Java.lang.NoClassDefFoundError: org / fontbox / afm / FontMetric

J'utilise pdfbox-0.7.3.pot. Je sais que les fichiers de classe associés manquants appartiennent au JAR pdfbox-0.7.3 mais lorsque je joins le fichier source. continuez à montrer manquant .les fichiers de classe. je cherche des suggestions sur l'erreur ci-dessous.

    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import org.pdfbox.cos.COSDocument;
    import org.pdfbox.pdfparser.PDFParser;
    import org.pdfbox.pdmodel.PDDocument;
    import org.pdfbox.util.PDFTextStripper;
    import java.lang.NoClassDefFoundError;
    import java.util.Scanner;
        public class ggg{
        public static void main(String args[]) {
           // PDFTextStripper pdfStripper = null;
               // PDDocument pdDoc = null;
           // COSDocument cosDoc = null;
            File file = new File("C:\\Users\\firstfile.pdf");
            try {
                PDFParser parser = new PDFParser(new FileInputStream(file));
                parser.parse();
                COSDocument   cosDoc = parser.getDocument();
                PDFTextStripper   pdfStripper = new PDFTextStripper();
                PDDocument pdDoc = new PDDocument(cosDoc); 
                pdfStripper.setStartPage(1);
                pdfStripper.setEndPage(5);
                String parsedText = pdfStripper.getText(pdDoc);
                System.out.println(parsedText);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
        }
    }
Exception in thread "main" java.lang.NoClassDefFoundError: org/fontbox/afm/FontMetric
    at org.pdfbox.pdmodel.font.PDFont.getAFM(PDFont.java:334)
    at org.pdfbox.pdmodel.font.PDSimpleFont.getFontHeight(PDSimpleFont.java:104)
    at org.pdfbox.util.PDFStreamEngine.showString(PDFStreamEngine.java:336)
    at org.pdfbox.util.operator.ShowTextGlyph.process(ShowTextGlyph.java:80)
    at org.pdfbox.util.PDFStreamEngine.processOperator(PDFStreamEngine.java:452)
    at org.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:215)
    at org.pdfbox.util.PDFStreamEngine.processStream(PDFStreamEngine.java:174)
    at org.pdfbox.util.PDFTextStripper.processPage(PDFTextStripper.java:336)
    at org.pdfbox.util.PDFTextStripper.processPages(PDFTextStripper.java:259)
    at org.pdfbox.util.PDFTextStripper.writeText(PDFTextStripper.java:216)
    at org.pdfbox.util.PDFTextStripper.getText(PDFTextStripper.java:149)
    at ggg.main(ggg.java:30)