如何使工作簿（输出流）将所有行写入 xlsx 文件而不是仅一行？

Question

I am still working on my file reading program but I have some problem with my code. A class 'file rating' will read all files in a directory and give them a rating. All the values are given to my 'sheetWriter class', which u can see down here. The class gets the correct values if I print the 'obj' (objects) but writing them to an excel is not working properly --> it will only write two rows: row 1 (the "Reachable for user", "Rating", "File path", and etc.) and row 2: ( reachable, 45, C://blabla, etc...). So it basically writes only one file to the xlsx. How Can I make it work so it writes all files to the xlsx?

Thanks! (I am a Java rookie)

public class SheetWriter {

private XSSFWorkbook workbook;
private XSSFSheet sheet;

//!! Maybe important to know: the values come from a for-loop
//from another class 'file rating': For (x : sourcefiles){ points=5  setPoints(points)  }    

public void SheetWriter(String file,String reachable, int points,String filePath,String fileName,String keywordMatch,String grootte, 
        String resolutie, String crea_date,String crea_mod,String last_acc, String authorString,String datetakenString,
        String manufactString,String modelString,String gps ) {

workbook = new XSSFWorkbook(); 
sheet = workbook.createSheet("Rating Files");

Map<String, Object[]> data = new TreeMap<String, Object[]>(); 
    data.put("1", new Object[]{"Reachable for user", "Rating", "File path","File name","Keyword","Size","Dimensions","Date_crea","Date_mod","Date_last_access",
    "Author","Date taken","Camera maker","Camera model","GPS-data"});

data.put(file, new Object[]{reachable, points,filePath,fileName,keywordMatch,grootte, resolutie, crea_date,crea_mod,last_acc,
             authorString,datetakenString,manufactString,modelString,gps});

Set<String> keyset = data.keySet(); 
    int rownum = 0; 
    for (String key : keyset) { 
        // this creates a new row in the sheet 
        Row row = sheet.createRow(rownum++);
        Object[] objArr = data.get(key); 
        int cellnum = 0;
        for (Object obj : objArr) { 
            // this line creates a cell in the next column of that row
            Cell cell = row.createCell(cellnum++);
            //System.out.println(obj);
            if (obj instanceof String) 
                cell.setCellValue((String)obj);
            else if (obj instanceof Integer) 
                cell.setCellValue((Integer)obj); 
        }

    }  //!! so here it's still OK. I can print all the obj (objects)

try { 
        sheet.autoSizeColumn(0);sheet.autoSizeColumn(1);sheet.autoSizeColumn(2);sheet.autoSizeColumn(3);
        sheet.autoSizeColumn(4);sheet.autoSizeColumn(5);sheet.autoSizeColumn(6);sheet.autoSizeColumn(7);
        sheet.autoSizeColumn(8);sheet.autoSizeColumn(9);sheet.autoSizeColumn(10);sheet.autoSizeColumn(11);
        sheet.autoSizeColumn(12);sheet.autoSizeColumn(13);sheet.autoSizeColumn(14);
         FileOutputStream out = new FileOutputStream(new File("C:/Users/user/Pictures/test.xlsx")); 
         workbook.write(out);  //!! Only writes one file to xlsx 
         out.close(); 
         workbook.close();
         System.out.println("test.xlsx is finished."); 

    } 
    catch (Exception e) { 
        e.printStackTrace(); 
    }

Answer 1

If you want to write several rows into a sheet and the result is only one row, then you likely have a problem with a counter variable not getting properly incremented or every iteration doing exactly the same.

This time, it's slightly different because you are writing (creating and setting a value) rows in an enhanced for loop relying on the keySet of a Map with two entries only.

That means you always write those two entries only .

The problem that not all the files are written may be caused by an issue in an outer loop. I suggest to pass an argument List<String> fileNames instead of String fileName and do the writing for all the files in this method. Otherwise check the outer loop.