0 +1,123 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.xff.core;
+
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.xwiki.xff.core.model.XFF;
+
+/**
+ * This explorer will go through the folders of the package and provide interface to get the files in a correct order.
+ * 
+ * @version $Id$
+ * @since 7.1
+ */
+public class XFFExplorer extends SimpleFileVisitor<Path> implements Iterator<Path>, Iterable<Path>
+{
+    /**
+     * Root path to remind because XFF is only working with relative paths.
+     */
+    private Path rootPath;
+
+    /**
+     * List of paths of the XFF package (only referring to files).
+     */
+    private List<Path> paths;
+
+    /**
+     * Current index, used for the iterator.
+     */
+    private int index = -1;
+
+    /**
+     * Initialize the Walker by parsing the folder and ordering the files.
+     * 
+     * @param path is the root path where to look for a XFF package.
+     * @throws IOException whenever there is problems in reading files or walking through the folders.
+     */
+    public XFFExplorer(Path path) throws IOException
+    {
+        this.init(path);
+    }
+
+    private void init(Path path) throws IOException
+    {
+        this.rootPath = path;
+        this.paths = new ArrayList<Path>();
+        FileVisitor<Path> visitor = new SimpleFileVisitor<Path>()
+        {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException
+            {
+                paths.add(rootPath.relativize(file));
+                return FileVisitResult.CONTINUE;
+            }
+        };
+        Files.walkFileTree(path, visitor);
+        XFF xff = new XFF();
+        for (Path p : this.paths) {
+            xff.store(p);
+        }
+        this.paths = xff.orderedPaths();
+    }
+
+    @Override
+    public boolean hasNext()
+    {
+        return index + 1 < this.paths.size();
+    }
+
+    @Override
+    public Path next()
+    {
+        this.index += 1;
+        return this.paths.get(this.index);
+    }
+
+    @Override
+    public Iterator<Path> iterator()
+    {
+        return this;
+    }
+
+    @Override
+    public void remove()
+    {
+        throw new UnsupportedOperationException("The XFF Walker does not implement the remove method");
+    }
+
+    /**
+     * Get the root path of the XFF package (a folder).
+     * 
+     * @return the root path of the XFF package
+     */
+    public Path getPath() {
+        return this.rootPath;
+    }
+}

xff-core/src/main/java/org/xwiki/xff/core/XFFZipper.java

@@ -0,0 +1,84 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.xff.core;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Create zip file out of a XFF folder structure.
+ * 
+ * @version $Id$
+ * @since 7.1
+ */
+public class XFFZipper
+{
+    /**
+     * To explore into XFF package.
+     */
+    private XFFExplorer packageExplorer;
+
+    /**
+     * Initialize the Walker by parsing the folder and ordering the files.
+     * 
+     * @param path is the root path where to look for a XFF package.
+     * @throws IOException whenever there is problems in reading files or walking through the folders.
+     */
+    public XFFZipper(Path path) throws IOException
+    {
+        this.packageExplorer = new XFFExplorer(path);
+    }
+
+    /**
+     * Create an XFF package from the folder.
+     * 
+     * @param path to the file you want to write the package into.
+     * @throws IOException if file path is incorrect or if there is problem to find files of the package.
+     * @throws URISyntaxException only if path is incorrect
+     */
+    public void xff(Path path) throws IOException, URISyntaxException
+    {
+        Map<String, String> options = new HashMap<>();
+        options.put("create", "true");
+        options.put("encoding", "UTF-8");
+        Path rootPath = this.packageExplorer.getPath();
+        URI xffURI = URI.create(String.format("jar:file:%s", path.toString()));
+        try (FileSystem xff = FileSystems.newFileSystem(xffURI, options)) {
+            for (Path p : this.packageExplorer) {
+                Path filePath = rootPath.resolve(p);
+                Path xffPath = xff.getPath(p.toString());
+                Path dirPath = xff.getPath(xffPath.subpath(0, xffPath.getNameCount() - 1).toString());
+                if (!Files.isDirectory(dirPath)) {
+                    Files.createDirectories(dirPath);
+                }
+                Files.copy(filePath, xffPath, StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.COPY_ATTRIBUTES);
+            }
+        }
+        // zos.close();
+    }
+}

xff-core/src/main/java/org/xwiki/xff/core/model/Attachment.java

@@ -0,0 +1,72 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.xff.core.model;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * Represent the structure of an attachment.
+ * 
+ * @version $Id$
+ * @since 7.1
+ */
+public class Attachment implements XElement
+{
+    /**
+     * Prefix used in the path for attachments.
+     */
+    public static final String ATTACHMENTS_HINT = "attachments";
+
+    /**
+     * List of paths for attachments.
+     */
+    private Set<String> attachments;
+
+    /**
+     * Empty constructors initializing attributes.
+     */
+    public Attachment()
+    {
+        this.attachments = new TreeSet<String>();
+    }
+
+    @Override
+    public void store(Path path)
+    {
+        if (path.getNameCount() == 1) {
+            this.attachments.add(path.toString());
+        }
+    }
+
+    @Override
+    public List<Path> orderedPaths()
+    {
+        List<Path> paths = new ArrayList<Path>();
+        for (String attachmentName : this.attachments) {
+            paths.add(Paths.get(attachmentName));
+        }
+        return paths;
+    }
+}