[OLINGO-328] improve AcceptType for multi value support

lib/commons-api/src/main/java/org/apache/olingo/commons/api/format/AcceptType.java

@@ -50,7 +50,7 @@ public class AcceptType {
   private static final String PARAMETER_Q = "q";
   private static final Pattern Q_PARAMETER_VALUE_PATTERN = Pattern.compile("1|0|1\\.0{1,3}|0\\.\\d{1,3}");
 
-  public static final AcceptType WILDCARD = create(MEDIA_TYPE_WILDCARD, MEDIA_TYPE_WILDCARD, null, 1F);
+  public static final AcceptType WILDCARD = create(MEDIA_TYPE_WILDCARD, MEDIA_TYPE_WILDCARD, createParameterMap(), 1F);
 
   private final String type;
   private final String subtype;
@@ -66,7 +66,7 @@ public class AcceptType {
     this.quality = quality;
   }
 
-  private TreeMap<String, String> createParameterMap() {
+  private static TreeMap<String, String> createParameterMap() {
     return new TreeMap<String, String>(new Comparator<String>() {
       @Override
       public int compare(final String o1, final String o2) {
@@ -123,11 +123,15 @@ public class AcceptType {
    * @return a new <code>AcceptType</code> object
    * @throws IllegalArgumentException if input string is not parseable
    */
-  public static AcceptType create(final String format) {
+  public static List<AcceptType> create(final String format) {
-    if (format == null) {
+    List<AcceptType> result = new ArrayList<AcceptType>();
-      throw new IllegalArgumentException("Parameter format MUST NOT be NULL.");
+    
+    String[] values = format.split(",");
+    for (String value : values) {
+      result.add(new AcceptType(value.trim()));
     }
-    return new AcceptType(format);
+    
+    return result;
   }
 
   /**
@@ -136,7 +140,7 @@ public class AcceptType {
    * @param format
    * @return a new <code>ContentType</code> object
    */
-  public static AcceptType parse(final String format) {
+  public static List<AcceptType> parse(final String format) {
     try {
       return AcceptType.create(format);
     } catch (IllegalArgumentException e) {
@@ -222,7 +226,7 @@ public class AcceptType {
   public static List<AcceptType> create(final List<String> acceptTypeStrings) {
     List<AcceptType> acceptTypes = new ArrayList<AcceptType>(acceptTypeStrings.size());
     for (String contentTypeString : acceptTypeStrings) {
-      acceptTypes.add(create(contentTypeString));
+      acceptTypes.addAll(create(contentTypeString));
     }
     return acceptTypes;
   }

lib/commons-api/src/test/java/org/apache/olingo/commons/api/format/AcceptTypeTest.java

@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.olingo.commons.api.format;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.junit.Test;
+
+public class AcceptTypeTest {
+
+  @Test
+  public void testMultiValueCreate() {
+    List<AcceptType>  atl = AcceptType.create("1/1,2/2 , 3/3 ");
+
+    assertEquals(3, atl.size());
+    assertEquals("1/1", atl.get(0).toString());
+    assertEquals("2/2", atl.get(1).toString());
+    assertEquals("3/3", atl.get(2).toString());
+  }
+  
+  @Test
+  public void testSingleValueCreate() {
+    List<AcceptType>  atl = AcceptType.create(" a/a ");
+
+    assertEquals(1, atl.size());
+    assertEquals("a/a", atl.get(0).toString());
+  }
+}