使用iText將多個pdf檔合併成一個pdf檔

範例如下，請參考：

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.PdfCopy;
import com.itextpdf.text.pdf.PdfSmartCopy;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Map;

public class mergePDF {
    public static void main(String args[]) throws IOException, DocumentException {
        //merge
        String[] files = {"filled_out_job_application.pdf", "replace_stream.pdf"};
        mergeFiles(files, "a.pdf", true);
        mergeFiles(files, "b.pdf", false);
    }

    public void mergeFiles(String[] files, String result, boolean smart) throws IOException, DocumentException {
        Document document = new Document();
        PdfCopy copy;
        if (smart)
            copy = new PdfSmartCopy(document, new FileOutputStream(result));
        else
            copy = new PdfCopy(document, new FileOutputStream(result));
        document.open();

        com.itextpdf.text.pdf.PdfReader[] reader = new com.itextpdf.text.pdf.PdfReader[3];
        for (int i = 0; i < files.length; i++) {
            reader[i] = new com.itextpdf.text.pdf.PdfReader(files[i]);
            copy.addDocument(reader[i]);
            copy.freeReader(reader[i]);
            reader[i].close();
        }
        document.close();
    }
}