从字节数组获取bufferedImage [英] getting a bufferedImage from a bytearray

问题描述

我正在尝试从字节数组中获取 bufferedImage ，但是却收到一条错误消息，指出 bufferedimage为空.实际上，我尝试了几种方法，所有操作都以相同的方式结束.这是我的代码:

1)

  byte [] arr = Base64.decode(base64String);BufferedImage bImageFromConvert = ImageIO.read(new ByteArrayInputStream(arr)); 

2)

  InputStream in = new ByteArrayInputStream(arr);BufferedImage bImageFromConvert = ImageIO.read(in); 

我非常确定我的字节数组包含数据，并且我认为 ImageIO.read()是我的代码出问题的地方.

解决方案

错误已在注释中发布的 BufferedImage 到 Base64 编码方法中出现./p>

您永远不会将 BufferedImage 写入 ByteArrayOutputStream .因此，Base64字符串为空，读取空字符串将生成 null BufferedImage .

您应该使用以下代码对图像进行编码:

  BufferedImage originalImage = ImageIO.read(new File("G:\\ a.jpg"));ByteArrayOutputStream baos = new ByteArrayOutputStream();ImageIO.write(originalImage，"jpg"，baos);字符串base64String = Base64.encode(baos.toByteArray()); 

要解码图像，请使用以下代码:

  byte [] arr = Base64.decode(base64String);BufferedImage bImageFromConvert = ImageIO.read(new ByteArrayInputStream(arr));System.out.println(bImageFromConvert.getWidth()); 

I am trying to get back a bufferedImage from array of bytes, but I am getting an error saying bufferedimage is null. I actually tried several ways, everything ended up in the same way. Here goes my code:

1)

 byte[] arr = Base64.decode(base64String);
 BufferedImage bImageFromConvert =ImageIO.read(new  ByteArrayInputStream(arr));

2)

 InputStream in = new ByteArrayInputStream(arr);
 BufferedImage bImageFromConvert = ImageIO.read(in);

I am pretty sure my byte array contains data and I think ImageIO.read() is where my code goes wrong.

解决方案

The error is in your BufferedImage to Base64 encode method as you have posted in the comments.

You are never writing the BufferedImage to the ByteArrayOutputStream. Therefore the Base64 string is empty, and reading the empty string produces a null BufferedImage.

You should use this code to encode your image:

 BufferedImage originalImage = ImageIO.read(new File("G:\\a.jpg"));
 ByteArrayOutputStream baos = new ByteArrayOutputStream();
 ImageIO.write( originalImage, "jpg", baos );
 String base64String=Base64.encode(baos.toByteArray());

To decode the image use this code:

 byte[] arr = Base64.decode(base64String);
 BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
 System.out.println(bImageFromConvert.getWidth());

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