先贴代码,再解释与疑问(这段代码是我努力了半天的结果)
- import java.io.FileInputStream;
- import java.io.FileOutputStream;
- import java.io.InputStream;
- import java.util.List;
-
- import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
- import org.apache.poi.hssf.usermodel.HSSFPicture;
- import org.apache.poi.hssf.usermodel.HSSFPictureData;
- import org.apache.poi.hssf.usermodel.HSSFShape;
- import org.apache.poi.hssf.usermodel.HSSFSheet;
- import org.apache.poi.hssf.usermodel.HSSFWorkbook;
- import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
- import org.apache.poi.ss.usermodel.PictureData;
- import org.apache.poi.ss.usermodel.WorkbookFactory;
-
- public class ReadPicturesFromExcel {
-
- public static void main(String[] args) throws InvalidFormatException,
- Exception {
-
- InputStream inp = new FileInputStream(
- "D:\\Users\\Fancy1_Fan\\桌面\\work\\test.xls");
- HSSFWorkbook workbook = (HSSFWorkbook) WorkbookFactory.create(inp);
-
- List<HSSFPictureData> pictures = workbook.getAllPictures();
- HSSFSheet sheet = (HSSFSheet) workbook.getSheetAt(0);
-
-
- int i = 0;
- for (HSSFShape shape : sheet.getDrawingPatriarch().getChildren()) {
- HSSFClientAnchor anchor = (HSSFClientAnchor) shape.getAnchor();
-
- if (shape instanceof HSSFPicture) {
- HSSFPicture pic = (HSSFPicture) shape;
- int row = anchor.getRow1();
- System.out.println(i + "--->" + anchor.getRow1() + ":"
- + anchor.getCol1());
- int pictureIndex = pic.getPictureIndex()-1;
- HSSFPictureData picData = pictures.get(pictureIndex);
-
- System.out.println(i + "--->" + pictureIndex);
- savePic(row, picData);
- }
- i++;
- }
- }
-
- private static void savePic(int i, PictureData pic) throws Exception {
-
- String ext = pic.suggestFileExtension();
-
- byte[] data = pic.getData();
- if (ext.equals("jpeg")) {
- FileOutputStream out = new FileOutputStream(
- "D:\\Users\\Fancy1_Fan\\桌面\\work\\pict" + i + ".jpg");
- out.write(data);
- out.close();
- }
- if (ext.equals("png")) {
- FileOutputStream out = new FileOutputStream(
- "D:\\Users\\Fancy1_Fan\\桌面\\work\\pict" + i + ".png");
- out.write(data);
- out.close();
- }
- }
-
- }
思路:
1.获得所有图片---->
2.得到sheet DrawingPatriarch的所有shape--->
3.获得shape的anchor --->
4.获得picture的pictureIndex(这个很关键)------->
5.最后假定pictureIndex就是allPictures中图片的位置,从而获得这张picture的data信息.
问题:
对于最后的假定没有官方文档的支持,所以有待测试.但是简单测试结果是ok的!
对于假定的证明:
官方文档向excel添加图片的流程是:
1.调用workbook的addPicture,并且返回此pictureIndex------>
2.然后创建一个ClientAnchor--------->
3.最后通过这个pictureIndex和Anchor把它绘到sheet上
由此可见pictureIndex,ClientAnchor以及pictureData是一一对应的关系,只要能够关联这三者,就可以获得
Excel中picture的完整信息了.
然而根据poi的api,只能单独获得picture,或者包含pictureIndex和anchor的HSSFPicture,并没有把它们关联在一起.
查看源码发现 HSSFWorkbook只不过是一个外观类,或者适配器类,low level工作类为InternalWorkbook
- /**
- * this is the reference to the low level Workbook object
- */
-
- private InternalWorkbook workbook;
查看InternalWorkbook有api如下
- public EscherBSERecord getBSERecord(int pictureIndex) {
- return escherBSERecords.get(pictureIndex-1);
- }
此处表明:如果能获得InternalWorkbook对象和pictureIndex,就可以获得图片数据和信息.但是没法通过 HSSFWorkbook对象获得InternalWorkbook对象,因为如下:(此方法为包访问)
- InternalWorkbook getWorkbook() {
- return workbook;
- }
但是观察InternalWorkbook可以发现,如图:
- private List<EscherBSERecord> escherBSERecords;
保存图像数据的底层是一个List有序的集合.以及根据getBSERecord方法,就推断出picutreIndex就是表示picture在List里面的下标.
以上仅仅是个人的见解,由于对于poi的整体设计理念并没有把握,所以对于以上问题暂时找不到没有一个合理的解释.
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