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Java如何讀取csv文件并將數(shù)據(jù)放入對象中

更新時(shí)間：2025年04月22日 09:00:30 作者：早睡早起愛學(xué)習(xí)i

這篇文章主要介紹了Java如何讀取csv文件并將數(shù)據(jù)放入對象中的實(shí)現(xiàn)方式,具有很好的參考價(jià)值,希望對大家有所幫助,如有錯誤或未考慮完全的地方,望不吝賜教

讀取csv文件并封裝數(shù)據(jù)為對象

例如

圖中的一個 .csv 文件，需要讀取數(shù)據(jù)封裝對象進(jìn)行數(shù)據(jù)持久化。

public static void readCSV(String readpath, ArrayList list)
{
    File inFile = new File(readpath);
    try
    {
        BufferedReader reader = new BufferedReader(new FileReader(inFile));
        boolean sign = false;       //用來跳過第一行的名稱
        while(reader.ready())
        {
            String line = reader.readLine();
            StringTokenizer st = new StringTokenizer(line, ",");
            int date, time, num_transaction, response_time;
            double sucRate;

            if (st.hasMoreTokens() && sign)
            {
                date = Integer.valueOf(st.nextToken().trim());
                time = Integer.valueOf(st.nextToken().trim());
                num_transaction = Integer.valueOf(st.nextToken().trim());
                sucRate = Double.valueOf(st.nextToken().trim());
                response_time = Integer.valueOf(st.nextToken().trim());

                Sample sample = new Sample(date, time, num_transaction, sucRate, response_time);
                list.add(sample);
            }
            else
            {
                sign = true;
            }
        }
        reader.close();

    }
    catch (FileNotFoundException e)
    {

        e.printStackTrace();
    }
    catch (IOException e)
    {

        e.printStackTrace();
    }
}

當(dāng)有多個對象時(shí)

可以傳入一個 Class對象來獲取到需要封裝對象的類名，進(jìn)一步實(shí)現(xiàn)方法一般化：

public class ReadCSV {
    public static void readCSV(InputStream inputStream, ArrayList<Object> list, Class cls){
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new InputStreamReader(inputStream));
            boolean flag = false;
            ArrayList<String> headerList = new ArrayList();
            while(reader.ready()){
                String line = reader.readLine();
                StringTokenizer st = new StringTokenizer(line,",");
                        //處理當(dāng)前行數(shù)據(jù)
                if(st.hasMoreTokens() && flag){
                    String typeName = cls.getSimpleName();
                    //如果文件中存儲的是 EnergyProvince類信息
                    if(typeName.equals("EnergyProvice")){
                        String provinceName = st.nextToken();
//                        Float year2019 = Float.valueOf(st.nextToken());
//                        Float year2018 = Float.valueOf(st.nextToken());
                        Float year2017 = Float.valueOf(st.nextToken());
                        Float year2016 = Float.valueOf(st.nextToken());
                        Float year2015 = Float.valueOf(st.nextToken());
                        Float year2014 = Float.valueOf(st.nextToken());
                        Float year2013 = Float.valueOf(st.nextToken());
                        Float year2012 = Float.valueOf(st.nextToken());
                        Float year2011 = Float.valueOf(st.nextToken());
                        Map<String,Float> dataMap = new HashMap();
//                        dataMap.put(headerList.get(1),year2019);
//                        dataMap.put(headerList.get(2),year2018);
                        dataMap.put(headerList.get(1),year2017);
                        dataMap.put(headerList.get(2),year2016);
                        dataMap.put(headerList.get(3),year2015);
                        dataMap.put(headerList.get(4),year2014);
                        dataMap.put(headerList.get(5),year2013);
                        dataMap.put(headerList.get(6),year2012);
                        dataMap.put(headerList.get(7),year2011);
                        list.add(new EnergyProvice(provinceName,dataMap));
                    }
                }
                else{   //添加表頭到 List 集合
                    while(st.hasMoreTokens()){
                        headerList.add(st.nextToken());
                    }
                    flag=true;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if(reader!=null)
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
        }
    }