java - 从 java InputStream 打开图像文件

Question

我正在尝试使用运行程序的计算机的默认图像查看器打开打包在 .jar 文件中的图像文件。

我找到了很多关于如何使用 InputStream 访问打包在 jar 中的文件的答案，但是如何使用 InputStream 打开这些文件？

InputStream imageStream = Test.class.getClass().getResourceAsStream("/test/DSC_6283.jpg");

我可以将其转换为 Image , ImageIcon或 BufferedImage但是如何在默认图像查看器中进一步打开图像？

我的类(class)名称是“Test”，我尝试访问的图像是 C:\Users\Pranav\Documents\NetBeansProjects\Test\src\test\DSC_6283.jpg
任何帮助，将不胜感激。

Answer 1

纯Java:

public static void main(String... args) throws IOException {
    InputStream imageStream = Test.class.getClass().getResourceAsStream("/test/DSC_6283.jpg");
    Path path = Files.createTempFile("DSC_6283", ".jpg");
    try (FileOutputStream out = new FileOutputStream(path.toFile())) {
        byte[] buffer = new byte[1024]; 
        int len; 
        while ((len = imageStream.read(buffer)) != -1) { 
            out.write(buffer, 0, len); 
        }
    } catch (Exception e) {
        // TODO: handle exception
    }
    Desktop.getDesktop().open(path.toFile());
}

编辑:

        byte[] buffer = new byte[1024]; //allocate an array of bytes to use as a buffer. 1024 bytes in this case
        int len; //a variable to record the number of bytes actually read from the stream each loop
        while ((len = imageStream.read(buffer)) != -1) { //InputStream.read(byte[]) reads bytes from the stream and places them into the buffer. It returns the number of bytes placed into the buffer, or -1 if there is nothing more to read. We store that result in len, and evaluate if we should stop looping (ie if the return is -1)
            out.write(buffer, 0, len); //write to the output file, from the buffer, starting at position 0, through the number of bytes read

请注意，这是样板文件。我从 Easy way to write contents of a Java InputStream to an OutputStream 那里偷了这个版本