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私はJavaが初めてです。7 列の CSV ファイルを読み取る方法を教えてもらえますか?

これが私のコードです：

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class main {

    public static  Map<String,String> map1 = null;
    public static  Map<String,String> map2 = null;

    public static void main(String[] args) {
        try {
            readFileandPopulate();
            for (Map.Entry<String, String> entry : map1.entrySet()) {
                System.out.println("Key : " + entry.getKey() + " Value : "
                    + entry.getValue()+" address :"+map2.get(entry.getKey()));
                //insert into DB
            }
        } catch (Exception e) {//Catch exception if any
            e.printStackTrace();
            System.err.println("Error: " + e.getMessage());
        }
    }

    public static void readFileandPopulate() throws Exception {
        FileInputStream fstream = new FileInputStream("/Users/Desktop/Pattern Recognition/DataSetR/1a19.csv");
        // Use DataInputStream to read binary NOT text.
        BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
        String strLine;
        map1 = new HashMap<String,String>();
        while ((strLine = br.readLine()) != null) {
            System.out.println(strLine);
            String temp[] = strLine.split(",");
            map1.put(temp[0], temp[1]);
        }
        in.close();
        System.out.println("done 1");

    }
}

いくつかの列を読み取って残りのデータを削除する方法はありますか、またはすべての値を配列に格納し、配列のインデックスを使用して値を使用して1つの方程式を計算できますか?

4

2 に答える 2

0 
import java.io.FileReader;
import java.io.IOException;
import java.util.List;

import au.com.bytecode.opencsv.CSVReader;

public class ReadCSV 
{
    public static void main(String[] args) throws IOException 
    {
        String[] row = null;
        String csvFilename = "C:/Users/Hussain/Desktop/data.csv";
        CSVReader csvReader = new CSVReader(new FileReader(csvFilename));
        List content = csvReader.readAll();
        for (Object object : content) 
        {
            row = (String[]) object;
            System.out.println("value in row 7 ===>>>"+row[6]);
        }
        csvReader.close();
        }
}

ここからjarを追加できます

于 2013-02-16T19:46:00.607 に答える
0

I would recommend using a CSV parser, such as http://opencsv.sourceforge.net/. Then you could do the following:

CSVReader reader = new CSVReader(new FileReader(filePath), ',');

List<String[]> rows= reader.readAll();

for (String[] row : rows)
{
    for (int i = 0; i < numColumnsToParse; i++)
    {
        //do something with row[i]
    }
}
于 2013-02-16T19:08:51.563 に答える