java apache poi(第 1 部分) [英] java apache poi (part 1)

问题描述

• excel文件(staff.xls)
  身份证    姓名
  1       阿里
  2       阿布
  3       艾哈迈德
  

• java 代码

  FileInputStream inputFile = new FileInputStream("staff.xls");XSSFWorkbook 工作簿 = new XSSFWorkbook(inputFile);XSSFSheet 电子表格 = workbook.getSheetAt(0);XSSFRow 行；细胞细胞；迭代器<行>rowIterator = 电子表格.迭代器()；while(rowIterator.hasNext()){row = (XSSFRow)rowIterator.next();迭代器<Cell>cellIterator = row.cellIterator();while(cellIterator.hasNext()){cell = cellIterator.next();cell.setCellType(Cell.CELL_TYPE_STRING);开关(cell.getCellType()){案例 Cell.CELL_TYPE_STRING:System.out.print(cell.getStringCellValue()+"|"​​);休息;案例 Cell.CELL_TYPE_NUMERIC:System.out.print(cell.getNumericCellValue()+"|"​​);休息;}}System.out.println();}

• 我的问题是:
  (1) 如何将记录放入数组或数组列表中?
  (2) 创建后，如何拆分|"?

解决方案

只需在第一个while之前创建一个List of List变量，在每次迭代开始时创建一个新的List，放入元素到此列表并在迭代结束时将此列表添加到主列表列表中.你应该得到这样的东西:

<预><代码>...列表<列表<字符串>>record = new ArrayList>();while(rowIterator.hasNext()){列表<字符串>record = new ArrayList();row = (XSSFRow)rowIterator.next();迭代器<Cell>cellIterator = row.cellIterator();while(cellIterator.hasNext()){cell = cellIterator.next();cell.setCellType(Cell.CELL_TYPE_STRING);开关(cell.getCellType()){案例 Cell.CELL_TYPE_STRING:record.add(cell.getStringCellValue());休息;案例 Cell.CELL_TYPE_NUMERIC:record.add(Double.toString(cell.getNumericCellValue()));休息;}}记录.添加(记录)；}for(列表<字符串>记录:记录){for (String s : 记录) {System.out.print(" " + s);}System.out.println();}...

另请注意，您不需要添加 |不再是符号，因此最终无需拆分.但通常要拆分字符串，有一个方法 String#split() 接受正则表达式.你需要像这样使用它来分割|"(您需要将 \ 放在 | 之前，因为它是一个特殊的正则表达式字符):

for(字符串记录:记录){System.out.println(记录);String[] 元素 = record.split("\\|");for(字符串元素:元素){System.out.println(" -> " + element);}}

• excel file (staff.xls)
  ID           name
  1             ali
  2             abu
  3             ahmad
  

• java code

  FileInputStream inputFile = new FileInputStream("staff.xls");
  XSSFWorkbook workbook = new XSSFWorkbook(inputFile);
  XSSFSheet spreadsheet = workbook.getSheetAt(0);
  XSSFRow row;
  Cell cell;
  
  Iterator<Row> rowIterator = spreadsheet.iterator();
  
  while(rowIterator.hasNext()){
       row = (XSSFRow)rowIterator.next();
  
       Iterator<Cell> cellIterator = row.cellIterator();
  
       while(cellIterator.hasNext()){
           cell = cellIterator.next();
           cell.setCellType(Cell.CELL_TYPE_STRING); 
  
       switch(cell.getCellType()){
           case Cell.CELL_TYPE_STRING:
              System.out.print(cell.getStringCellValue()+"|");
              break;
           case Cell.CELL_TYPE_NUMERIC:
              System.out.print(cell.getNumericCellValue()+"|");
              break;
           }
       }
  
       System.out.println();
  }
  

• My question is:
  (1) How to put the record into the array or arraylist?
  (2) After create, how to split the "|"?

解决方案

Just create a List of List variable before the first while, in the beginning of every iteration create a new List, put the elements to this list and add this list to the main List of Lists at the end of the iteration. You should get something like that:

...

List<List<String>> records = new ArrayList<List<String>>();

while(rowIterator.hasNext()){
    List<String> record = new ArrayList<String>();

    row = (XSSFRow)rowIterator.next();

    Iterator<Cell> cellIterator = row.cellIterator();

    while(cellIterator.hasNext()){
        cell = cellIterator.next();
        cell.setCellType(Cell.CELL_TYPE_STRING);

        switch(cell.getCellType()){
            case Cell.CELL_TYPE_STRING:
                record.add(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_NUMERIC:
                record.add(Double.toString(cell.getNumericCellValue()));
                break;
        }
    }

    records.add(record);
}

for (List<String> record : records) {
    for (String s : record) {
        System.out.print(" " + s);
    }

    System.out.println();
}

...

Also notice that you don't need to add | symbol anymore, so no need to split eventually. But in general to split the string there is a method String#split() which accepts a regular expression. You need to use it like that to split by "|" (you need to put \ before | as it is a special regexp character):

for (String record : records) {
    System.out.println(record);

    String[] elements = record.split("\\|");
    for (String element : elements) {
        System.out.println(" -> " + element);
    }
}

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