问不能导入jar？

EN

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

error has occured cannot find org.apache.pdfbox

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

/**
 * This will create a blank PDF and write the contents to a file.
  */
public class CreateBlankPDF
{

/**
 * This will create a blank PDF and write the contents to a file.
 *
 * @param file The name of the file to write to.
 *
 * @throws IOException If there is an error writing the data.
 * @throws COSVisitorException If there is an error while generating the document.
 */
public void create( String file ) throws IOException, COSVisitorException
{
    PDDocument document = null;
    try
    {
        document = new PDDocument();
        //Every document requires at least one page, so we will add one
        //blank page.
        PDPage blankPage = new PDPage();
        document.addPage( blankPage );
        document.save( file );
    }
    finally
    {
        if( document != null )
        {
            document.close();
        }
    }
}

/**
 * This will create a blank document.
 *
 * @param args The command line arguments.
 *
 * @throws IOException If there is an error writing the document data.
 * @throws COSVisitorException If there is an error generating the data.
 */
public static void main( String[] args ) throws IOException, COSVisitorException
{
    if( args.length != 1 )
    {
        usage();
    }
    else
    {
        CreateBlankPDF creator = new CreateBlankPDF();
        creator.create( args[0] );
    }
}

/**
 * This will print the usage of this class.
 */
private static void usage()
{
    System.err.println( "usage: java org.apache.pdfbox.examples.pdmodel.CreateBlankPDF <outputfile.pdf>" );
}