src/com/andrew/apollo/lastfm/api/ResponseBuilder.java

   1 /*\r
   2  * Copyright (c) 2012, the Last.fm Java Project and Committers\r
   3  * All rights reserved.\r
   4  *\r
   5  * Redistribution and use of this software in source and binary forms, with or without modification, are\r
   6  * permitted provided that the following conditions are met:\r
   7  *\r
   8  * - Redistributions of source code must retain the above\r
   9  *   copyright notice, this list of conditions and the\r
  10  *   following disclaimer.\r
  11  *\r
  12  * - Redistributions in binary form must reproduce the above\r
  13  *   copyright notice, this list of conditions and the\r
  14  *   following disclaimer in the documentation and/or other\r
  15  *   materials provided with the distribution.\r
  16  *\r
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED\r
  18  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A\r
  19  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR\r
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT\r
  21  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS\r
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR\r
  23  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF\r
  24  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r
  25  */\r
  26 \r
  27 package com.andrew.apollo.lastfm.api;\r
  28 \r
  29 import java.util.ArrayList;\r
  30 import java.util.Collection;\r
  31 import java.util.Collections;\r
  32 \r
  33 import com.andrew.apollo.utils.DomElement;\r
  34 \r
  35 \r
  36 /**\r
  37  * This utility class can be used to generically generate Result objects (usually Lists or {@link PaginatedResult}s) from an XML response\r
  38  * using {@link ItemFactory ItemFactories}.\r
  39  *\r
  40  * @author Janni Kovacs\r
  41  */\r
  42 public final class ResponseBuilder {\r
  43 \r
  44         private ResponseBuilder() {\r
  45         }\r
  46 \r
  47         private static <T> ItemFactory<T> getItemFactory(Class<T> itemClass) {\r
  48                 return ItemFactoryBuilder.getFactoryBuilder().getItemFactory(itemClass);\r
  49         }\r
  50 \r
  51         public static <T> Collection<T> buildCollection(Result result, Class<T> itemClass) {\r
  52                 return buildCollection(result, getItemFactory(itemClass));\r
  53         }\r
  54 \r
  55         public static <T> Collection<T> buildCollection(Result result, ItemFactory<T> factory) {\r
  56                 if (!result.isSuccessful())\r
  57                         return Collections.emptyList();\r
  58                 return buildCollection(result.getContentElement(), factory);\r
  59         }\r
  60 \r
  61         public static <T> Collection<T> buildCollection(DomElement element, Class<T> itemClass) {\r
  62                 return buildCollection(element, getItemFactory(itemClass));\r
  63         }\r
  64 \r
  65         public static <T> Collection<T> buildCollection(DomElement element, ItemFactory<T> factory) {\r
  66                 if (element == null)\r
  67                         return Collections.emptyList();\r
  68                 Collection<DomElement> children = element.getChildren();\r
  69                 Collection<T> items = new ArrayList<T>(children.size());\r
  70                 for (DomElement child : children) {\r
  71                         items.add(factory.createItemFromElement(child));\r
  72                 }\r
  73                 return items;\r
  74         }\r
  75 \r
  76         public static <T> PaginatedResult<T> buildPaginatedResult(Result result, Class<T> itemClass) {\r
  77                 return buildPaginatedResult(result, getItemFactory(itemClass));\r
  78         }\r
  79 \r
  80         public static <T> PaginatedResult<T> buildPaginatedResult(Result result, ItemFactory<T> factory) {\r
  81                 if (!result.isSuccessful()) {\r
  82                         return new PaginatedResult<T>(0, 0, Collections.<T>emptyList());\r
  83                 }\r
  84 \r
  85                 DomElement contentElement = result.getContentElement();\r
  86                 return buildPaginatedResult(contentElement, contentElement, factory);\r
  87         }\r
  88 \r
  89         public static <T> PaginatedResult<T> buildPaginatedResult(DomElement contentElement, DomElement childElement, Class<T> itemClass) {\r
  90                 return buildPaginatedResult(contentElement, childElement, getItemFactory(itemClass));\r
  91         }\r
  92 \r
  93         public static <T> PaginatedResult<T> buildPaginatedResult(DomElement contentElement, DomElement childElement, ItemFactory<T> factory) {\r
  94                 Collection<T> items = buildCollection(childElement, factory);\r
  95 \r
  96                 String totalPagesAttribute = contentElement.getAttribute("totalPages");\r
  97                 if (totalPagesAttribute == null)\r
  98                         totalPagesAttribute = contentElement.getAttribute("totalpages");\r
  99 \r
 100                 int page = Integer.parseInt(contentElement.getAttribute("page"));\r
 101                 int totalPages = Integer.parseInt(totalPagesAttribute);\r
 102 \r
 103                 return new PaginatedResult<T>(page, totalPages, items);\r
 104         }\r
 105 \r
 106         public static <T> T buildItem(Result result, Class<T> itemClass) {\r
 107                 return buildItem(result, getItemFactory(itemClass));\r
 108         }\r
 109 \r
 110         public static <T> T buildItem(Result result, ItemFactory<T> factory) {\r
 111                 if (!result.isSuccessful())\r
 112                         return null;\r
 113                 return buildItem(result.getContentElement(), factory);\r
 114         }\r
 115 \r
 116         public static <T> T buildItem(DomElement element, Class<T> itemClass) {\r
 117                 return buildItem(element, getItemFactory(itemClass));\r
 118         }\r
 119 \r
 120         private static <T> T buildItem(DomElement element, ItemFactory<T> factory) {\r
 121                 return factory.createItemFromElement(element);\r
 122         }\r
 123 }\r