java 如何在 Android Studio 中将 CSV 文件解析为数组

How to parse CSV file into an array in Android Studio

提问by Varun Vu

i'm wondering how to parse a CSV file and just store the contents into an array. My csv file looks something like this:

我想知道如何解析 CSV 文件并将内容存储到数组中。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

I only want the names, so the second field. I want to store all of these items in the csv into an array or arraylist of string.

我只想要名字，所以第二个字段。我想将 csv 中的所有这些项目存储到字符串数组或数组列表中。

Any ideas how to do this?

任何想法如何做到这一点？

Any help would be greatly appreciated!

任何帮助将不胜感激！

回答by Shubham Sharma

Where to put the CSV file in AndroidCreate a folder named “raw” inside the “res” folder and put the CSV file in it.

CSV文件在Android中的放置位置在“res”文件夹中创建一个名为“raw”的文件夹并将CSV文件放入其中。

How to read CSV file, Nothing special since its Android. All we are going to use our standard Java code. Its better to use our own code instead of going to an API. Following class is an utility to read CSV file and it can be used from within the Android application. In which array we will store items of csv fileIn these example it is scorelist arraylist .

如何读取 CSV 文件，自 Android 以来没什么特别的。我们将使用我们的标准 Java 代码。最好使用我们自己的代码而不是去 API。下面的类是一个读取 CSV 文件的实用程序，它可以在 Android 应用程序中使用。 我们将在哪个数组中存储 csv 文件的项目在这些示例中它是 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;
    }
}

So how to load the CSV file from “raw” folder and use the above utility to read it?

那么如何从“raw”文件夹中加载 CSV 文件并使用上述实用程序来读取它呢？

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

MainActivity.java

主活动.java

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

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;
    }
}

activity_mail.xml

活动邮件.xml

<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

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>

For the whole source code you can refers to these link javapapers.com/wp-content/uploads/2014/07/CSVFileRead.zip

对于整个源代码，您可以参考这些链接javapapers.com/wp-content/uploads/2014/07/CSVFileRead.zip

I think it will help

我认为它会有所帮助

回答by kamoroso94

Disclaimer:I've never worked with Android, but I do know Java, so hopefully it's all the same.

免责声明：我从未使用过 Android，但我确实了解 Java，所以希望一切都一样。

That being said, you can try something like this.

话虽如此，你可以尝试这样的事情。

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

回答by Joshy Francis

A better CSV parser handles quoted fields

更好的 CSV 解析器处理引用的字段

    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;
        }
    }

Usage

用法

    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();

Sample data used
ID,Name
1,Test Item 1
"2","Test Item 2"
"3","Test , Item 3"
4,Test Item 4

使用的样本数据
ID,Name
1,Test Item 1
"2","Test Item 2"
"3","Test , Item 3"
4,Test Item 4

回答by Emi Raz

I extended Sharma's answer to making the core class more flexible in a variety of conditions of the CSV file. I prefer the builder design pattern for configuring how to read the CSV file.

我扩展了 Sharma 的答案，使核心类在 CSV 文件的各种条件下更加灵活。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;
    }
}

回答by Rohan

Android by default does not create the raw folder.Create a raw folder under res/raw in your project. copy your CSV File in that. keep the name of the CSV file lower case and convert into text format when asked. my CSV file name is welldata.scv WellData - it is the model class with getter and setter. wellDataList is the ArrayList to store the data.

Android默认不会创建raw文件夹。在你的项目中res/raw下创建一个raw文件夹。复制您的 CSV 文件。保持 CSV 文件的名称小写，并在询问时转换为文本格式。我的 CSV 文件名是 welldata.scv WellData - 它是带有 getter 和 setter 的模型类。wellDataList 是用于存储数据的 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();
}

} }

} }