ImageIO.read返回NULL，没有错误 [英] ImageIO.read returns NULL, with no errors

问题描述

以下代码似乎不起作用，即使文件看起来很好。

The following code seems not to work, even though the file appears to be found just fine.

    images = new BufferedImage[32];
    FileInputStream fis = null;
    for (int i = 0; i < 32; i++) {
        File file = new File("tiles\\"+i+".bmp");
        if (!file.exists()){
            System.out.println("File  "+i+" failed");
        }
        try { 
            fis = new FileInputStream(file); 
        } catch (FileNotFoundException e) { 
            System.err.println(e + "" + i); 
        }
        try { 
            images[i] = ImageIO.read(fis); 
        } catch (IOException e) { 
            System.err.println(e + "" + i); 
        }
        if (images[i] == null) {
            System.out.println("Image "+i+" failed");
        }
    }

提前感谢您的帮助。

编辑：结果是我尝试使用Graphics.drawImage（images [0]）;,它给我一个空指针异常。此代码在此处完成。

The result is me attempting to Graphics.drawImage(images[0]);, and it giving me a null pointer exception. This code here completes fine.

编辑：已更改按照建议移动了if（！file.exists（）），并将文件包装在输入流中。

Changed moved the if(!file.exists()) as suggested, and wrapped the file in an input stream.

推荐答案

ImageIO.read（file）; 如果没有注册 ImageReader 将返回null找不到。请检查您是否注册了 ImageReader 。

ImageIO.read(file); will return null if no registered ImageReader is not found. Please check whether you have registered any ImageReader or not.

我认为此代码段可以帮助您

I think this code snippet could help you

File file = new File("bear.jpg"); // I have bear.jpg in my working directory  
    FileInputStream fis = new FileInputStream(file);  
    BufferedImage image = ImageIO.read(fis); //reading the image file  

您只需将文件包装成 FileInputStream 然后将其传递给读取（）

You just need to wrap the file into an FileInputStream and then pass it to read()

这篇关于ImageIO.read返回NULL，没有错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！