java后台将html转换为图片
方法一：利用springboot的freemark生成 要考虑样式兼容问题
1.pom引入对应的包
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-freemarkerartifactId>
dependency>
<dependency>
<groupId>com.openhtmltopdfgroupId>
<artifactId>openhtmltopdf-coreartifactId>
<version>0.0.1-RC9version>
dependency>
<repositories>
<repository>
<id>mvnrepositoryid>
<name>mvnrepositoryname>
<url>https://mvnrepository.comurl>
repository>
repositories>
2.对应的模板 后缀名.ft 文件
DOCTYPE html>
<html>
<head>
<meta charset="UTF-8"/>
<title>海报title>
head>
<body style="width: 500px; height: 800px;margin: 0;padding: 0;">
<span>${msg}span>
<img src="${img}" alt="" />
<div style="width: 100px;height: 100px;border-radius: 50%;background: rgba(255, 0, 0, 0.2);">大幅度发div>
body>
html>
3.工具类
public class FreemarkerUtils {
private static String getTemplate(String template, Map<String,Object> map) throws IOException, TemplateException {
Configuration cfg = new Configuration(Configuration.VERSION_2_3_25);
String templatePath = FreemarkerUtils.class.getResource("/").getPath()+"/templates";
cfg.setDirectoryForTemplateLoading(new File(templatePath));
cfg.setDefaultEncoding("UTF-8");
cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
cfg.setLogTemplateExceptions(false);
Template temp = cfg.getTemplate(template);
StringWriter stringWriter = new StringWriter();
temp.process(map, stringWriter);
stringWriter.flush();
stringWriter.close();
String resutl = stringWriter.getBuffer().toString();
return resutl;
}
public static void turnImage(String template, Map<String,Object> map, HttpServletResponse response) throws Exception {
String html = getTemplate(template, map);
byte[] bytes=html.getBytes();
ByteArrayInputStream bin=new ByteArrayInputStream(bytes);
DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
DocumentBuilder builder=factory.newDocumentBuilder();
Document document=builder.parse(bin);
Java2DRenderer renderer = new Java2DRenderer(document,600,800);
BufferedImage img = renderer.getImage();
response.setContentType("image/jpeg");
response.setDateHeader("expries", -1);
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");
//输出在页面
// ImageIO.write(img, "jpg", response.getOutputStream());
//指定下载路径
File file=new File("D:\\zhifu\\测试.jpg");
try {
ImageIO.write(img, "jpg", file);
}catch (Exception e){
e.printStackTrace();
}
}
}
测试方法
public void test(HttpServletResponse response) {
try {
Map<String,Object> map=new HashMap<>(16);
map.put("msg","html--生成图片测试22222");
map.put("img","https://upload-images.jianshu.io/upload_images/912344-3054132dd6939004.png?imageMogr2/auto-orient/strip|imageView2/1/w/300/h/240");
FreemarkerUtils.turnImage("demo.ftl",map,response);
} catch (Exception e) {
e.printStackTrace();
}
}
第二种 将页面代码生成html在进行转化
public class PictureHtml {
public static void main(final String[] args) throws Exception {
//html页面中需要灵活变动的值
String headurl = "";//图片的路径不能是带有参数的 不然解析不了
String proUrl = "";
String qrCodeUrl = "";
String proName="犀牛皮特质皮鞋";
String proPrice="1000.00";
String userName="测试";
String html =
"\n" +
"\n" +
"\n" +
" \n" +
" \n" +
" 分享 \n" +
" \n" +
"\n" +
"\n" +
" \n" +
" \n" +
" \n" +
" ![](\""</span)
+headurl+"\"/>\n" +
" \n" +
" "+userName+"，为您安利好物\n" +
" \n" +
" \n" +
" +proUrl+"\"/>\n" +
" \n" +
" ¥"+proPrice+"\n" +
" "+proName+"\n" +
" \n" +
" +qrCodeUrl+"\"/>\n" +
" \n" +
" 识别小程序码，查看商品详情\n" +
" \n" +
"\n" +
"";
//string转为inputstream流
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(html.getBytes());
File targetFile = ResourceUtils.getFile(ResourceUtils.CLASSPATH_URL_PREFIX+"share1.html");
//inputstream流转为file
FileUtils.copyInputStreamToFile(byteArrayInputStream, targetFile);
//通过openhtmltopdf工具生成图片
final Java2DRenderer renderer = new Java2DRenderer(targetFile, 740, 1000);
final BufferedImage img = renderer.getImage();
final FSImageWriter imageWriter = new FSImageWriter();
imageWriter.setWriteCompressionQuality(1.0f);
imageWriter.write(img, "D:\\zhifu\\ccc.jpg");//输出路径
System.out.println("Done with rendering");
}
}