先貼代碼,再解釋與疑問(這段代碼是我努力了半天的結(jié)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.獲得所有圖片---->
2.得到sheet DrawingPatriarch的所有shape--->
3.獲得shape的anchor --->
4.獲得picture的pictureIndex(這個(gè)很關(guān)鍵)------->
5.最后假定pictureIndex就是allPictures中圖片的位置,從而獲得這張picture的data信息.
問題:
對于最后的假定沒有官方文檔的支持,所以有待測試.但是簡單測試結(jié)果是ok的!
對于假定的證明:
官方文檔向excel添加圖片的流程是:
1.調(diào)用workbook的addPicture,并且返回此pictureIndex------>
2.然后創(chuàng)建一個(gè)ClientAnchor--------->
3.最后通過這個(gè)pictureIndex和Anchor把它繪到sheet上
由此可見pictureIndex,ClientAnchor以及pictureData是一一對應(yīng)的關(guān)系,只要能夠關(guān)聯(lián)這三者,就可以獲得
Excel中picture的完整信息了.
然而根據(jù)poi的api,只能單獨(dú)獲得picture,或者包含pictureIndex和anchor的HSSFPicture,并沒有把它們關(guān)聯(lián)在一起.
查看源碼發(fā)現(xiàn) HSSFWorkbook只不過是一個(gè)外觀類,或者適配器類,low level工作類為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);
- }
此處表明:如果能獲得InternalWorkbook對象和pictureIndex,就可以獲得圖片數(shù)據(jù)和信息.但是沒法通過 HSSFWorkbook對象獲得InternalWorkbook對象,因?yàn)槿缦?(此方法為包訪問)
- InternalWorkbook getWorkbook() {
- return workbook;
- }
但是觀察InternalWorkbook可以發(fā)現(xiàn),如圖:
- private List<EscherBSERecord> escherBSERecords;
保存圖像數(shù)據(jù)的底層是一個(gè)List有序的集合.以及根據(jù)getBSERecord方法,就推斷出picutreIndex就是表示picture在List里面的下標(biāo).
以上僅僅是個(gè)人的見解,由于對于poi的整體設(shè)計(jì)理念并沒有把握,所以對于以上問題暫時(shí)找不到?jīng)]有一個(gè)合理的解釋.