[SuperCSV]讀取csv檔案

Super CSV是個操作csv檔案的Open Source

由於我需要的是讀取csv檔案資料
所以Code example也只先看這一部份了

實作上可以分做兩種情況
已知檔案格式和未知檔案格式

在已知的情況下
就它的範例
File Header的部份為以下
username, password, date, zip, town
Klaus, qwexyKiks, 17/1/2007, 1111, New York
Oufu, bobilop, 10/10/2007, 4555, New York

便可以做出對應的bean

public class UserBean {
   String username, password, street, town;
   int zip;

   public String getPassword() { return password; }
   public String getStreet() { return street; }
   public String getTown() { return town; }
   public String getUsername() { return username; }
   public int getZip() { return zip; }
   public void setPassword(String password) { this.password = password; }
   public void setStreet(String street) { this.street = street; }
   public void setTown(String town) { this.town = town; }
   public void setUsername(String username) { this.username = username; }
   public void setZip(int zip) { this.zip = zip; }
}

再來
可以透過processor做Header各欄位的格式檢查

final CellProcessor[] processors = new CellProcessor[] {
   new Unique(new StrMinMax(5, 20)),
   new StrMinMax(8, 35),
   new ParseDate("dd/MM/yyyy"),
   new Optional(new ParseInt()),
   null
};

最後就是讀取的部份

class ReadingObjects {
   public static void main(String[] args) throws Exception{
       ICsvBeanReader inFile = new CsvBeanReader(new FileReader("foo.csv"), CsvPreference.EXCEL_PREFERENCE);
       try {
           final String[] header = inFile.getCSVHeader(true);
           UserBean user;
           while( (user = inFile.read(UserBean.class, header, processors)) != null) {
               System.out.println(user.getZip());
           }
       } finally {
           inFile.close();
       }
   }
} 

雖然沒實際去測試
如果header的字眼有空白,特殊符號之類
這樣bean的方法是不是就不能用了?

第二類是未知格式
這部份在官網只寫了

You accomplish this using the CsvListReader.read() method

果然也是很簡單
我把方法寫在一起
可以做個對照

public static void main(String[] args) throws Exception {
   ICsvBeanReader inFile = new CsvBeanReader(new FileReader("foo.csv"), CsvPreference.EXCEL_PREFERENCE);
   CsvListReader r = new CsvListReader(new FileReader("foo.csv"), CsvPreference.EXCEL_PREFERENCE);
   try {
       final String[] header = inFile.getCSVHeader(true);
       for(int j=0;j<header.length;j++){
           System.out.println(header[j]);
       }
       UserBean user;
       while( (user = inFile.read(UserBean.class, header, userProcessors)) != null) {
           System.out.println(user.getZip());
       }
       List l;
       while( (l = r.read()) !=null ){
           System.out.println(l.get(0));
       }
   } finally {
       inFile.close();
   } 
}