java 将excel文件转成png图片

要将Excel文件转换为PNG图片，你可以使用Java的Apache POI和Batik库。

1. 首先，使用POI库读取Excel文件的内容。你可以使用以下代码：

    FileInputStream fileInputStream = new FileInputStream("path/to/excel/file.xlsx");
    Workbook workbook = new XSSFWorkbook(fileInputStream);
    Sheet sheet = workbook.getSheetAt(0);

    int width = 0;
    int height = 0;

    for (Row row : sheet) {
        int rowHeight = sheet.getRow(row.getRowNum()).getHeight();
        height += rowHeight;
        for (Cell cell : row) {
            int columnWidth = sheet.getColumnWidth(cell.getColumnIndex());
            width += columnWidth;
        }
    }

    BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics2D graphics = bufferedImage.createGraphics();
    graphics.setPaint(Color.WHITE);
    graphics.fillRect(0, 0, width, height);
    graphics.translate(0, 0);

    sheet.draw(graphics);
    fileInputStream.close();

2. 接下来，使用Batik库将生成的BufferedImage转换为PNG格式。你可以使用以下代码：

    File file = new File("path/to/png/file.png");
    OutputStream outputStream = new FileOutputStream(file);

    PNGTranscoder pngTranscoder = new PNGTranscoder();
    TranscoderInput transcoderInput = new TranscoderInput(bufferedImage);
    TranscoderOutput transcoderOutput = new TranscoderOutput(outputStream);
    pngTranscoder.transcode(transcoderInput, transcoderOutput);

    outputStream.flush();
    outputStream.close();

以上就是把Excel文件转换为PNG图片的完整Java代码。