將HashMap寫入Excel

Question

我的要求是使用Apache POI將HashMap寫入excel，hashmap中的鍵是我的cell-id，hashmap中的值是要設置到該單元格中的值。 下面是我的代碼：

public static final String[] ExcelColumns = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", 
    "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "AA", "AB", "AC", "AD", "AE", "AF", "AG", "AH", "AI", 
    "AJ", "AK", "AL", "AM", "AN", "AO", "AP", "AQ", "AR", "AS", "AT", "AU", "AV", "AW", "AX", "AY", "AZ", "BA", 
    "BB", "BC", "BD", "BE", "BF", "BG", "BH", "BI", "BJ", "BK", "BL", "BM", "BN", "BO", "BP", "BQ", "BR", "BS", 
    "BT", "BU", "BV", "BW", "BX", "BY", "BZ", "CA", "CB", "CC", "CD", "CE", "CF", "CG", "CH", "CI", "CJ", "CK", "CL", "CM", 
    "CN", "CO", "CP", "CQ", "CR", "CS", "CT", "CU", "CV", "CW", "CX", "CY", "CZ", "DA", "DB", "DC", "DD", "DE", "DF", "DG", 
    "DH", "DI", "DJ", "DK", "DL", "DM", "DN", "DO", "DP", "DQ", "DR", "DS", "DT", "DU", "DV", "DW", "DX", "DY", "DZ"}; 

public static int row(Map.Entry pair) { 
     //System.out.println("The row is:"+k); 
     return new Integer(pair.getKey().toString().substring(1)); 
       } 
public static int column(Map.Entry pair) { 
     String indexVal = pair.getKey().toString().substring(0, 1); 
     String[] ExcelColumns = CompareExcelDAO.ExcelColumns; 
     int index = 0; 
     for (int i = 0; i < ExcelColumns.length; ++i) { 
       if (indexVal.equals(ExcelColumns[i])) { 
        index = i; 
       } 
     } 
     return index+1; 
    } 
public void CopyContentsOfExcel(HSSFWorkbook workbook, HSSFSheet sheet, 
       String ExcelPath_1, int i, HashMap getMismatchMap) 
       throws IOException {   
     int rownum = sheet.getLastRowNum()+2; // to check last used row in Excel    
     //CompareExcelDAO mapDao = new CompareExcelDAO(); 
       Iterator it1 = getMismatchMap.entrySet().iterator(); 
       while (it1.hasNext()) { 
        Map.Entry pair = (Map.Entry) it1.next(); 
        int r = row(pair) + rownum; 
        int c= column(pair); 
        System.out.println("c = "+c+"  r = "+r); 
        System.out.println("Key: "+pair.getKey()+" "+"Value: "+pair.getValue()); 
        sheet.createRow(r).createCell(c).setCellValue(pair.getValue().toString()); 

       }} 

的問題是它的打印只有一對鍵/值的成兩個固定的細胞，在調試模式下然而按預期當我只打開片顯示了所有行/列的值打印一個值。 http://www.tagwith.com/question_1103031_printing-a-hashmap-to-excel-using-jxl-api，本網站提供了一種使用jxl將Hashmap寫入Excel的方式，但是我的所有項目都使用Apache POI。

Answer 1

如果你想比較兩個擅長寫在第三個區別， 創建一個新的工作簿和表，並傳遞給方法，你可以打開你的兩個過人之處，比較類似如下：

while (file1cellIterator.hasNext()&& file2cellIterator.hasNext()) { 
       Cell file1cell = (Cell) file1cellIterator.next(); 
       Cell file2cell = (Cell) file2cellIterator.next(); 

       org.apache.poi.ss.usermodel.Cell cell = row.createCell(cellnum++); 

       switch (file1cell.getCellType()) { 
       case Cell.CELL_TYPE_BOOLEAN: 
        if ((file1cell.getBooleanCellValue())==(file2cell.getBooleanCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getBooleanCellValue()); 
          } 
        else if((file1cell.getBooleanCellValue())!=(file2cell.getBooleanCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getBooleanCellValue()); 
        } 
        break; 
       case Cell.CELL_TYPE_NUMERIC: 
        if ((file1cell.getNumericCellValue())==(file2cell.getNumericCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getNumericCellValue()); 
                 } 
        else if((file1cell.getNumericCellValue())!=(file2cell.getNumericCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue((file1cell.getNumericCellValue())-(file2cell.getNumericCellValue())); 
               } 
        break; 
       case Cell.CELL_TYPE_STRING: 
        if ((file1cell.getStringCellValue())==(file2cell.getStringCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue(file1cell.getStringCellValue()); 
          } 
        else if((file1cell.getStringCellValue())!=(file2cell.getStringCellValue())){ 
         ((org.apache.poi.ss.usermodel.Cell) cell).setCellValue((file1cell.getStringCellValue())+(file2cell.getStringCellValue())); 
        } 
        break; 
       default: 
        ((org.apache.poi.ss.usermodel.Cell) cell) 
          .setCellValue(file1cell.getStringCellValue()); 
        break; 
       } 
      } 
     } 

Answer 2

我不知道你怎麼可以有一個hashmap的多行。我有類似的問題，我做了以下。我將創建一個地圖，它將像ColumnName和ColumnValue那樣，我將它添加到多個列的地圖中。然後類似的很多行映射到List，我會寫它的Excel文件。你可以試試這個。

public static void main(String[] p) throws Exception{ 
    List<Map<String, String>> collection = new ArrayList<>(); 
    Map<String, String> row1 = new LinkedHashMap<>(); 
    row1.put("ID","1"); 
    row1.put("Name","pop"); 
    collection.add(row1); 
    Map<String, String> row2 = new LinkedHashMap<>(); 
    row2.put("ID","2"); 
    row2.put("Name","lop"); 
    collection.add(row2); 
    writeCollection(new File("excel1.xlsx"),"sheet1",collection); 
} 

private static void writeCollection(File file, String sheetName, List<Map<String, String>> collection) throws Exception { 
    try { 
     FileInputStream fileInputStream = new FileInputStream(file); 
     XSSFWorkbook workBook = new XSSFWorkbook(fileInputStream); 
     XSSFSheet sheet = workBook.getSheet(sheetName); 
     int rows = sheet.getLastRowNum(); 
     fileInputStream.close(); 
     rows = rows + 1; 

     for (int index = 0; index < collection.size(); index++) { 
      XSSFRow row = sheet.createRow(rows++); 
      Map<String, String> rowObject = collection.get(index); 
      for (String columnName : rowObject.keySet()) { 
       int cellIndex = getColumnIndex(sheet, columnName); 
       if (cellIndex != -1) { 
        XSSFCell cell = row.createCell(cellIndex); 
        cell.setCellValue(rowObject.get(columnName)); 
       } 
      } 
     } 
     FileOutputStream out = new FileOutputStream(file); 
     workBook.write(out); 
     out.close(); 

    } catch (Exception e) { 
     throw e; 
    } 
} 

public static int getColumnIndex(XSSFSheet sheet, String columnName) { 
    int columnIndex = -1; 
    try { 
     int colNum = sheet.getRow(0).getLastCellNum(); 
     XSSFRow firstRow = sheet.getRow(0); 
     for (int colIndex = 0; colIndex < colNum; colIndex++) { 
      XSSFCell cell = firstRow.getCell(colIndex); 
      if (cell.toString().equals(columnName)) { 
       columnIndex = colIndex; 
      } 
     } 
    } catch (Exception e) { 
     throw e; 
    } 
    return columnIndex; 
}