Java如何读取csv文件并将数据放入对象中

凌溶溶

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。

1. public static void readCSV(String readpath, ArrayList list)
2. {
3. File inFile = new File(readpath);
4. try
5. {
6. BufferedReader reader = new BufferedReader(new FileReader(inFile));
7. boolean sign = false; //用来跳过第一行的名称
8. while(reader.ready())
9. {
10. String line = reader.readLine();
11. StringTokenizer st = new StringTokenizer(line, ",");
12. int date, time, num_transaction, response_time;
13. double sucRate;
15. if (st.hasMoreTokens() && sign)
16. {
17. date = Integer.valueOf(st.nextToken().trim());
18. time = Integer.valueOf(st.nextToken().trim());
19. num_transaction = Integer.valueOf(st.nextToken().trim());
20. sucRate = Double.valueOf(st.nextToken().trim());
21. response_time = Integer.valueOf(st.nextToken().trim());
23. Sample sample = new Sample(date, time, num_transaction, sucRate, response_time);
24. list.add(sample);
25. }
26. else
27. {
28. sign = true;
29. }
30. }
31. reader.close();
33. }
34. catch (FileNotFoundException e)
35. {
37. e.printStackTrace();
38. }
39. catch (IOException e)
40. {
42. e.printStackTrace();
43. }
44. }

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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：

1. public class ReadCSV {
2. public static void readCSV(InputStream inputStream, ArrayList<Object> list, Class cls){
3. BufferedReader reader = null;
4. try {
5. reader = new BufferedReader(new InputStreamReader(inputStream));
6. boolean flag = false;
7. ArrayList<String> headerList = new ArrayList();
8. while(reader.ready()){
9. String line = reader.readLine();
10. StringTokenizer st = new StringTokenizer(line,",");
11. //处理当前行数据
12. if(st.hasMoreTokens() && flag){
13. String typeName = cls.getSimpleName();
14. //如果文件中存储的是 EnergyProvince类信息
15. if(typeName.equals("EnergyProvice")){
16. String provinceName = st.nextToken();
17. // Float year2019 = Float.valueOf(st.nextToken());
18. // Float year2018 = Float.valueOf(st.nextToken());
19. Float year2017 = Float.valueOf(st.nextToken());
20. Float year2016 = Float.valueOf(st.nextToken());
21. Float year2015 = Float.valueOf(st.nextToken());
22. Float year2014 = Float.valueOf(st.nextToken());
23. Float year2013 = Float.valueOf(st.nextToken());
24. Float year2012 = Float.valueOf(st.nextToken());
25. Float year2011 = Float.valueOf(st.nextToken());
26. Map<String,Float> dataMap = new HashMap();
27. // dataMap.put(headerList.get(1),year2019);
28. // dataMap.put(headerList.get(2),year2018);
29. dataMap.put(headerList.get(1),year2017);
30. dataMap.put(headerList.get(2),year2016);
31. dataMap.put(headerList.get(3),year2015);
32. dataMap.put(headerList.get(4),year2014);
33. dataMap.put(headerList.get(5),year2013);
34. dataMap.put(headerList.get(6),year2012);
35. dataMap.put(headerList.get(7),year2011);
36. list.add(new EnergyProvice(provinceName,dataMap));
37. }
38. }
39. else{ //添加表头到 List 集合
40. while(st.hasMoreTokens()){
41. headerList.add(st.nextToken());
42. }
43. flag=true;
44. }
45. }
46. } catch (Exception e) {
47. e.printStackTrace();
48. } finally {
49. if(reader!=null)
50. try {
51. reader.close();
52. } catch (IOException e) {
53. e.printStackTrace();
54. }
55. }
56. }

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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晓枫资讯。

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