spring boot itextPdf根据模板生成pdf文件

摘要：在开发一些平台中会遇到将数据库中的数据渲染到模板文件中的场景，用完全动态生成文件的太过复杂，通过可以比较简单的完成数据渲染工作模板的表单域数据需定义名称获取输出流下载相关申请表下载设置响应设置响应文件名称申请表设置文件名称获取输出流

在开发一些平台中会遇到将数据库中的数据渲染到PDF模板文件中的场景，用itextPdf完全动态生成PDF文件的太过复杂，通过itextPdf/AcroFields可以比较简单的完成PDF数据渲染工作（PDF模板的表单域数据需定义名称）

Controller获取HttpServletResponse 输出流

package pdf.controller;

import com.itextpdf.text.DocumentException;
import service.PdfService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import java.io.IOException;
import java.io.OutputStream;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

@Controller
@RequestMapping(WebConstants.WEB_pdf + "/download")
@Api(description = "pdf下载相关", tags = "Pdf.download")
@NoAuth
public class PdfDownloadController {

    @Autowired
    private PdfService PdfService;
    
    @Value("${pdf.template.path}")
    private String templatePath ;

    @ApiOperation(value = "申请表下载")
    @RequestMapping(value = "/download/{id}", method = RequestMethod.GET)
    @ResponseBody 
    @NoLogin
    public void download(@PathVariable("id") Long id, HttpServletResponse response) throws IOException, DocumentException {
        
        //设置响应contenType
        response.setContentType("application/pdf");
        //设置响应文件名称
        String fileName = new String("申请表.pdf".getBytes("UTF-8"),"iso-8859-1");
        //设置文件名称
        response.setHeader("Content-Disposition", "attachment; filename="+fileName);
        //获取输出流
        OutputStream out = response.getOutputStream(); 
        PdfService.download(id, templatePath ,out);
    }
}

Service生成pdf数据响应输出流

1.业务service-负责实现获取pfd模板数据，数据库数据，实现动态赋值生成PDF

package service.impl;

import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.ResourceUtils;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.AcroFields;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;

@Service
public class ApplyServiceImpl implements ApplyService {

    @Override
    public DetailDTO getDetail(Long id) {
       // 获取业务数据
       return null;
    }
    
    @Override
    public Map getPdfMapping(DetailDTO dto) {
        // TODO Auto-generated method stub
        // 获取pdf与数据库的数据字段映射map
    }
    
    @Override
    public void download(Long id, String templatePath, OutputStream out) {
        // TODO Auto-generated method stub
        DetailDTO dto  =  getDetail(id);
        Map fieldMapping = getPdfMapping(dto);
        String filePath;
        byte[] pdfTemplate;
        ByteArrayOutputStream pdfOutputStream = new ByteArrayOutputStream();
        try {
            //获取模板文件路径
            filePath = ResourceUtils.getURL(templatePath).getPath();
            //获取模板文件字节数据
            pdfTemplate = IOUtils.toByteArray(new FileInputStream(filePath));
            //获取渲染数据后pdf字节数组数据
            byte[] pdfByteArray = generatePdfByTemplate(pdfTemplate, fieldMapping);
            pdfOutputStream.write(pdfByteArray);
            pdfOutputStream.writeTo(out);
            pdfOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                pdfOutputStream.close();
                out.flush();  
                out.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }  
        }

    }

    @Override
    //itextPdf/AcroFields完成PDF数据渲染
    public byte[] generatePdfByTemplate(byte[] pdfTemplate, Map pdfParamMapping) {
        Assert.notNull(pdfTemplate, "template is null");
        if (pdfParamMapping == null || pdfParamMapping.isEmpty()) {
            throw new IllegalArgumentException("pdfParamMapping can"t be empty");
        }

        PdfReader pdfReader = null;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PdfStamper stamper = null;
        try {
            // 读取pdf模板
            pdfReader = new PdfReader(pdfTemplate);
            stamper = new PdfStamper(pdfReader, baos);
            //获取所有表单字段数据
            AcroFields form = stamper.getAcroFields();
            form.setGenerateAppearances(true);

            // 设置
            ArrayList fontList = new ArrayList<>();
            fontList.add(getMsyhBaseFont());
            form.setSubstitutionFonts(fontList);

            // 填充form
            for (String formKey : form.getFields().keySet()) {
                form.setField(formKey, pdfParamMapping.getOrDefault(formKey, StringUtils.EMPTY));
            }
            // 如果为false那么生成的PDF文件还能编辑，一定要设为true
            stamper.setFormFlattening(true);
            stamper.close();
            return baos.toByteArray();
        } catch (DocumentException | IOException e) {
            LOGGER.error(e.getMessage(), e);
        } finally {
            if (stamper != null) {
                try {
                    stamper.close();
                } catch (DocumentException | IOException e) {
                    LOGGER.error(e.getMessage(), e);
                }
            }
            if (pdfReader != null) {
                pdfReader.close();
            }

        }
        throw new SystemException("pdf generate failed");
    }

    /**
     * 默认字体
     *
     * @return
     */
    private BaseFont getDefaultBaseFont() throws IOException, DocumentException {
        return BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
    }

    /**
     * 微软宋体字体
     *
     * @return
     */
     //设定字体
    private BaseFont getMsyhBaseFont() throws IOException, DocumentException {
        try {
            return BaseFont.createFont("/msyh.ttf", BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);
        } catch (DocumentException | IOException e) {
            LOGGER.error(e.getMessage(), e);
        }
        return getDefaultBaseFont();
    }
}

数据库的数据到pdf字段的映射可以使用配置，建立数据字段映射表，通过反射
可以将数据库数 据对象转为map，再通过定义的静态map映射表，将数据map转
换为pdf表单数据map

    BeanUtils.bean2Map(bean);
    /**
     * JavaBean对象转化成Map对象
     * @param javaBean
     * @return
     */
    public static Map bean2Map(Object javaBean) {
        Map map = new HashMap();

        try {
            // 获取javaBean属性
            BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());

            PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
            if (propertyDescriptors != null && propertyDescriptors.length > 0) {
                String propertyName = null; // javaBean属性名
                Object propertyValue = null; // javaBean属性值
                for (PropertyDescriptor pd : propertyDescriptors) {
                    propertyName = pd.getName();
                    if (!propertyName.equals("class")) {
                        Method readMethod = pd.getReadMethod();
                        propertyValue = readMethod.invoke(javaBean, new Object[0]);
                        map.put(propertyName, propertyValue);
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return map;
    }
    
    字段映射配置
    public class PdfMapping {

        public final static Map BASE_INFO_MAPPING = new HashMap() {
           {
            put("name", "partyA");
            put("identity", "baseIdentity");

           }
        };
    }