android - 在资源文件夹android中读取CSV文件

Question

我正在 netbeans 中开发一个 android 应用程序。我正在尝试使用 opencsv 读取 CSV 文件。当我将文件放入资源文件夹并尝试从那里读取它时，在构建无效资源目录时出现错误。我应该在哪里存储 csv 文件，以便每次应用程序启动时都可以读取它？

Answer 1

您应该将 csv 文件放在资产文件夹中..

InputStreamReader is = new InputStreamReader(getAssets()
                        .open("filename.csv"));

BufferedReader reader = new BufferedReader(is);
reader.readLine();
String line;
while ((line = reader.readLine()) != null) {
                        
}

Answer 2

一些建议；

• 创建一个对象，用于将一行数据保存到 csv 中。( Ex: YourSimpleObject. 它使您可以轻松管理数据。)
• 逐行读取文件并分配给对象。将对象添加到列表中。（例如ArrayList<YourSimpleObject >：）

代码：

private void readAndInsert() throws UnsupportedEncodingException {


ArrayList<YourSimpleObject > objList= new ArrayList<YourSimpleObject >();
AssetManager assetManager = getAssets();
InputStream is = null;

            try {
                is = assetManager.open("questions/question_bank.csv");
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            BufferedReader reader = null;
            reader = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));

            String line = "";
            StringTokenizer st = null;
            try {

                while ((line = reader.readLine()) != null) {
                    st = new StringTokenizer(line, ",");
                    YourSimpleObject obj= new YourSimpleObject ();
                                    //your attributes
                    obj.setX(st.nextToken());
                    obj.setY(st.nextToken());
                    obj.setZ(st.nextToken());
                    obj.setW(st.nextToken());

                    objList.add(sQuestion);

                }
            } catch (IOException e) {

                e.printStackTrace();
            }



}

Answer 3

作为替代方案，请查看uniVocityParsers。它提供了大量解析分隔文件的方法。下面的示例将一个 Csv 文件（见下图）从 res/raw 文件夹加载到 InputStream 对象中，并以列的方式读取它（key=Column & value=ColumnValues 的映射）。

calendario_bolsa.csv

//Gets your csv file from res/raw dir and load into a InputStream.
InputStream csvInputStream = getResources().openRawResource(R.raw.calendario_bolsa);

//Instantiate a new ColumnProcessor
ColumnProcessor columnProcessor = new ColumnProcessor();

//Define a class that hold the file configuration
CsvParserSettings parserSettings = new CsvParserSettings();
parserSettings.getFormat().setLineSeparator("\n");
parserSettings.setHeaderExtractionEnabled(true);
parserSettings.setProcessor(columnProcessor);

//Creates a new CsvParser, passing the settings into its construtor:
CsvParser csvParser = new CsvParser(parserSettings);

//Calls parse method, instantiating an InputStreamReader, passing to its constructor the InputStream object
csvParser.parse(new InputStreamReader(csvInputStream));

//Gets the csv data as a Map of Column / column values.
Map<String, List<String>> columnarCsv = columnProcessor.getColumnValuesAsMapOfNames();

要将 univocityParsers 添加到您的 Android 项目中：

compile group: 'com.univocity', name: 'univocity-parsers', version: '2.3.0'

Answer 4

使用 opencsv：

InputStream is = context.getAssets().open(path);
InputStreamReader reader = new InputStreamReader(is, Charset.forName("UTF-8"));
List<String[]> csv = new CSVReader(reader).readAll();

Answer 5

您可以使用此代码

   try {
                InputStream csvStream = assetManager.open(CSV_PATH);
                InputStreamReader csvStreamReader = new        InputStreamReader(csvStream);
                CSVReader csvReader = new CSVReader(csvStreamReader);
                String[] line;

                // throw away the header
                csvReader.readNext();

                while ((line = csvReader.readNext()) != null) {
                  questionList.add(line);
                }
              } catch (IOException e) {
                e.printStackTrace();
              }

您可以从http://sourceforge.net/projects/opencsv/files/latest/download下载 csvreader 文件

并导入您的项目