在 Android 中存储静态数据 - 自定义资源？

Store static data in Android - custom resource?

提问by NickAldwin

I'm new to Android development, and I've been playing around with it a bit. I was trying to create a program that has a small database-like collection of never-changing data. In C#, my currently best language, I'd use a List of a custom class and serialize that to an xml file, then read that into my application at runtime. I found the /xml resource folder in Android, but I'm not sure how I would go about doing what I'm envisioning. What would be the best way to go about doing this?

我是 Android 开发的新手，我一直在玩它。我试图创建一个程序，该程序具有一个类似于数据库的小型永不更改数据集合。在 C# 中，我目前最好的语言，我会使用自定义类的列表并将其序列化为 xml 文件，然后在运行时将其读入我的应用程序。我在 Android 中找到了 /xml 资源文件夹，但我不确定我将如何去做我所设想的事情。这样做的最佳方法是什么？

The data will never need to change. Example:

数据永远不需要改变。例子：

Blob   | A  | B
----------------
Blob 1 | 23 | 42
Blob 2 | 34 | 21

I know that's laid out like a table, but using a database doesn't really make sense to me because the data will never change, and I would need a way to store it to initially populate the database anyway.

我知道这是奠定了像一个表，但使用一个数据库并没有真正意义的我，因为数据永远不会改变的，我需要一种方法来存储它最初填充数据库反正。

So basically I'm looking for a way to store somewhat-complex static data in my application. Any ideas?

所以基本上我正在寻找一种在我的应用程序中存储有点复杂的静态数据的方法。有任何想法吗？

EDIT: I also saw the /raw folder. So I could store things in /res/raw or /res/xml. But I'm not sure what would be the best way to store/parse the data...

编辑：我还看到了 /raw 文件夹。所以我可以将内容存储在 /res/raw 或 /res/xml 中。但我不确定存储/解析数据的最佳方式是什么......

采纳答案by CodeFusionMobile

The best way is to use the Android Resource Heirarchy.

最好的方法是使用Android Resource Heirarchy。

In the res/values/ directory, you can store any number of key-value pairs for several basic data types. In your app, you would refer to them using an autogenerated resource id (name based on your resource's key). See the link above for more documentation and details.

在 res/values/ 目录中，您可以为几种基本数据类型存储任意数量的键值对。在您的应用程序中，您将使用自动生成的资源 ID（基于您的资源键的名称）来引用它们。有关更多文档和详细信息，请参阅上面的链接。

Android also supports raw datafiles. You could store your data in the file directory under res/raw/yourfile.dat

Android 还支持原始数据文件。您可以将数据存储在 res/raw/yourfile.dat 下的文件目录中

You you create your data in whatever text based format you want and then read it on activity startup using the resource access apis.

您可以以任何您想要的基于文本的格式创建数据，然后在活动启动时使用资源访问 api 读取它。

回答by Paresh Mayani

I think this is the BEST solution and i am already using this one to store Static-data in my every project.

我认为这是最好的解决方案，我已经在使用这个解决方案在我的每个项目中存储静态数据。

For that... You can do one thing, make one xml file namely "temp.xml" ..and store the data in temp.xml as follows:

为此......你可以做一件事，制作一个xml文件，即“temp.xml”..并将数据存储在temp.xml中，如下所示：

  <?xml version="1.0" encoding="utf-8"?> 
<rootelement1>

    <subelement> Blob 1  
     <subsubelement> 23 </subsubelement>
     <subsubelement> 42 </subsubelement> 
    </subelement>

    <subelement>Blob 2      
    <subsubelement> 34 </subsubelement>
    <subsubelement> 21 </subsubelement>
    </subelement>


    </rootelement1>

and then use XML PullParsertechnique to parse data. You can have coding samples of PullParsing technique on Example , refer this example for better idea.

然后使用XML PullParser技术解析数据。您可以在Example上获得 PullParsing 技术的编码示例，请参阅此示例以获得更好的主意。

Enjoy!!

享受！！

回答by AlexIIP

I have used Simple for xml parsing in the past. I think it has the least amount of code if you know what to expect in xml, which in your case you do.

我过去曾使用 Simple 进行 xml 解析。如果您知道在 xml 中会发生什么，我认为它的代码量最少，在您的情况下，您就是这样做的。

http://simple.sourceforge.net/

http://simple.sourceforge.net/

回答by Balázs Lengyák

According to the doc, /xmlis the way to go.

根据doc，/xml是要走的路。

Providing Resources

提供资源

xml/Arbitrary XML files that can be read at run-time by calling

xml/可以在运行时通过调用读取的任意 XML 文件

Resources.getXML().

Various XML configuration files must be saved here, such as a searchable configuration.

此处必须保存各种 XML 配置文件，例如可搜索的配置。

Documentation for getXML()

文档 getXML()

I also made a working example:

我还做了一个工作示例：

• the XML structure:

  <?xml version="1.0" encoding="utf-8"?>
  <quizquestions>
      <quizquestion>
          <header_image_src>ic_help_black_24dp</header_image_src>
          <question>What is the Capital of U.S.A.?</question>
          <input_type>Radio</input_type>
          <answer correct="false">New York City</answer>
          <answer correct="true">Washington D.C.</answer>
          <answer correct="false">Chicago</answer>
          <answer correct="false">Philadelphia</answer>
      </quizquestion>
  
      <quizquestion>
          <header_image_src>ic_help_black_24dp</header_image_src>
          <question>What is the family name of the famous dutch painter Vincent Willem van .... ?</question>
          <input_type>EditText</input_type>              
          <answer correct="true">Gogh</answer>
      </quizquestion>
  </quizquestions>
  

• the Java class to hold parsed data:

  public class QuizQuestion {
      private int headerImageResId;
      private String question;
      private String inputType;
      private ArrayList<String> answers;
      private ArrayList<Boolean> answerIsCorrect;
      private ArrayList<Integer> correctAnswerIndexes;
  
      /**
       * constructor for QuizQuestion object
       */
      QuizQuestion() {
          headerImageResId = 0;
          question = null;
          inputType = null;
          answers = new ArrayList<>();
          answerIsCorrect = new ArrayList<>();
          correctAnswerIndexes = new ArrayList<>();
      }
  
  
      public void setHeaderImageResId(int headerImageResId) {
          this.headerImageResId = headerImageResId;
      }
  
      public int getHeaderImageResId() {
          return headerImageResId;
      }
  
  
      void setQuestion(String question) {
          this.question = question;
      }
  
      public String getQuestion() {
          return question;
      }
  
  
      void setInputType(String inputType) {
          this.inputType = inputType;
      }
  
      public String getInputType() {
          return inputType;
      }
  
      void addAnswer(String answer, boolean isCorrect)
      {
          if (isCorrect)
              correctAnswerIndexes.add(answers.size());
          answers.add(answer);
          answerIsCorrect.add(isCorrect);
      }
  
  
      public ArrayList<String> getAnswers() {
          return answers;
      }
  
      public String getAnswer(int index)
      {
          // check index to avoid out of bounds exception
          if (index < answers.size()) {
              return answers.get(index);
          }
          else
          {
              return null;
          }
      }
  
      public int size()
      {
          return answers.size();
      }
  
  }
  

• the parser itself:

  /**
   * Created by bivanbi on 2017.02.23..
   *
   * class to parse xml resource containing quiz data into ArrayList of QuizQuestion objects
   *
   */
  
  public class QuizXmlParser {
  
      public static String lastErrorMessage = "";
  
      /**
       * static method to parse XML data into ArrayList of QuizQuestion objects
       * @param activity is the calling activity
       * @param xmlResourceId is the resource id of XML resource to be parsed
       * @return null if parse error is occurred or ArrayList of objects if successful
       * @throws XmlPullParserException
       * @throws IOException
       */
      public static ArrayList<QuizQuestion> parse(Activity activity, int xmlResourceId)
              throws XmlPullParserException, IOException
      {
          String logTag = QuizXmlParser.class.getSimpleName();
          Resources res = activity.getResources();
          XmlResourceParser quizDataXmlParser = res.getXml(R.xml.quiz_data);
  
          ArrayList<String> xmlTagStack = new ArrayList<>();
          ArrayList<QuizQuestion> quizQuestions = new ArrayList<>();
  
          QuizQuestion currentQuestion = null;
  
          boolean isCurrentAnswerCorrect = false;
  
          quizDataXmlParser.next();
          int eventType = quizDataXmlParser.getEventType();
          while (eventType != XmlPullParser.END_DOCUMENT)
          {
              //  begin document
              if(eventType == XmlPullParser.START_DOCUMENT)
              {
                  Log.d(logTag,"Begin Document");
              }
              //  begin tag
              else if(eventType == XmlPullParser.START_TAG)
              {
                  String tagName = quizDataXmlParser.getName();
                  xmlTagStack.add(tagName);
                  Log.d(logTag,"Begin Tag "+tagName+", depth: "+xmlTagStack.size());
                  Log.d(logTag,"Tag "+tagName+" has "+quizDataXmlParser.getAttributeCount()+" attribute(s)");
  
                  // this is a beginning of a quiz question tag so create a new QuizQuestion object
                  if (tagName.equals("quizquestion")){
                      currentQuestion = new QuizQuestion();
                  }
                  else if(tagName.equals("answer"))
                  {
                      isCurrentAnswerCorrect = quizDataXmlParser.getAttributeBooleanValue(null,"correct",false);
                      if (isCurrentAnswerCorrect == true) {
                          Log.d(logTag, "Tag " + tagName + " has attribute correct = true");
                      }
                      else
                      {
                          Log.d(logTag, "Tag " + tagName + " has attribute correct = false");
                      }
                  }
              }
              //  end tag
              else if(eventType == XmlPullParser.END_TAG)
              {
                  String tagName = quizDataXmlParser.getName();
                  if (xmlTagStack.size() < 1)
                  {
                      lastErrorMessage = "Error 101: encountered END_TAG "+quizDataXmlParser.getName()+" while TagStack is empty";
                      Log.e(logTag, lastErrorMessage);
                      return null;
                  }
                  xmlTagStack.remove(xmlTagStack.size()-1);
                  Log.d(logTag,"End Tag "+quizDataXmlParser.getName()+", depth: "+xmlTagStack.size());
  
                  //  reached the end of a quizquestion definition, add it to the array
                  if (tagName.equals("quizquestion")){
                      if (currentQuestion != null)
                          quizQuestions.add(currentQuestion);
                      currentQuestion = null;
                  }
              }
              //  text between tag begin and end
              else if(eventType == XmlPullParser.TEXT)
              {
                  String currentTag = xmlTagStack.get(xmlTagStack.size()-1);
                  String text = quizDataXmlParser.getText();
                  Log.d(logTag,"Text: "+text+", current tag: "+currentTag+", depth: "+xmlTagStack.size());
  
                  if (currentQuestion == null) {
                      Log.e(logTag,"currentQuestion is not initialized! text: "+text+", current tag: "+currentTag+", depth: "+xmlTagStack.size());
                      continue;
                  }
  
                  if (currentTag.equals("header_image_src"))
                  {
                      int drawableResourceId = activity.getResources().getIdentifier(text, "drawable", activity.getPackageName());
                      currentQuestion.setHeaderImageResId(drawableResourceId);
                  }
                  else if (currentTag.equals("question"))
                  {
                      currentQuestion.setQuestion(text);
                  }
                  else if (currentTag.equals("answer"))
                  {
                      currentQuestion.addAnswer(text, isCurrentAnswerCorrect);
                  }
                  else if (currentTag.equals("input_type"))
                  {
                      currentQuestion.setInputType(text);
                  }
                  else
                  {
                      Log.e(logTag,"Unexpected tag "+currentTag+" with text: "+text+", depth: "+xmlTagStack.size());
                  }
              }
              eventType = quizDataXmlParser.next();
          }
          Log.d(logTag,"End Document");
          return quizQuestions;
      }
  
  }
  

• and finally, calling the parser:

  //  read quiz data from xml resource quiz_data
  try {
      quizQuestions = QuizXmlParser.parse(this,R.xml.quiz_data);
      Log.d("Main","QuizQuestions: "+quizQuestions);
  
  } catch (XmlPullParserException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      quizQuestions = null;
  } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      quizQuestions = null;
  }
  
  if (quizQuestions == null)
  {
      Toast.makeText(this,"1001 Failed to parse Quiz XML, sorry", Toast.LENGTH_LONG).show();
      finish();
  }
  

• XML 结构：

  <?xml version="1.0" encoding="utf-8"?>
  <quizquestions>
      <quizquestion>
          <header_image_src>ic_help_black_24dp</header_image_src>
          <question>What is the Capital of U.S.A.?</question>
          <input_type>Radio</input_type>
          <answer correct="false">New York City</answer>
          <answer correct="true">Washington D.C.</answer>
          <answer correct="false">Chicago</answer>
          <answer correct="false">Philadelphia</answer>
      </quizquestion>
  
      <quizquestion>
          <header_image_src>ic_help_black_24dp</header_image_src>
          <question>What is the family name of the famous dutch painter Vincent Willem van .... ?</question>
          <input_type>EditText</input_type>              
          <answer correct="true">Gogh</answer>
      </quizquestion>
  </quizquestions>
  

• 保存解析数据的 Java 类：

  public class QuizQuestion {
      private int headerImageResId;
      private String question;
      private String inputType;
      private ArrayList<String> answers;
      private ArrayList<Boolean> answerIsCorrect;
      private ArrayList<Integer> correctAnswerIndexes;
  
      /**
       * constructor for QuizQuestion object
       */
      QuizQuestion() {
          headerImageResId = 0;
          question = null;
          inputType = null;
          answers = new ArrayList<>();
          answerIsCorrect = new ArrayList<>();
          correctAnswerIndexes = new ArrayList<>();
      }
  
  
      public void setHeaderImageResId(int headerImageResId) {
          this.headerImageResId = headerImageResId;
      }
  
      public int getHeaderImageResId() {
          return headerImageResId;
      }
  
  
      void setQuestion(String question) {
          this.question = question;
      }
  
      public String getQuestion() {
          return question;
      }
  
  
      void setInputType(String inputType) {
          this.inputType = inputType;
      }
  
      public String getInputType() {
          return inputType;
      }
  
      void addAnswer(String answer, boolean isCorrect)
      {
          if (isCorrect)
              correctAnswerIndexes.add(answers.size());
          answers.add(answer);
          answerIsCorrect.add(isCorrect);
      }
  
  
      public ArrayList<String> getAnswers() {
          return answers;
      }
  
      public String getAnswer(int index)
      {
          // check index to avoid out of bounds exception
          if (index < answers.size()) {
              return answers.get(index);
          }
          else
          {
              return null;
          }
      }
  
      public int size()
      {
          return answers.size();
      }
  
  }
  

• 解析器本身：

  /**
   * Created by bivanbi on 2017.02.23..
   *
   * class to parse xml resource containing quiz data into ArrayList of QuizQuestion objects
   *
   */
  
  public class QuizXmlParser {
  
      public static String lastErrorMessage = "";
  
      /**
       * static method to parse XML data into ArrayList of QuizQuestion objects
       * @param activity is the calling activity
       * @param xmlResourceId is the resource id of XML resource to be parsed
       * @return null if parse error is occurred or ArrayList of objects if successful
       * @throws XmlPullParserException
       * @throws IOException
       */
      public static ArrayList<QuizQuestion> parse(Activity activity, int xmlResourceId)
              throws XmlPullParserException, IOException
      {
          String logTag = QuizXmlParser.class.getSimpleName();
          Resources res = activity.getResources();
          XmlResourceParser quizDataXmlParser = res.getXml(R.xml.quiz_data);
  
          ArrayList<String> xmlTagStack = new ArrayList<>();
          ArrayList<QuizQuestion> quizQuestions = new ArrayList<>();
  
          QuizQuestion currentQuestion = null;
  
          boolean isCurrentAnswerCorrect = false;
  
          quizDataXmlParser.next();
          int eventType = quizDataXmlParser.getEventType();
          while (eventType != XmlPullParser.END_DOCUMENT)
          {
              //  begin document
              if(eventType == XmlPullParser.START_DOCUMENT)
              {
                  Log.d(logTag,"Begin Document");
              }
              //  begin tag
              else if(eventType == XmlPullParser.START_TAG)
              {
                  String tagName = quizDataXmlParser.getName();
                  xmlTagStack.add(tagName);
                  Log.d(logTag,"Begin Tag "+tagName+", depth: "+xmlTagStack.size());
                  Log.d(logTag,"Tag "+tagName+" has "+quizDataXmlParser.getAttributeCount()+" attribute(s)");
  
                  // this is a beginning of a quiz question tag so create a new QuizQuestion object
                  if (tagName.equals("quizquestion")){
                      currentQuestion = new QuizQuestion();
                  }
                  else if(tagName.equals("answer"))
                  {
                      isCurrentAnswerCorrect = quizDataXmlParser.getAttributeBooleanValue(null,"correct",false);
                      if (isCurrentAnswerCorrect == true) {
                          Log.d(logTag, "Tag " + tagName + " has attribute correct = true");
                      }
                      else
                      {
                          Log.d(logTag, "Tag " + tagName + " has attribute correct = false");
                      }
                  }
              }
              //  end tag
              else if(eventType == XmlPullParser.END_TAG)
              {
                  String tagName = quizDataXmlParser.getName();
                  if (xmlTagStack.size() < 1)
                  {
                      lastErrorMessage = "Error 101: encountered END_TAG "+quizDataXmlParser.getName()+" while TagStack is empty";
                      Log.e(logTag, lastErrorMessage);
                      return null;
                  }
                  xmlTagStack.remove(xmlTagStack.size()-1);
                  Log.d(logTag,"End Tag "+quizDataXmlParser.getName()+", depth: "+xmlTagStack.size());
  
                  //  reached the end of a quizquestion definition, add it to the array
                  if (tagName.equals("quizquestion")){
                      if (currentQuestion != null)
                          quizQuestions.add(currentQuestion);
                      currentQuestion = null;
                  }
              }
              //  text between tag begin and end
              else if(eventType == XmlPullParser.TEXT)
              {
                  String currentTag = xmlTagStack.get(xmlTagStack.size()-1);
                  String text = quizDataXmlParser.getText();
                  Log.d(logTag,"Text: "+text+", current tag: "+currentTag+", depth: "+xmlTagStack.size());
  
                  if (currentQuestion == null) {
                      Log.e(logTag,"currentQuestion is not initialized! text: "+text+", current tag: "+currentTag+", depth: "+xmlTagStack.size());
                      continue;
                  }
  
                  if (currentTag.equals("header_image_src"))
                  {
                      int drawableResourceId = activity.getResources().getIdentifier(text, "drawable", activity.getPackageName());
                      currentQuestion.setHeaderImageResId(drawableResourceId);
                  }
                  else if (currentTag.equals("question"))
                  {
                      currentQuestion.setQuestion(text);
                  }
                  else if (currentTag.equals("answer"))
                  {
                      currentQuestion.addAnswer(text, isCurrentAnswerCorrect);
                  }
                  else if (currentTag.equals("input_type"))
                  {
                      currentQuestion.setInputType(text);
                  }
                  else
                  {
                      Log.e(logTag,"Unexpected tag "+currentTag+" with text: "+text+", depth: "+xmlTagStack.size());
                  }
              }
              eventType = quizDataXmlParser.next();
          }
          Log.d(logTag,"End Document");
          return quizQuestions;
      }
  
  }
  

• 最后，调用解析器：

  //  read quiz data from xml resource quiz_data
  try {
      quizQuestions = QuizXmlParser.parse(this,R.xml.quiz_data);
      Log.d("Main","QuizQuestions: "+quizQuestions);
  
  } catch (XmlPullParserException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      quizQuestions = null;
  } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      quizQuestions = null;
  }
  
  if (quizQuestions == null)
  {
      Toast.makeText(this,"1001 Failed to parse Quiz XML, sorry", Toast.LENGTH_LONG).show();
      finish();
  }