Java HTML转图片（FreeMarker + html2img）

引入pom.xml依赖。

    gui.ava
    html2image
    2.0.1


    org.springframework.boot
    spring-boot-starter-freemarker

在【resources】目录下，创建一个文件夹【templates】并在该目录下创建一个ftl文件。

demo.ftl文件内容：

    
    



    

        
药品名称
        
类型
    
    

        
${name}
        
${type}
    

写一个Html转换工具类。

import freemarker.template.Configuration;
import freemarker.template.TemplateException;
import gui.ava.html.Html2Image;
import gui.ava.html.renderer.ImageRenderer;
import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;


public class HtmlConvertImgHelper {
    Configuration configuration;

    
    public HtmlConvertImgHelper() {
        if (configuration == null) {
            configuration = BeanHelper.getBean(Configuration.class);
        }
    }

    
    public byte[] htmlConvertImg(String fileName, Object map, String formatType) throws IOException, TemplateException {
        String htmlText = FreeMarkerTemplateUtils.processTemplateIntoString(configuration.getTemplate(fileName), map);
        return htmlConvertImg(htmlText, formatType);
    }

    
    public byte[] htmlConvertImg(String htmText, String formatType) throws IOException {
        //最终返回的byte流
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        Html2Image html2Image = Html2Image.fromHtml(htmText);
        ImageRenderer imageRenderer = html2Image.getImageRenderer();
        BufferedImage grayPicture = imageRenderer.getBufferedImage(BufferedImage.TYPE_INT_RGB);
        ImageIO.write(grayPicture, formatType, byteArrayOutputStream);
        return byteArrayOutputStream.toByteArray();
    }
}

写测试类测试功能是否可用。

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@RunWith(SpringRunner.class)
@Slf4j
public class Test {
   @org.junit.Test
    public void ccc() throws IOException, TemplateException {
        Map map = new HashMap<>();
        map.put("name", "鹤顶红");
        map.put("type", "毒药");
    
        byte[] bytes = new HtmlConvertImgHelper().htmlConvertImg("demo.ftl", map, "png");
        OutputStream os = new FileOutputStream("G:/text.png");
        os.write(bytes, 0, bytes.length);
        os.flush();
        os.close();
    }
}