java实现图片格式转换(svg、png、webp)

2023-07-29 04:48| 来源: 网络整理| 查看: 265

文章目录一、svg文件1.1 svg介绍1.2 svg文件操作1.2.1 获取svg文件源码1.2.2 获取svg文件宽高1.2.3 获取svg文件颜色1.2.4 svg文件着色二、svg转png2.1 Batik介绍2.2 引入java batik依赖2.3 svg转png 三、png转jpg3.1 命令行转换3.2 第三方jar包转换3.2.1 导入maven依赖3.2.2 调用接口

一、svg文件 1.1 svg介绍

SVG 意为可缩放矢量图形（Scalable Vector Graphics），使用 XML 格式定义图像。因此对svg文件的操作，可以看做对xml文件的解析。svg基础知识可以参考svg教程，在此不做过多赘述。

1.2 svg文件操作 1.2.1 获取svg文件源码

读取svg文件并转换为字符串类型，可得到源码

public String svgOriginFile(MultipartFile file) throws IOException { if (file != null) { InputStream fileInput = file.getInputStream(); byte[] inputByte = new byte[fileInput.available()]; fileInput.read(inputByte); String originFile = new String(inputByte, "UTF-8"); log.info("Get svg originFile [{}]", originFile); fileInput.close(); return originFile; } return null; } 1.2.2 获取svg文件宽高

读取svg的xml文件，获取svg文件的width、height属性

public Float svgSize(String originFile, String lengthName) throws IOException { if (originFile != null && lengthName != null) { Document doc = svgDocument(originFile); Element element = doc.getDocumentElement(); String length = lengthReg(element.getAttribute(lengthName)); if (length == "" || length == null) { int num = lengthName.equals("width") ? 2 : 3; String viewBox = element.getAttribute("viewBox"); length = viewBox.split(" ")[num]; } log.info("Svg {} size is {}", lengthName, length); return Float.parseFloat(length); } return null; } public Document svgDocument(String originFile) throws IOException { byte[] bytes = originFile.getBytes("utf-8"); ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes); String parser = XMLResourceDescriptor.getXMLParserClassName(); SAXSVGDocumentFactory f = new SAXSVGDocumentFactory(parser); Document doc = f.createDocument(null, inputStream); return doc; } public String lengthReg(String str) { //用正则表达式 String reg = "[^0-9]"; //Pattern类的作用在于编译正则表达式后创建一个匹配模式. Pattern p = Pattern.compile(reg); //Matcher类使用Pattern实例提供的模式信息对正则表达式进行匹配 Matcher m = p.matcher(str); return m.replaceAll("").trim(); } 1.2.3 获取svg文件颜色

读取svg的xml文件，获取svg文件的fill属性

public String selectColorByOriginFile(String originFile) throws IOException { if (originFile != null) { Document doc = svgDocument(originFile); Element element = doc.getDocumentElement(); NodeList list = element.getElementsByTagName("path"); Element colorElement = (Element) list.item(0); String color = colorElement.getAttribute("fill"); log.info("Get svg color [{}]", color); return color; } return null; } 1.2.4 svg文件着色

读取svg的xml文件，更改svg文件的fill属性，写入xml文件

public String svgColoration(String originFile, String color) throws TransformerException, IOException { if (originFile != null && color != null) { Document doc = svgDocument(originFile); Element element = doc.getDocumentElement(); NodeList list = element.getElementsByTagName("path"); for (int i = 0; i batik.version} org.apache.xmlgraphics batik-transcoder ${batik.version} org.apache.xmlgraphics batik-codec ${batik.version} org.apache.xmlgraphics xmlgraphics-commons 2.3 2.3 svg转png

入参为svg源文件码

public InputStream svgToPng(String originFile, Float multiple) throws IOException, TranscoderException { if (originFile != null && multiple != null) { long st = System.currentTimeMillis(); ByteArrayOutputStream pngStream = new ByteArrayOutputStream(); InputStream pngInput; byte[] bytes = originFile.getBytes("utf-8"); TranscoderInput input = new TranscoderInput(new ByteArrayInputStream(bytes)); PNGTranscoder t = new PNGTranscoder(); //获取宽高，动态放大 Float width = svgSize(originFile, "width"); Float height = svgSize(originFile, "height"); t.addTranscodingHint(PNGTranscoder.KEY_WIDTH, width * multiple); t.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, height * multiple); //格式转换 t.transcode(input, new TranscoderOutput(pngStream)); byte[] outByte = pngStream.toByteArray(); pngInput = new ByteArrayInputStream(outByte); long cost = System.currentTimeMillis() - st; log.info("SvgToPng success, cost time {} ms", cost); pngStream.close(); return pngInput; } else { return null; } }

入参为svg文件

public static void convertToPngByFile(String filePath, String pngFilePath,Map map) throws IOException, TranscoderException { File file = new File(pngFilePath); FileOutputStream outputStream = null; try { file.createNewFile(); outputStream = new FileOutputStream(file); convertToPngByFile(filePath, outputStream,map); } finally { if (outputStream != null) { try { outputStream.close(); } catch (IOException e) { e.printStackTrace(); } } } } public static void convertToPngByFile(String path, OutputStream outputStream,Map map) throws TranscoderException, IOException { try { File file = new File(path); String parser = XMLResourceDescriptor.getXMLParserClassName(); SAXSVGDocumentFactory f = new SAXSVGDocumentFactory(parser); Document doc = f.createDocument(file.toURI().toString()); for (int i = 1; i if (outputStream != null) { try { outputStream.close(); } catch (IOException e) { e.printStackTrace(); } } } } } 三、png转jpg 3.1 命令行转换

cwebp [options] input_file -o output_file.webp

参考：

java服务器端图片转换webp以及批量转换webp脚本

cwebp 命令大全

官方文档

3.2 第三方jar包转换

webp-imageio

3.2.1 导入maven依赖

由于公司私服有该依赖，故无需手动下载引入依赖，手动导入方式可参考文末链接

com.github.nintha webp-imageio-core 0.1.3 3.2.2 调用接口 public void pngToWebp(InputStream pngInput, String outputWebpPath) throws IOException { if (pngInput == null && outputWebpPath == null) { return; } long st = System.currentTimeMillis(); BufferedImage image = ImageIO.read(pngInput); ImageWriter writer = ImageIO.getImageWritersByMIMEType("image/webp").next(); WebPWriteParam writeParam = new WebPWriteParam(writer.getLocale()); writeParam.setCompressionMode(writeParam.MODE_EXPLICIT); writeParam.setCompressionType("Lossless"); writer.setOutput(new FileImageOutputStream(new File(outputWebpPath))); writer.write(null, new IIOImage(image, null, null), writeParam); long cost = System.currentTimeMillis() - st; log.info("PngToWebp success, cost time {} ms", cost); }

参考：

官方文档

https://blog.csdn.net/xu_san_duo/article/details/79085718

https://www.jb51.net/article/147135.htm

https://segmentfault.com/a/1190000016324137

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