#473 Refactoring Request-Line validation

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

@@ -27,12 +27,11 @@
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.util.Iterator;
-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.Href;
+import org.takes.rq.RqRequestLine.Token;
 
 /**
  * HTTP URI query parsing.
@@ -63,15 +62,6 @@ public interface RqHref extends Request {
     @EqualsAndHashCode(callSuper = true)
     final class Base extends RqWrap implements RqHref {
 
-        /**
-         * HTTP Request-Line pattern.
-         * @see <a href="http://www
-         * .w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1">RFC 2616</a>
-         */
-        private static final Pattern REQUEST_PATTERN = Pattern.compile(
-            "([!-~]+) ([^ ]+)( [^ ]+)?"
-        );
-
         /**
          * Ctor.
          * @param req Original request
@@ -80,28 +70,10 @@ public Base(final Request req) {
             super(req);
         }
 
-        // @todo #445:30min/DEV RqMethod already validates Request-Line and
-        //  extracts HTTP Method from it. We should extract all important
-        //  information from Request-Line (HTTP method, URI and HTTP version)
-        //  in one place to enforce DRY principle.
         @Override
         public Href href() throws IOException {
-            if (!this.head().iterator().hasNext()) {
-                throw new HttpException(
-                    HttpURLConnection.HTTP_BAD_REQUEST,
-                    "HTTP Request should have Request-Line"
-                );
-            }
-            final String line = this.head().iterator().next();
-            final Matcher matcher =
-                REQUEST_PATTERN.matcher(line);
-            if (!matcher.matches()) {
-                throw new HttpException(
-                    HttpURLConnection.HTTP_BAD_REQUEST,
-                    String.format("Illegal Request-Line: %s", line)
-                );
-            }
-            final String uri = matcher.group(2);
+            final String uri = new RqRequestLine.Base(this)
+                .requestLineHeaderToken(Token.URI);
             return new Href(
                 String.format(
                     "http://%s%s",

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

@@ -25,10 +25,10 @@
 
 import java.io.IOException;
 import java.util.Locale;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import lombok.EqualsAndHashCode;
 import org.takes.Request;
+import org.takes.rq.RqRequestLine.Token;
 
 /**
  * HTTP method parsing.
@@ -112,14 +112,6 @@ final class Base extends RqWrap implements RqMethod {
             "[()<>@,;:\\\"/\\[\\]?={}]"
         );
 
-        /**
-         * HTTP method line pattern.
-         * [!-~] is for method or extension-method token (octets 33 - 126).
-         */
-        private static final Pattern PATTERN = Pattern.compile(
-            "([!-~]+) [^ ]+( [^ ]+){0,1}"
-        );
-
         /**
          * Ctor.
          * @param req Original request
@@ -130,14 +122,8 @@ public Base(final Request req) {
 
         @Override
         public String method() throws IOException {
-            final String line = this.head().iterator().next();
-            final Matcher matcher = PATTERN.matcher(line);
-            if (!matcher.matches()) {
-                throw new IOException(
-                    String.format("Invalid HTTP method line: %s", line)
-                );
-            }
-            final String method = matcher.group(1);
+            final String method = new RqRequestLine.Base(this)
+                .requestLineHeaderToken(Token.METHOD);
             if (SEPARATORS.matcher(method).find()) {
                 throw new IOException(
                     String.format("Invalid HTTP method: %s", method)

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

@@ -0,0 +1,181 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 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;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import lombok.EqualsAndHashCode;
+import org.takes.HttpException;
+import org.takes.Request;
+
+/**
+ * HTTP Request-Line parsing.
+ *
+ * <p>All implementations of this interface must be immutable and thread-safe.
+ *
+ * @author Vladimir Maksimenko (xupypr@xupypr.com)
+ * @version $Id$
+ * @since 0.29.1
+ */
+public interface RqRequestLine extends Request {
+
+    public static enum Token {
+        /**
+         * METHOD token.
+         */
+        METHOD(1),
+
+        /**
+         * URI token.
+         */
+        URI(2),
+
+        /**
+         * HTTPVERSION token.
+         */
+        HTTPVERSION(3);
+
+        /**
+         * Value.
+         */
+        private final int value;
+
+        /**
+         * Ctor.
+         * @param val Value
+         */
+        private Token(final int val) {
+            this.value = val;
+        }
+    }
+
+    /**
+     * Get Request-Line header.
+     * @return HTTP Request-Line header
+     * @throws IOException If fails
+     */
+    String requestLineHeader() throws IOException;
+
+    /**
+     * Get Request-Line header token.
+     * @param token Token
+     * @return HTTP Request-Line header token
+     * @throws IOException If fails
+     */
+    String requestLineHeaderToken(Token token) throws IOException;
+
+    /**
+     * Request decorator for Request-Line header validation
+     *
+     * <p>The class is immutable and thread-safe.
+     * @author Vladimir Maksimenko (xupypr@xupypr.com)
+     * @version $Id$
+     * @since 1.0
+     */
+    @EqualsAndHashCode(callSuper = true)
+    final class Base extends RqWrap implements RqRequestLine {
+        /**
+         * HTTP Request-line pattern.
+         * [!-~] is for method or extension-method token (octets 33 - 126).
+         * @see <a href="http://www
+         * .w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1">RFC 2616</a>
+         */
+        private static final Pattern PATTERN = Pattern.compile(
+            "([!-~]+) ([^ ]+)( [^ ]+)?"
+        );
+
+        /**
+         * Ctor.
+         * @param req Original request
+         */
+        public Base(final Request req) {
+            super(req);
+        }
+
+        @Override
+        public String requestLineHeader() throws IOException {
+            final String requestLine = this.getRequestLineHeader();
+            this.validateRequestLine(requestLine);
+            return requestLine;
+        }
+
+        @Override
+        public String requestLineHeaderToken(final Token token)
+            throws IOException {
+            final String requestLine = this.getRequestLineHeader();
+            final Matcher matcher = this.validateRequestLine(requestLine);
+            final String result = matcher.group(token.value);
+            if (result == null) {
+                throw new IllegalArgumentException(
+                    String.format(
+                        "There is no token %s in Request-Line header: %s",
+                        token.toString(),
+                        requestLine
+                    )
+                );
+            }
+            return result.trim();
+        }
+
+        /**
+         * Get Request-Line header.
+         *
+         * @return Valid Request-Line header
+         * @throws IOException If fails
+         */
+        private String getRequestLineHeader() throws IOException {
+            if (!this.head().iterator().hasNext()) {
+                throw new HttpException(
+                    HttpURLConnection.HTTP_BAD_REQUEST,
+                    "HTTP Request should have Request-Line"
+                );
+            }
+            return this.head().iterator().next();
+        }
+
+        /**
+         * Validate Request-Line according to PATTERN.
+         *
+         * @param requestline Request-Line header
+         * @return Matcher that can be used to extract tokens
+         * @throws HttpException If fails
+         */
+        private Matcher validateRequestLine(final String requestline)
+            throws HttpException {
+            final Matcher matcher = PATTERN.matcher(requestline);
+            if (!matcher.matches()) {
+                throw new HttpException(
+                    HttpURLConnection.HTTP_BAD_REQUEST,
+                    String.format(
+                        "Invalid HTTP Request-Line header: %s",
+                        requestline
+                    )
+                );
+            }
+            return matcher;
+        }
+    }
+}