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 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | 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()); 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：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | public class ReadCSV { public static void readCSV(InputStream inputStream, ArrayList<object data-origwidth="" data-origheight="" style="width: 1264px;"> list, Class cls){ BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(inputStream)); boolean flag = false; ArrayList headerList = new ArrayList(); 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.getSimpleName(); //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());// 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 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(); } } }</object> |
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IT俱乐部。
