Java 从字节数组转换和显示图像
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/18079754/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Convert and display image from byte array
提问by bajla
I'm making a program, which gets data about an image in byte array from a server. I'm converting this data into 24bit BMP format (whether its jpeg, png, bmp or 8-24-32bpp). First, I'm saving it to my HD, and then I'm loading it into a JLabel's Icon. Works perfectly, though there are some cases in which I get the following exception:
我正在制作一个程序，它从服务器获取有关字节数组中图像的数据。我正在将此数据转换为 24 位 BMP 格式（无论是 jpeg、png、bmp 还是 8-24-32bpp）。首先，我将它保存到我的 HD，然后我将它加载到 JLabel 的图标中。完美运行，尽管在某些情况下我会遇到以下异常：
java.io.EOFException at
javax.imageio.stream.ImageInputStreamImpl.readFully(ImageInputStreamImpl.java:353) at
com.sun.imageio.plugins.bmp.BMPImageReader.read24Bit(BMPImageReader.java:1188) at
com.sun.imageio.plugins.bmp.BMPImageReader.read(BMPImageReader.java:843) at
javax.imageio.ImageIO.read(ImageIO.java:1448) at
javax.imageio.ImageIO.read(ImageIO.java:1308)
For this line (the second)
对于这条线（第二条）
File imgFile = new File("d:/image.bmp");
BufferedImage image = ImageIO.read(imgFile);
In these cases:
在这些情况下：
- the image does not load into the JLabel, but it can be found on my HD
- the conversion is not proper, because something "slips"
- the picture is like when you use italics in a word document
- 图像未加载到 JLabel 中，但可以在我的 HD 中找到
- 转换不正确，因为有些东西“滑倒”
- 图片就像你在word文档中使用斜体一样
First, i thought maybe the bpp is the problem, then i thought that maybe the pictures are too large, but i have cases it works and cases it doesn't for both suggestions. I'm a little stuck here, and would be glad for ideas.
首先，我认为可能 bpp 是问题所在，然后我认为可能图片太大了，但是我有两种建议都有效的情况和无效的情况。我有点卡在这里，很高兴有想法。
采纳答案by haraldK
- the picture is like .. when You use italics in a word document
- 图片就像..当你在word文档中使用斜体时
Think I finally got what this bullet item meant now.. ;-)
想我终于明白这个项目符号的意思了.. ;-)
Speculative answer, but here goes:
推测性的答案，但这里是：
If the image you write looks "skewed", it's probably due to missing padding for each column as the BMP format specifies (or incorrect width field in the BMP header). I assume then, that the images you get EOF exceptions for, is where the width is not a multiple of 4.
如果您编写的图像看起来“倾斜”，则可能是由于 BMP 格式指定的每列缺少填充（或 BMP 标题中的宽度字段不正确）。我假设，您获得 EOF 例外的图像的宽度不是 4 的倍数。
Try to write the BMPs using ImageIO to see if that helps:
尝试使用 ImageIO 编写 BMP 以查看是否有帮助：
private static BufferedImage createRGBImage(byte[] bytes, int width, int height) {
DataBufferByte buffer = new DataBufferByte(bytes, bytes.length);
ColorModel cm = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), new int[]{8, 8, 8}, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
return new BufferedImage(cm, Raster.createInterleavedRaster(buffer, width, height, width * 3, 3, new int[]{0, 1, 2}, null), false, null);
}
...
...
byte[] bytes = ...; // Your image bytes
OutputStream stream = ...; // Your output
BufferedImage image = createRGBImage(bytes, width, height);
try {
ImageIO.write(image, "BMP", stream);
}
finally {
stream.close();
}
回答by Mohsin Shaikh
You can use this code to convert the output image to a byte Array
您可以使用此代码将输出图像转换为字节数组
Blob b = rs.getBlob(2);
byte barr[] = new byte[(int)b.length()]; //create empty array
barr = b.getBytes(1,(int)b.length());
FileOutputStream fout = new FileOutputStream("D:\sonoo.jpg");
fout.write(barr);
回答by Azad
Call it by class name, liek ClassName.byteArrayToImage(byte):
按类名调用它，例如ClassName.byteArrayToImage(byte)：
public static BufferedImage byteArrayToImage(byte[] bytes){
BufferedImage bufferedImage=null;
try {
InputStream inputStream = new ByteArrayInputStream(bytes);
bufferedImage = ImageIO.read(inputStream);
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
return bufferedImage;
}
