Java生成pdf文件或jpg图片的案例讲解

<parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-parent</artifactId>
 <version>2.1.4.RELEASE</version>
</parent>
<dependencies>
 <!-- freemarker -->
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-context-support</artifactId>
 </dependency>
 <dependency>
 <groupId>org.freemarker</groupId>
 <artifactId>freemarker</artifactId>
 </dependency>
 <!-- pdf核心包 -->
 <dependency>
 <groupId>com.itextpdf</groupId>
 <artifactId>itextpdf</artifactId>
 <version>5.5.12</version>
 </dependency>
 <!-- 适配中文字体 -->
 <dependency>
 <groupId>com.itextpdf</groupId>
 <artifactId>itext-asian</artifactId>
 <version>5.2.0</version>
 </dependency>
 <!-- html转pdf -->
 <dependency>
 <groupId>com.itextpdf.tool</groupId>
 <artifactId>xmlworker</artifactId>
 <version>5.5.12</version>
 </dependency>
 <!-- pdf转图片 -->
 <dependency>
 <groupId>org.apache.pdfbox</groupId>
 <artifactId>pdfbox</artifactId>
 <version>2.0.5</version>
 </dependency>
</dependencies>

@Data
public class GeneratePdfReq {
 /**
 * 生成pdf文件的绝对路径
 */
 @NotBlank(message = "生成pdf文件的绝对路径不能为空")
 @Pattern(regexp = "^.*(\\.pdf|\\.jpg)$", message = "生成的文件必须以.pdf或.jpg结尾")
 private String absolutePath;
 /**
 * 使用html模板的绝对路径
 */
 @NotBlank(message = "使用的模板路径不能为空")
 private String templateName;
 /**
 * 渲染模板的业务数据
 */
 private Object dataModel;
 /**
 * 水印信息
 */
 private WaterMarkInfo waterMarkInfo;
 /**
 * pdf文件的宽，默认A4
 */
 private float width = 595;
 /**
 * pdf文件的高，默认A4
 */
 private float height = 842;
}

@Data
public class WaterMarkInfo {
 /**
 * 如果为null设置水印时会报错
 */
 private String waterMark = "";
 /**
 * 水印透明度,值越小透明度越高
 */
 private float opacity = 0.2F;
 /**
 * 水印字体，如果乱码设置为本地宋体字体:fonts/simsun.ttc,1
 */
 private String fontName = "STSong-Light";
 /**
 * 水印编码格式，如果乱码设置为:BaseFont.IDENTITY_H
 */
 private String encoding = "UniGB-UCS2-H";
 /**
 * 字体大小
 */
 private float fontSize = 24;
 /**
 * 横坐标在页面宽度的百分比,左下角为原点
 */
 private float x = 50;
 /**
 * 纵坐标在页面高度的百分比,左下角为原点
 */
 private float y = 40;
 /**
 * 水印旋转角度
 */
 private float rotation = 45;
}

@Data
public class GeneratePdfResp {
 /**
 * 生成pdf的绝对路径
 */
 private String absolutePath;
}

@Service("freeMarkerService")
@Slf4j
public class FreeMarkerServiceImpl implements FreeMarkerService {
 @Autowired
 private FreeMarkerConfigurer freeMarkerConfigurer;
 /**
 * 渲染html后获取整个页面内容
 *
 * @param templatePath 模板路径
 * @param dataModel 业务数据，一般以map形式传入
 * @return
 */
 @Override
 public String getHtml(String templatePath, Object dataModel) {
 log.info("开始将模板{}渲染为html,业务数据{}", templatePath, JSONUtil.toJsonPrettyStr(dataModel));
 Configuration cfg = freeMarkerConfigurer.getConfiguration();
 cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER); // freemaker异常时仍旧抛出，统一异常处理
 cfg.setClassicCompatible(true);// 不需要对null值预处理，否则需要在模板取值时判断是否存在，不然报错
 StringWriter stringWriter = new StringWriter();
 try {
  // 设置模板所在目录，绝对路径方式，不打进jar包
//  cfg.setDirectoryForTemplateLoading(new File(templatePath).getParentFile());
//  Template temp = cfg.getTemplate(new File(templatePath).getName());
  // 相对路径设置模板所在目录，模板打进jar包，默认就是resources目录下的/templates目录。
  cfg.setClassForTemplateLoading(this.getClass(), "/templates");
  Template temp = cfg.getTemplate(templatePath);
  temp.process(dataModel, stringWriter);
 } catch (Exception e) {
  log.error(PdfErrorCode.PDF_TEMPLATE_RENDER_FAIL.getDesc(), e);
  throw new PdfBizException(PdfErrorCode.PDF_TEMPLATE_RENDER_FAIL);
 }
 return stringWriter.toString();
 }
}

@Service("pdfService")
@Slf4j
public class PdfServiceImpl implements PdfService {
 public static final String FONT_PATH = "fonts/simsun.ttc,1";
 @Autowired
 private WaterMarkerService waterMarkerService;
 /**
 * html页面内容转pdf，并给每页附上水印
 *
 * @param html  html页面内容
 * @param width  pdf的宽
 * @param height pdf的高
 * @param waterMarkInfo 水印信息
 * @return
 */
 @Override
 public byte[] html2Pdf(String html, float width, float height, WaterMarkInfo waterMarkInfo) {
 log.info("=================开始将html转换为pdf=================");
 ByteArrayOutputStream out = new ByteArrayOutputStream();
 this.html2Pdf(html, width, height, out);
 byte[] bytes = out.toByteArray();
 // 设置水印
 if (waterMarkInfo != null) {
  bytes = waterMarkerService.addWaterMarker(bytes, waterMarkInfo);
 }
 return bytes;
 }
 /**
 * html转pdf
 *
 * @param html html页面内容
 * @param width pdf的宽
 * @param height pdf的高
 * @param out 输出流，pdf文件用此流输出，需要pdf文档关闭后流中才会有数据
 */
 @Override
 @SneakyThrows
 public void html2Pdf(String html, float width, float height, OutputStream out) {
 @Cleanup Document document = new Document(new RectangleReadOnly(width, height)); // 默认A4纵向
 // 这里需要关闭document才能让生成的pdf字节数据刷到输出流中
 PdfWriter writer = PdfWriter.getInstance(document, out); // 关闭可能导致生成的pdf显示异常（Chrome）
 document.open();
 // 设置字体,这里统一用simsun.ttc即宋体
 XMLWorkerFontProvider asianFontProvider = new XMLWorkerFontProvider() {
  @Override
  public Font getFont(String fontname, String encoding, boolean embedded, float size, int style, BaseColor color, boolean cached) {
  Font font;
  try {
   font = new Font(BaseFont.createFont(FONT_PATH, BaseFont.IDENTITY_H, BaseFont.EMBEDDED));
  } catch (Exception e) {
   log.error(PdfErrorCode.SET_PDF_FONT_FAIL.getDesc(), e);
   throw new PdfBizException(PdfErrorCode.SET_PDF_FONT_FAIL);
  }
  font.setStyle(style);
  font.setColor(color);
  if (size > 0) {
   font.setSize(size);
  }
  return font;
  }
 };
 // 生成pdf
 try {
  XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(html.getBytes("UTF-8")), null, Charset.forName("UTF-8"), asianFontProvider);
  // 如果系统已经装有simsun.ttc字体，则不需要单独设置字体也不需要itext-asian jar包
//  XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(html.getBytes("UTF-8")), null, Charset.forName("UTF-8"));
 } catch (RuntimeWorkerException e) {
  log.error(PdfErrorCode.HTML_CONVERT2PDF_FAIL.getDesc(), e);
  throw new PdfBizException(PdfErrorCode.HTML_CONVERT2PDF_FAIL);
 }
 }
}

@Service("waterMarkerService")
@Slf4j
public class WaterMarkerServiceImpl implements WaterMarkerService {
 /**
 * 给pdf文件每页添加水印
 *
 * @param source pdf文件的字节数组形式
 * @param waterMarkInfo 水印信息
 * @return
 */
 @Override
 public byte[] addWaterMarker(byte[] source, WaterMarkInfo waterMarkInfo) {
 log.info("开始设置水印数据{}", JSONUtil.toJsonPrettyStr(waterMarkInfo));
 ByteArrayOutputStream out = new ByteArrayOutputStream();
 this.addWaterMarker(source, waterMarkInfo, out);
 return out.toByteArray();
 }
 /**
 * 给pdf文件每页添加水印
 *
 * @param source pdf文件的字节数组形式
 * @param waterMarkInfo 水印信息
 * @param out  输出流，pdf文件用此流输出，需要pdf文档关闭后流中才会有数据
 */
 @Override
 @SneakyThrows
 public void addWaterMarker(byte[] source, WaterMarkInfo waterMarkInfo, OutputStream out) {
 @Cleanup PdfReader reader = new PdfReader(source);
 // 这里需要关闭PdfStamper才能让生成的pdf字节数据刷到输出流中
 @Cleanup PdfStamper pdfStamper = new PdfStamper(reader, out);
 BaseFont font = BaseFont.createFont(waterMarkInfo.getFontName(), waterMarkInfo.getEncoding(), BaseFont.EMBEDDED);
 PdfGState gs = new PdfGState();
 gs.setFillOpacity(waterMarkInfo.getOpacity());
 // 给每页pdf生成水印
 for (int i = 1; i <= reader.getNumberOfPages(); i++) {
  PdfContentByte waterMarker = pdfStamper.getUnderContent(i);
  waterMarker.beginText();
  // 设置水印透明度
  waterMarker.setGState(gs);
  // 设置水印字体和大小
  waterMarker.setFontAndSize(font, waterMarkInfo.getFontSize());
  // 设置水印位置、内容、旋转角度
  float X = reader.getPageSize(i).getWidth() * waterMarkInfo.getX() / 100;
  float Y = reader.getPageSize(i).getHeight() * waterMarkInfo.getY() / 100;
  waterMarker.showTextAligned(Element.ALIGN_CENTER, waterMarkInfo.getWaterMark(), X, Y, waterMarkInfo.getRotation());
  // 设置水印颜色
  waterMarker.setColorFill(BaseColor.GRAY);
  waterMarker.endText();
 }
 }
}

@Slf4j
@Service("generatePdfService")
public class GeneratePdfServiceImpl implements RestService {
 @Autowired
 private FreeMarkerService freeMarkerService;
 @Autowired
 private PdfService pdfService;
 @Override
 @SneakyThrows
 public GeneratePdfResp service(GeneratePdfReq generatePdfReq) {
 log.info("开始生成pdf文件,请求报文:{}", JSONUtil.toJsonPrettyStr(generatePdfReq));
 /*
 1.根据freemarker模板填充业务数据获取完整的html字符串
  */
 String html = freeMarkerService.getHtml(generatePdfReq.getTemplateName(), generatePdfReq.getDataModel());
 /*
 2.生成pdf文件（内存）
  */
 byte[] bytes = pdfService.html2Pdf(html, generatePdfReq.getWidth(), generatePdfReq.getHeight(), generatePdfReq.getWaterMarkInfo());
 /*
 3.本地保存pdf文件
  */
 File targetFile = new File(generatePdfReq.getAbsolutePath());
 // 上级目录不存在则创建
 if (!targetFile.getParentFile().exists()) {
  targetFile.getParentFile().mkdirs();
 }
 // 根据不同文件名后缀生成对应文件
 if (generatePdfReq.getAbsolutePath().endsWith("pdf")) {
  FileUtils.writeByteArrayToFile(targetFile, bytes);
 } else {
  @Cleanup PDDocument document = PDDocument.load(bytes);
  PDFRenderer renderer = new PDFRenderer(document);
  BufferedImage bufferedImage = renderer.renderImageWithDPI(0, 150);// 只打第一页,dpi越大图片越高清也越耗时
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  ImageIO.write(bufferedImage, "jpg", baos);
  FileUtils.writeByteArrayToFile(targetFile, baos.toByteArray());
 }
 log.info("文件本地保存完成,文件路径:[{}]", targetFile.getAbsolutePath());
 /*
 4.组织返回
  */
 GeneratePdfResp generatePdfResp = new GeneratePdfResp();
 generatePdfResp.setAbsolutePath(targetFile.getAbsolutePath());
 return generatePdfResp;
 }
}

@Slf4j
@RestController
public class PdfController {
 @Autowired
 private RestService generatePdfService;
 @PostMapping(value = "/html2Pdf")
 public GeneratePdfResp html2Pdf(@RequestBody @Validated GeneratePdfReq req) {
 GeneratePdfResp resp = generatePdfService.service(req);
 return resp;
 }
}

<html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
 <meta http-equiv="Content-Style-Type" content="text/css"/>
 <style>
 body {
  font-family: SimSun
 }
 </style>
 <title>html模板</title>
</head>
<body>
<div>
 <p style="margin:0pt; orphans:0; text-align:center; widows:0">
 <span style="font-family:SimSun; font-size:16pt">html模板</span><br/>
 </p>
 <p>姓名：${name}</p>
 <p>证件号码：${cardNo}</p>
 <p>日期：${date}</p>
</div>
</body>
</html>