java springBoot整合freemarker,ftl输出html文本，转图片流

一、引入freemarker maven依赖

org.springframework.boot

spring-boot-starter-freemarker

二、在项目resources目录下就可以创建以ftl结尾的引擎模板啦

 WHImgShare.ftl 内容如下

三、定义接口

public interface IFreemarkerService {

/**

* @Description: 模板生成

* @data: [model, templatePath]

* @return: java.lang.String

* @Date: 2023-03-65 10:12:26

*/

String shareInfoToHtml(Map model,String templatePath);

}

import freemarker.template.Configuration;

import freemarker.template.Template;

import lombok.extern.slf4j.Slf4j;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;

import java.util.Map;

@Service

@Slf4j

public class FreemarkerServiceImpl implements IFreemarkerService {

@Autowired

Configuration configuration;

/**

* @param model

* @param templatePath

* @Description: 模板生成

* @data: [model, templatePath]

* @return: java.lang.String

* @Date: 2023-03-65 10:12:26

*/

@Override

public String shareInfoToHtml(Map model, String templatePath) {

Template template = null;

try {

template = configuration.getTemplate(templatePath);

return FreeMarkerTemplateUtils.processTemplateIntoString(template, model);

} catch (Exception e) {

log.info("Freemarker模板渲染视图失败"+e.getMessage());

}

return "";

}

}

四、业务调用

// 传入数据modelMap + 模板名称

String html = iFreemarkerService.shareInfoToHtml(modelMap, "/WHImgShare.ftl");

public class ImageUtil {

/**

* @Description: html转图片

* @data: [html, width, height] html字符串、宽、高

* @return: java.awt.image.BufferedImage

* @Date: 2023-03-65 14:09:57

*/

public static BufferedImage turnImage(String html, Integer width, Integer height) throws Exception {

// 转文档

byte[] bytes=html.getBytes();

ByteArrayInputStream bin = new ByteArrayInputStream(bytes);

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

DocumentBuilder builder = factory.newDocumentBuilder();

Document document = builder.parse(bin);

/*

画笔生成图

*/

DOMAnalyzer da = new DOMAnalyzer(document);

// 创建一个字节流

InputStream is = new ByteArrayInputStream(html.getBytes(StandardCharsets.UTF_8));

DocumentSource docSource = new StreamDocumentSource(is, null, "text/html; charset=utf-8");

// 设置样式属性

da.attributesToStyles();

da.addStyleSheet(null, CSSNorm.stdStyleSheet(), DOMAnalyzer.Origin.AGENT);

da.addStyleSheet(null, CSSNorm.userStyleSheet(), DOMAnalyzer.Origin.AGENT);

da.addStyleSheet(null, CSSNorm.formsStyleSheet(), DOMAnalyzer.Origin.AGENT);

da.getStyleSheets();

// 转图片

GraphicsEngine contentCanvas = new GraphicsEngine(da.getRoot(), da, docSource.getURL());

contentCanvas.createLayout(new Dimension(width, height));

// contentCanvas.setSize(width, height);

contentCanvas.setUseKerning(false);

contentCanvas.setAutoSizeUpdate(false);

contentCanvas.getConfig().setClipViewport(false);

contentCanvas.getConfig().setLoadImages(true);

contentCanvas.getConfig().setLoadBackgroundImages(true);

// 生成图片

BufferedImage img = contentCanvas.getImage();

//图片裁剪(移除白边)

Rectangle bounds = getBounds(img, Color.WHITE);

//输出当前图片宽高

BufferedImage cutBufferedImage = img.getSubimage(bounds.x, bounds.y, bounds.width, bounds.height);

// final FSImageWriter imageWriter = new FSImageWriter();

// imageWriter.setWriteCompressionQuality(0.0f);

// // 生成图片名字

// String uuid = UUID.randomUUID().toString();

// //输出路径

// imageWriter.write(bufferedImage, "D:\\img\\" + uuid + ".png");

return bufferedImage;

}

public static MultipartFile bufferedImageToMultipartFile(BufferedImage bufferedImage,String filename,String originalFilename){

//创建一个ByteArrayOutputStream

ByteArrayOutputStream os = new ByteArrayOutputStream();

try {

//把BufferedImage写入ByteArrayOutputStream

ImageIO.write(bufferedImage, "jpg", os);

//ByteArrayOutputStream转成InputStream

InputStream input = new ByteArrayInputStream(os.toByteArray());

//InputStream转成MultipartFile

return new MockMultipartFile(filename, originalFilename, ContentType.IMAGE_JPEG.toString(), input);

} catch (IOException e) {

log.info("BufferedImageToMultipartFile error:"+e.getMessage());

}

return null;

}

/**

* @Description: 图片裁剪

* @data: [img, fillColor] 图像、颜色

* @return: java.awt.Rectangle

* @Date: 2023-03-66 10:20:09

*/

public static Rectangle getBounds(BufferedImage img, Color fillColor) {

int top = getYInset(img, 20, 0, 1, fillColor);

int bottom = getYInset(img, 20, img.getHeight() - 10, -1, fillColor);

int left = getXInset(img, 10, top, 1, fillColor);

int right = getXInset(img, img.getWidth() - 40, top, -1, fillColor);

return new Rectangle(left, top, right - left, bottom - top);

}

public static int getYInset(BufferedImage img, int x, int y, int step, Color fillColor) {

while (new Color(img.getRGB(x, y), true).equals(fillColor)) {

y += step;

}

return y;

}

public static int getXInset(BufferedImage img, int x, int y, int step, Color fillColor) {

while (new Color(img.getRGB(x, y), true).equals(fillColor)) {

x += step;

}

return x;

}

/**

* 模拟 http post请求

*

* @param httpUrl

* @return

* @throws IOException

*/

public static InputStream dowloadFile(String httpUrl) throws IOException {

URL url = null;

try {

url = new URL(httpUrl);

} catch (MalformedURLException e1) {

e1.printStackTrace();

}

URLConnection conn = url.openConnection();

InputStream inStream = conn.getInputStream();

return inStream;

}

/**

* 读取字节输入流内容

*

* @param is

* @return

*/

public static byte[] readInputStream(InputStream is) {

ByteArrayOutputStream writer = new ByteArrayOutputStream();

byte[] buff = new byte[1024 * 2];

int len = 0;

try {

while ((len = is.read(buff)) != -1) {

writer.write(buff, 0, len);

}

is.close();

} catch (IOException e) {

e.printStackTrace();

}

return writer.toByteArray();

}

}

文章链接

 您阅读本篇文章共花了：