Java tif转jpg代码实现

近期项目需要在前端展示 tif 格式的图片，测试发现只有在 ie9以上浏览器及苹果的 Safari 浏览器上能自带支持查看 tif 图片，然而最常用的 Google Chrome浏览器上并不能正常显示。

查了各种资料后自己写了一份实现，欢迎借鉴。

public class TifFile extends FileProcess {

	@Override
	public byte[] tif2JPG(byte[] buffer, InputStream inputStream, String outputFilePath) throws Exception {
		if(buffer==null||buffer.length==0) return null;
		byte[] byt = null;
		String jpgOutFilePath = outputFilePath.replaceAll(".tif", ".jpg");
		File jpgFile = new File(jpgOutFilePath);
		if (jpgFile.exists()) {
			InputStream input = new FileInputStream(jpgFile);
			byt = new byte[input.available()];
			input.read(byt);
			input.close();
			return byt;
		}
		BufferedImage bufferedImage = ImageIO.read(inputStream);  
		
		// 指定写图片的方式为 jpg  
		ImageWriter imgWrier = ImageIO.getImageWritersByFormatName("jpeg").next(); 
		ImageWriteParam imgWriteParams = new javax.imageio.plugins.jpeg.JPEGImageWriteParam(null);  
		// 要使用压缩，必须指定压缩方式为MODE_EXPLICIT  
		imgWriteParams.setCompressionMode(imgWriteParams.MODE_EXPLICIT);
		// 这里指定压缩的程度，参数qality是取值0~1范围内，  
		imgWriteParams.setCompressionQuality(0.5f);  
		imgWriteParams.setProgressiveMode(imgWriteParams.MODE_DISABLED);  
		ColorModel colorModel = ColorModel.getRGBdefault();
		// 指定压缩时使用的色彩模式  
		imgWriteParams.setDestinationType(new javax.imageio.ImageTypeSpecifier(colorModel, colorModel  
		        .createCompatibleSampleModel(16, 16))); 
		ByteArrayOutputStream bos = new ByteArrayOutputStream(buffer.length); 
		
		imgWrier.reset();  
	    // 必须先指定 out值，才能调用write方法, ImageOutputStream可以通过任何 OutputStream构造  
	    imgWrier.setOutput(ImageIO.createImageOutputStream(bos));  
	    // 调用write方法，就可以向输入流写图片  
	    imgWrier.write(null, new IIOImage(bufferedImage, null, null), imgWriteParams); 
	    bos.flush();  
	    bos.close();  
	    inputStream.close();  
	    byte[] result = bos.toByteArray();
	    outputStreamFile(result,jpgFile);
		return result; 
	}
	
	public void outputStreamFile(byte[] buffer,File file) throws Exception {
		  OutputStream os = new FileOutputStream(file);
		  os.write(buffer);
		  os.close();
	  }
}

public class FileProcessUtils {

	public static byte[] convertToJPG(Class clazz, byte[] buffer,InputStream inputStream,String outFilePath,String extension) {  
		byte[] byt = null;
        try {  
        	FileProcess file =  (FileProcess) Class.forName(clazz.getName()).newInstance();  
        	if("tif".equals(extension)) {
        		byt =  file.tif2JPG(buffer, inputStream, outFilePath);
        	}
        	
        } catch (Exception e) {
        	System.out.println(e.getMessage());
        }  
       return byt;
    } 
	
	public static void main(String[] args) throws Exception {
		FileInputStream fis = new FileInputStream("/Users/HJK/Downloads/abcdef.tif");
		byte[] buffer = new byte[fis.available()];
		fis.read(buffer);
		InputStream inputStream = new ByteArrayInputStream(buffer);
		convertToJPG(TifFile.class,buffer, inputStream, "/Users/HJK/Downloads/abcdef.jpg","tif");
	}
}

画个重点，这里需要用到 jai-imageio-core 这个包，如果缺少这个包会导致

BufferedImage bufferedImage = ImageIO.read(inputStream);  

 读取的 BufferedImage 是个空对象，后边会出现参数异常。具体原因因为项目时间紧，暂时没有深入研究，猜测应该是jai-imageio的作者对 ImageIO 做了一些读取 tif 的完善。