前言

Webp是Google推出的一种新型图片格式，相比于 传统的PNG/JPG图片有着更小体积的优势，在Web中有着广泛的应用。由于Webp格式推出比较晚， Jdk 内置的图片编解码库对此并不支持。

网上给出的Java环境解决方案往往需要手动在java.library.path中安装对应的动态链接库，windows是dll文件，linux是so文件。这对于开发部署非常不方便。

本文提供一种无需手动安装动态链接库，同时可以方便处理Webp的解决方案

准备

先从github上面下载所需要的jar包

  webp-imageio-core-0.1.0.jar 

由于这个项目并未发布到maven中央仓库，所以需要手动导入本地jar包.

如果你用的是gradle，可以把jar包放入src/main/resource/libs目录，并在build.gradle中加入依赖

dependencies {
    compile fileTree(dir:'src/main/resources/libs',include:['*.jar'])
}

如果你用的是maven，可以把jar包放入${project.basedir}/libs目录，并在pom.xml中加入依赖

<dependency>  
    <groupId>com.github.nintha</groupId>  
    <artifactId>webp-imageio-core</artifactId>  
    <version>{versoin}</version>  
    <scope>system</scope>  
    <systemPath>${project.basedir}/libs/webp-imageio-core-{version}.jar</systemPath>  
</dependency>

例子

完整代码见 https://github.com/nintha/web...，以下为部分摘录

Webp编码

public static void main(String args[]) throws IOException {
    String inputPngPath = "test_pic/test.png";
    String inputJpgPath = "test_pic/test.jpg";
    String outputWebpPath = "test_pic/test_.webp";

    // Obtain an image to encode from somewhere
    BufferedImage image = ImageIO.read(new File(inputJpgPath));

    // Obtain a WebP ImageWriter instance
    ImageWriter writer = ImageIO.getImageWritersByMIMEType("image/webp").next();

    // Configure encoding parameters
    WebPWriteParam writeParam = new WebPWriteParam(writer.getLocale());
    writeParam.setCompressionMode(WebPWriteParam.MODE_DEFAULT);

    // Configure the output on the ImageWriter
    writer.setOutput(new FileImageOutputStream(new File(outputWebpPath)));

    // Encode
    writer.write(null, new IIOImage(image, null, null), writeParam);
}

Webp解码

public static void main(String args[]) throws IOException {
    String inputWebpPath = "test_pic/test.webp";
    String outputJpgPath = "test_pic/test_.jpg";
    String outputJpegPath = "test_pic/test_.jpeg";
    String outputPngPath = "test_pic/test_.png";

    // Obtain a WebP ImageReader instance
    ImageReader reader = ImageIO.getImageReadersByMIMEType("image/webp").next();

    // Configure decoding parameters
    WebPReadParam readParam = new WebPReadParam();
    readParam.setBypassFiltering(true);

    // Configure the input on the ImageReader
    reader.setInput(new FileImageInputStream(new File(inputWebpPath)));

    // Decode the image
    BufferedImage image = reader.read(0, readParam);

    ImageIO.write(image, "png", new File(outputPngPath));
    ImageIO.write(image, "jpg", new File(outputJpgPath));
    ImageIO.write(image, "jpeg", new File(outputJpegPath));

}

参考地址：

 https://github.com/nintha/webp-imageio-core

https://segmentfault.com/a/1190000016324137