#666: Refactored the class RqMtBase to reduce the coupling

src/main/java/org/takes/rq/RqHeaders.java

@@ -181,6 +181,13 @@ final class Smart implements RqHeaders {
         public Smart(final RqHeaders req) {
             this.origin = req;
         }
+        /**
+         * Ctor.
+         * @param req Original request
+         */
+        public Smart(final Request req) {
+            this(new RqHeaders.Base(req));
+        }
         @Override
         public List<String> header(final CharSequence name)
             throws IOException {

src/main/java/org/takes/rq/multipart/RqMtBase.java

@@ -24,17 +24,17 @@
 package org.takes.rq.multipart;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.RandomAccessFile;
 import java.net.HttpURLConnection;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
-import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.StandardOpenOption;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -44,19 +44,13 @@
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import lombok.EqualsAndHashCode;
 import org.takes.HttpException;
 import org.takes.Request;
 import org.takes.misc.Sprintf;
-import org.takes.misc.Utf8String;
 import org.takes.misc.VerboseIterable;
-import org.takes.rq.RqGreedy;
 import org.takes.rq.RqHeaders;
 import org.takes.rq.RqLengthAware;
-import org.takes.rq.RqLive;
 import org.takes.rq.RqMultipart;
-import org.takes.rq.RqWithHeader;
-import org.takes.rq.TempInputStream;
 
 /**
  * Request decorator, that decodes FORM data from
@@ -75,16 +69,14 @@
  * @since 0.33
  * @see <a href="http://www.w3.org/TR/html401/interact/forms.html">
  *  Forms in HTML</a>
- * @checkstyle ClassDataAbstractionCouplingCheck (500 lines)
- * @see RqGreedy
- * @todo #651:30min This class is highly coupled, it should be refactored in
- *  order to be able to reduce the overall coupling of this class which will
- *  allow to remove the violations ClassDataAbstractionCouplingCheck and
- *  PMD.ExcessiveImports.
+ * @see org.takes.rq.RqGreedy
  */
-@SuppressWarnings("PMD.ExcessiveImports")
-@EqualsAndHashCode(of = "origin")
+@lombok.EqualsAndHashCode(of = "origin")
 public final class RqMtBase implements RqMultipart {
+    /**
+     * The encoding used to create the request.
+     */
+    private static final Charset ENCODING = Charset.forName("UTF-8");
     /**
      * Pattern to get boundary from header.
      */
@@ -179,9 +171,7 @@ public InputStream body() throws IOException {
      */
     private Map<String, List<Request>> requests(
         final Request req) throws IOException {
-        final String header = new RqHeaders.Smart(
-            new RqHeaders.Base(req)
-        ).single("Content-Type");
+        final String header = new RqHeaders.Smart(req).single("Content-Type");
         if (!header.toLowerCase(Locale.ENGLISH)
             .startsWith("multipart/form-data")) {
             throw new HttpException(
@@ -210,9 +200,9 @@ private Map<String, List<Request>> requests(
                 "failed to read the request body"
             );
         }
-        final byte[] boundary = new Utf8String(
-            String.format("%s--%s", RqMtBase.CRLF, matcher.group(1))
-        ).bytes();
+        final byte[] boundary = String.format(
+            "%s--%s", RqMtBase.CRLF, matcher.group(1)
+        ).getBytes(RqMtBase.ENCODING);
         this.buffer.flip();
         this.buffer.position(boundary.length - 2);
         final Collection<Request> requests = new LinkedList<>();
@@ -240,32 +230,23 @@ private Request make(final byte[] boundary,
         final File file = File.createTempFile(
             RqMultipart.class.getName(), ".tmp"
         );
-        final FileChannel channel = new RandomAccessFile(
-            file, "rw"
-        ).getChannel();
-        try {
+        try (WritableByteChannel channel = Files.newByteChannel(
+            file.toPath(),
+            StandardOpenOption.READ,
+            StandardOpenOption.WRITE
+        )
+        ) {
             channel.write(
                 ByteBuffer.wrap(
-                    new Utf8String(this.head().iterator().next()).bytes()
+                    this.head().iterator().next().getBytes(RqMtBase.ENCODING)
                 )
             );
             channel.write(
-                ByteBuffer.wrap(new Utf8String(RqMtBase.CRLF).bytes())
+                ByteBuffer.wrap(RqMtBase.CRLF.getBytes(RqMtBase.ENCODING))
             );
             this.copy(channel, boundary, body);
-        } finally {
-            channel.close();
         }
-        return new RqWithHeader(
-            new RqLive(
-                new TempInputStream(
-                    new FileInputStream(file),
-                    file
-                )
-            ),
-            "Content-Length",
-            String.valueOf(file.length())
-        );
+        return new RqTemp(file);
     }
     /**
      * Copy until boundary reached.
@@ -324,9 +305,8 @@ private static Map<String, List<Request>> asMap(
         final Collection<Request> reqs) throws IOException {
         final Map<String, List<Request>> map = new HashMap<>(reqs.size());
         for (final Request req : reqs) {
-            final String header = new RqHeaders.Smart(
-                new RqHeaders.Base(req)
-            ).single("Content-Disposition");
+            final String header =
+                new RqHeaders.Smart(req).single("Content-Disposition");
             final Matcher matcher = RqMtBase.NAME.matcher(header);
             if (!matcher.matches()) {
                 throw new HttpException(

src/main/java/org/takes/rq/multipart/RqTemp.java

@@ -0,0 +1,64 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2016 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.takes.rq.multipart;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import lombok.EqualsAndHashCode;
+import org.takes.rq.RqLive;
+import org.takes.rq.RqWithHeader;
+import org.takes.rq.RqWrap;
+import org.takes.rq.TempInputStream;
+
+/**
+ * Request with a temporary file as body. The temporary file will be deleted
+ * automatically when the body of the request will be closed.
+ * @author Nicolas Filotto (nicolas.filotto@gmail.com)
+ * @version $Id$
+ * @since 0.33
+ * @see org.takes.rq.RqLive
+ * @see org.takes.rq.TempInputStream
+ */
+@EqualsAndHashCode(callSuper = true)
+final class RqTemp extends RqWrap {
+
+    /**
+     * Creates a {@code RqTemp} with the specified temporary file.
+     * @param file The temporary that will be automatically deleted when the
+     *  body of the request will be closed.
+     * @throws IOException If fails
+     */
+    RqTemp(final File file) throws IOException {
+        super(
+            new RqWithHeader(
+                new RqLive(
+                    new TempInputStream(new FileInputStream(file), file)
+                ),
+                "Content-Length",
+                String.valueOf(file.length())
+            )
+        );
+    }
+}

src/test/java/org/takes/rq/multipart/RqTempTest.java

@@ -0,0 +1,73 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2016 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.takes.rq.multipart;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.Test;
+import org.takes.Request;
+
+/**
+ * Test case for {@link RqTemp}.
+ * @author Nicolas Filotto (nicolas.filotto@gmail.com)
+ * @version $Id$
+ * @since 0.33
+ */
+public final class RqTempTest {
+
+    /**
+     * RqTemp can delete the underlying temporary file.
+     * @throws IOException if some problem occurs.
+     */
+    @Test
+    public void deletesTempFile() throws IOException {
+        final File file = File.createTempFile(
+            RqTempTest.class.getName(),
+            ".tmp"
+        );
+        Files.write(
+            file.toPath(),
+            "Temp file deletion test".getBytes(StandardCharsets.UTF_8)
+        );
+        final Request request = new RqTemp(file);
+        try {
+            MatcherAssert.assertThat(
+                "File is not created!",
+                file.exists(),
+                Matchers.is(true)
+            );
+        } finally {
+            request.body().close();
+        }
+        MatcherAssert.assertThat(
+            "File exists after stream closure",
+            file.exists(),
+            Matchers.is(false)
+        );
+    }
+}