package vip.xiaonuo.modular.blogarticle;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.PdfCopy;
import com.itextpdf.text.pdf.PdfImportedPage;
import com.itextpdf.text.pdf.PdfReader;

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

/**
 * pdf 切割合并demo
 */
public class PdfUtils {

    public static void main(String args[]) throws IOException, DocumentException {
        try {
            //抽取页面

            splitPDF("D:\\inleft\\Redis开发与运维(付磊).pdf", "D:\\inleft\\redis-split-1.pdf",
                    28, 59);

//            splitPDF("D:\\桌面\\翻译任务\\IEC-61158-2-2003.pdf", "D:\\桌面\\翻译任务\\output1.pdf",
//                    231, 243);
//            splitPDF("D:\\桌面\\翻译任务\\IEC-61158-2-2003.pdf", "D:\\桌面\\翻译任务\\output2.pdf",
//                    260, 261);
//            //合并页面
//            String[] files = {"C:\\Users\\Administrator\\Desktop\\毕业设计.pdf", "C:\\Users\\Administrator\\Desktop\\毕业论文中期检查表.pdf"};
//            String savepath = "C:\\Users\\Administrator\\Desktop\\K.pdf";
//            mergePdfFiles(Arrays.asList(files), savepath);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    /**
     * 合并原pdf为新文件
     *
     * @param files   pdf绝对路径集
     * @param newfile 新pdf绝对路径
     * @return
     * @throws IOException
     * @throws DocumentException
     */
    public static void mergePdfFiles(List<String> files, String newfile) throws IOException, DocumentException {
        Document document = new Document(new PdfReader(files.get(0)).getPageSize(1));
        PdfCopy copy = new PdfCopy(document, new FileOutputStream(newfile));
        document.open();
        for (int i = 0; i < files.size(); i++) {
            PdfReader reader = new PdfReader(files.get(i));
            int n = reader.getNumberOfPages();
            for (int j = 1; j <= n; j++) {
                document.newPage();
                PdfImportedPage page = copy.getImportedPage(reader, j);
                copy.addPage(page);
            }
        }
        document.close();
    }

    public static void splitPDF(String bytes, String newFile, int start, int end) {
        Document document = null;
        PdfCopy copy = null;
        try {
            //源读取
            PdfReader reader = new PdfReader(bytes);
            //获取pdf页数
            int n = reader.getNumberOfPages();
            if (end == 0) {
                end = n;
            }

            document = new Document(reader.getPageSize(1));//读取源第一页
            copy = new PdfCopy(document, new FileOutputStream(newFile));//输出pdf初始化

            document.open();
            for (int j = start; j <= end; j++) {
                document.newPage();
                PdfImportedPage page = copy.getImportedPage(reader, j);//翻页到初始页
                copy.addPage(page);//输出文件追加内容
            }
            document.close();
        } catch (Exception e) {
            e.printStackTrace();
            System.err.println("split pdf file error:" + e.getMessage());
        }
    }

}