Java如何读取csv文件并将数据放入对象中

目录

• 读取csv文件并封装数据为对象
• 例如
• 当有多个对象时
• 总结

读取csv文件并封装数据为对象

例如

图中的一个 .csv 文件，需要读取数据封装对象进行数据持久化。

public static void readCSV(String readpath, ArrayList list)
{
    File inFile = new File(readpath);
    try
    {
        BufferedReader reader = new BufferedReader(new FileReader(inFile));
        boolean sign = false;       //用来跳过第一行的名称
        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());
 编程客栈               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();
    }
}

当有多个对象时

可以传入一个 Class对象来获取到需要封装对象的类名，进一步实现方法一般化：

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 ArrandroidayList();
            while(reader.ready()){
                String line = reader.readLine();
                StringTokenizer st = new StringTokenizer(line,",");
                        //处理当前行数据
                if(st.hasMoreTokens() && flag){
                    String typeName = cls.getSimpleN编程客栈ame();
                    //如果文件中存储的是 EnergyProvince类信息
                    if(typeName.equals("EnergyProvice")){
                        String provinceName = st.nextToken();
//                        Float year2019 = Float.valueOf(st.nextToken());
//                     javascript   Float year2018 = Float.valueOf(st.nextToken());
                        Float year2017 = Float.valueOf(st.nextToken());
     编程客栈                   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{   //添加表头到 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();
                }
        }
    }

总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程客栈(www.devze.com)。