Tutorial sobre como gerar um PDF

Salve Galera…
Estava tentando executar um tutorial aqui do PJ sobre como gerar um PDF.
e ele está dando o seguinte erro:

java.lang.Error: Unresolved compilation problems:
Document cannot be resolved or is not a type
Document cannot be resolved or is not a type
PdfWriter cannot be resolved
Paragraph cannot be resolved or is not a type
DocumentException cannot be resolved or is not a type

at Chap0101.main(Chap0101.java:24)</blockquote>

o código é:

import java.io.FileOutputStream;
import java.io.IOException;

import com.lowagie.text.*;
import com.lowagie.text.pdf.PdfWriter;

public class Chap0101 {

    public static void main(String[] args) {

        System.out.println("Chapter 1 example 1: Hello World");

        // step 1: creation of a document-object
        Document document = new Document();

        try {

            // step 2:
            // we create a writer that listens to the document
            // and directs a PDF-stream to a file

            PdfWriter.getInstance(document, new
FileOutputStream("Chap0101.pdf"));

            // step 3: we open the document
            document.open();

            // step 4: we add a paragraph to the document
            document.add(new Paragraph("Hello World"));

        }
        catch(DocumentException de) {
            System.err.println(de.getMessage());
        }
        catch(IOException ioe) {
            System.err.println(ioe.getMessage());
        }

        // step 5: we close the document
        document.close();
    }
}

No mais é só!