如何在Android Studio中将CSV文件解析为数组

12

我想知道如何解析CSV文件并将其内容存储到数组中。我的CSV文件看起来像这样:

1,bulbasaur,1,7,69,64,1,1
2,ivysaur,2,10,130,142,2,1
我只需要名字,也就是第二个字段。我想将所有这些项目存储到字符串数组或列表中。有任何想法吗?非常感谢您的帮助!
5个回答

21

在Android中应将CSV文件放在哪里 在“res”文件夹中创建一个名为“raw”的文件夹,然后将CSV文件��入其中。

如何读取CSV文件 由于这是Android平台,所以没有什么特别的。我们将使用标准的Java代码。最好使用自己的代码而不是去调用API。以下类是一种实用程序,用于读取CSV文件,它可以从Android应用程序内部使用。 我们将把CSV文件的项目存储在哪个数组中? 在这个例子中,它是scorelist arraylist。

public class CSVFile {
    InputStream inputStream;

    public CSVFile(InputStream inputStream){
        this.inputStream = inputStream;
    }

    public List read(){
        List resultList = new ArrayList();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        try {
            String csvLine;
            while ((csvLine = reader.readLine()) != null) {
                String[] row = csvLine.split(",");
                resultList.add(row);
            }
        }
        catch (IOException ex) {
            throw new RuntimeException("Error in reading CSV file: "+ex);
        }
        finally {
            try {
                inputStream.close();
            }
            catch (IOException e) {
                throw new RuntimeException("Error while closing input stream: "+e);
            }
        }
        return resultList;
    }
}

那么如何从“raw”文件夹中加载CSV文件并使用上述工具来读取它呢?

InputStream inputStream = getResources().openRawResource(R.raw.stats);
CSVFile csvFile = new CSVFile(inputStream);
List scoreList = csvFile.read();

MainActivity.java

:MainActivity.java 文件。
public class MainActivity extends Activity {
    private ListView listView;
    private ItemArrayAdapter itemArrayAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView) findViewById(R.id.listView);
        itemArrayAdapter = new ItemArrayAdapter(getApplicationContext(), R.layout.item_layout);

        Parcelable state = listView.onSaveInstanceState();
        listView.setAdapter(itemArrayAdapter);
        listView.onRestoreInstanceState(state);

        InputStream inputStream = getResources().openRawResource(R.raw.stats);
        CSVFile csvFile = new CSVFile(inputStream);
        List scoreList = csvFile.read();

        for(String[] scoreData:scoreList ) {
            itemArrayAdapter.add(scoreData);
        }
    }
}

ItemArrayAdapter.java

public class ItemArrayAdapter extends ArrayAdapter {
    private List scoreList = new ArrayList();

    static class ItemViewHolder {
        TextView name;
        TextView score;
    }

    public ItemArrayAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    @Override
    public void add(String[] object) {
        scoreList.add(object);
        super.add(object);
    }

    @Override
    public int getCount() {
        return this.scoreList.size();
    }

    @Override
    public String[] getItem(int index) {
        return this.scoreList.get(index);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        ItemViewHolder viewHolder;
        if (row == null) {
            LayoutInflater inflater = (LayoutInflater) this.getContext().
                    getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = inflater.inflate(R.layout.item_layout, parent, false);
            viewHolder = new ItemViewHolder();
            viewHolder.name = (TextView) row.findViewById(R.id.name);
            viewHolder.score = (TextView) row.findViewById(R.id.score);
            row.setTag(viewHolder);
        } else {
            viewHolder = (ItemViewHolder)row.getTag();
        }
        String[] stat = getItem(position);
        viewHolder.name.setText(stat[0]);
        viewHolder.score.setText(stat[1]);
        return row;
    }
}

活动邮件模板

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.javapapers.android.csvfileread.app.MainActivity">
    <ListView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/listView"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp" />
</RelativeLayout>

item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/name"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="20dp" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/score"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_marginRight="20dp" />
</RelativeLayout>

您可以参考以下链接获取完整的源代码:javapapers.com/wp-content/uploads/2014/07/CSVFileRead.zip

我认为这会有所帮助。


如果在嵌套引号中嵌套了逗号,那么这样做能避免字符串被分割吗? - Dustin K
公共类CSVFile应该放在MainActivity.java中的哪里? - GeneCode
我的 CSV 文件相当大,在“scoreData”中只有前10-12行的项目。CSV 文件没有换行符或其他东西,只是用逗号分隔项目。 - Lidor Eliyahu Shelef

5
更好的CSV解析器处理带引号的字段。
    import android.content.Context;
    import android.widget.Toast;
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.List;

    public class CSVReader {
        private class StringDArray {
            private String[] data=new String[0];
            private int used=0;
            public void add(String str) {
                if (used >= data.length){
                    int new_size= used+1;
                    String[] new_data=new String[new_size];
                    java.lang.System.arraycopy( data,0,new_data,0,used);
                    data=new_data;
                }
                data[used++] = str;
            }
            public int length(){
                return  used;
            }
            public String[] get_araay(){
                return data;
            }
        }
        private  Context context;
        public CSVReader(Context context){
            this.context=context;
        }
        public List read(File file){
            List resultList = new ArrayList();
            try{
                InputStream inputStream= new FileInputStream(file);
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
                String csvLine;
                final char Separator = ',';
                final char Delimiter = '"';
                final char LF = '\n';
                final char CR = '\r';
                boolean quote_open = false;
                while ((csvLine = reader.readLine()) != null) {
                    //String[] row = csvLine.split(",");// simple way
                    StringDArray a=new StringDArray();
                    String token="";
                        csvLine+=Separator;
                    for(char c:csvLine.toCharArray()){
                        switch (c){
                            case LF: case CR:// not required as we are already read line
                                quote_open=false;
                                a.add(token);
                                token="";
                            break;
                            case Delimiter:
                                quote_open=!quote_open;
                            break;
                            case Separator:
                                if(quote_open==false){
                                    a.add(token);
                                    token="";
                                }else{
                                    token+=c;
                                }
                            break;
                            default:
                                token+=c;
                            break;
                        }
                    }
                    if(a.length()>0 ) {
                        if(resultList.size()>0){
                            String[] header_row =(String[]) resultList.get(0);
                            if(a.length()>=header_row.length) {
                                String[] row = a.get_araay();
                                resultList.add(row);
                            }
                        }else{
                            String[] row = a.get_araay();
                            resultList.add(row);//header row
                        }
                    }
                }
                inputStream.close();
            }catch (Exception e){
                Toast.makeText(context,"Error : " + e.getMessage(), Toast.LENGTH_LONG).show();
            }
            return resultList;
        }
    }

使用方法

    File file=new File(path);
    CSVReader csvReader=new CSVReader(activity.this);
    List csv=csvReader.read(file);
    if(csv.size()>0){
        String[] header_row =(String[]) csv.get(0);
        if(header_row.length>1){
            String col1=header_row[0];
            String col2=header_row[1];
        }
    }

    Toast.makeText(activity.this,csv.size() + " rows", Toast.LENGTH_LONG).show();

使用的示例数据
ID,名称
1,测试项目1
"2","测试项目2"
"3","测试,项目3"
4,测试项目4


1

免责声明:我从未与Android工作过,但我知道Java,希望它们是相同的。

话虽如此,你可以尝试这样做。

Scanner scanner = new Scanner(new File("file.csv"));
ArrayList<String> pokemon = new ArrayList<>();
while(scanner.hasNextLine()) {
    pokemon.add(scanner.nextLine().split(",")[1]);
}
scanner.close();

0

Android默认情况下不创建raw文件夹。在您的项目中,在res/raw下创建一个raw文件夹。将CSV文件复制到该文件夹中。请将CSV文件名以小写形式保存并在要求时转换为文本格式。我的CSV文件名是welldata.scv,WellData是具有getter和setter的模型类,wellDataList是存储数据的ArrayList。

private void readData() {
InputStream is = getResources().openRawResource(R.raw.welldata);
BufferedReader reader = new BufferedReader(
        new InputStreamReader(is, Charset.forName("UTF-8")));
String line = "";
try {
    while ((line = reader.readLine()) != null) {
       //set splitter
        String[] tokens = line.split(",");

        //read the data
        WellData wellData = new WellData();
        wellData.setOwner(tokens[0]);
        wellData.setApi(tokens[1]);
        wellData.setLongitude(tokens[2]);
        wellData.setLatitude(tokens[3]);
        wellData.setProperty(tokens[4]);
        wellData.setWellName(tokens[5]);
        wellDataList.add(wellData);

        Log.d("MainActivity" ,"Just Created " +wellData);

    }
} catch (IOException e1) {
    Log.e("MainActivity", "Error" + line, e1);
    e1.printStackTrace();
}

} }


0
我在Sharma的回答基础上进行了扩展,使核心类能够在各种CSV文件条件下更加灵活。我更喜欢使用构建器设计模式来配置如何读取CSV文件。
public class CSVFile {
    private static final Charset UTF8 = Charset.forName("UTF-8");
    private final static String DEFAULT_DELIMITER = ",";

    private InputStream inputStream;
    private Charset charset;
    private String delimiter;
    private boolean ignoreHead;

    public CSVFile(InputStream inputStream) {
        this.inputStream = inputStream;
        this.charset = UTF8;
        this.delimiter = DEFAULT_DELIMITER;
        this.ignoreHead = false;
    }

    public CSVFile setCharset(Charset charset) {
        this.charset = charset;
        return this;
    }

    public CSVFile setDelimiter(String delimiter) {
        this.delimiter = delimiter;
        return this;
    }

    public CSVFile ignoreHead() {
        ignoreHead = true;
        return this;
    }

    public List<String[]> read() {
        boolean firstRow = true;
        List<String[]> resultList = new ArrayList<>();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, charset));
        try {
            String csvLine;
            while ((csvLine = reader.readLine()) != null) {
                if (firstRow) {
                    firstRow = false;

                    if (ignoreHead) {
                        continue;
                    }
                }

                String[] row = csvLine.split(delimiter);
                resultList.add(row);
            }
        } catch (IOException ex) {
            throw new RuntimeException("Error in reading CSV file: " + ex);
        } finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                throw new RuntimeException("Error while closing input stream: " + e);
            }
        }
        return resultList;
    }
}

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