ObjectExtractor.java

package technology.tabula;

import java.io.IOException;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;

public class ObjectExtractor implements java.io.Closeable {

    private final PDDocument pdfDocument;

    private final List<String> tableNames;

    public ObjectExtractor(PDDocument pdfDocument, List<String> tableNames) {
        this.pdfDocument = pdfDocument;
        this.tableNames = tableNames;
    }

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - //
    protected Page extractPage(Integer pageNumber) throws IOException {
        if (pageNumber > pdfDocument.getNumberOfPages() || pageNumber < 1) {
            throw new java.lang.IndexOutOfBoundsException("Page number does not exist.");
        }
        PDPage page = pdfDocument.getPage(pageNumber - 1);
      
        ObjectExtractorStreamEngine streamEngine = new ObjectExtractorStreamEngine(page);
        streamEngine.processPage(page);

        TextStripper textStripper = new TextStripper(pdfDocument, pageNumber);
        textStripper.process();
        String tableName = "";
        //TODO 判断表名是否存在
        if (tableNames != null){
            //采用文本包含方式判断表名,后续需优化
            tableName = Utils.findTableName(tableNames, pdfTextStripper.getContent());
            if ("".equals(tableName)) {
                return null;
            }
        }
        Utils.sort(textStripper.getTextElements(), Rectangle.ILL_DEFINED_ORDER);

        float width, height;
        int rotation = page.getRotation();
        if (Math.abs(rotation) == 90 || Math.abs(rotation) == 270) {
            width = page.getCropBox().getHeight();
            height = page.getCropBox().getWidth();
        } else {
            width = page.getCropBox().getWidth();
            height = page.getCropBox().getHeight();
        }

        return Page.Builder.newInstance()
                .withPageDims(PageDims.of(0, 0, width, height))
                .withRotation(rotation)
                .withNumber(pageNumber)
                .withPdPage(page)
                .withPdDocument(pdfDocument)
                .withRulings(streamEngine.rulings)
                .withTextElements(textStripper.getTextElements())
                .withMinCharWidth(textStripper.getMinCharWidth())
                .withMinCharHeight(textStripper.getMinCharHeight())
                .withIndex(textStripper.getSpatialIndex())
                .withContent(pdfTextStripper.getContent())
                .withTableName(tableName)
                .build();
    }

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - //
    public PageIterator extract(Iterable<Integer> pages) {
        return new PageIterator(this, pages);
    }

    public PageIterator extract() {
        return extract(Utils.range(1, pdfDocument.getNumberOfPages() + 1));
    }

    public Page extract(int pageNumber) {
        return extract(Utils.range(pageNumber, pageNumber + 1)).next();
    }

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - //
    public void close() throws IOException {
        pdfDocument.close();
    }
    
}