使用 Itext 生成PDF字節數組(文件流不落地)

package com.ulic.gis.customerCenter.controller;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.itextpdf.text.Document;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfWriter;
/**
 * 生成pdf字節數組
 * 將字節數組轉成pdf
 * 2019年7月12日
 */
@Controller
public class CreatePdfByte {
    private static final Logger log = LoggerFactory.getLogger(CreatePdfByte.class);
     /**
     *     生成pdf的字節數組
     */
    @RequestMapping(value="/generatePDF")
    public byte[] generatePDF() {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();//構建字節輸出流
        Document doc =null;

        try {

            doc = new Document(new Rectangle(PageSize.A4));// 可配其余4個參數，如（rectPageSize，60,60,60,60）頁面邊距
            PdfWriter.getInstance(doc,baos);//將PDF文檔對象寫入到流
            doc.open();  
            doc.add(new Paragraph("Hello World 啦啦啦 success!"));
            if(doc != null){
                doc.close();
            }
        }catch(Exception e) {
            log.error("PDF異常", e);
        }finally{
            if(baos != null){
                try {
                    baos.close();
                } catch (IOException e) {
                    log.error("PDF異常", e);
                }
            }
        }
        byte[] b = baos.toByteArray();//pdf字節數組
        System.out.println("baos.toByteArray().length:"+baos.toByteArray().length);
        return b;
    }
    /**
     * 將字節數組轉成pdf文件
     * @throws IOException
     */
    @RequestMapping(value="/array2pdf")
    public void array2pdf() throws IOException {
        System.out.println("開始生成pdf字節數組");
        
        byte[] b = generatePDF();
        
        String filename = "D:/testpdf/array2pdf.pdf";
         FileOutputStream fout = new FileOutputStream(filename);
            //將字節寫入文件
            fout.write(b);
            fout.close();
    }    
}