将自定义属性或元数据添加到文件 java [英] add custom attribute or metadata to file java

问题描述

我的文件需要一个名为使用的加密"的额外属性.但这给出了IllegalArgumentExeption".我知道为什么它会出现该错误，使用的加密"不被称为属性，但有没有办法强制它?或者向文件添加自定义元数据?

I have files that need an extra attribute called "encryption used". But this gives "IllegalArgumentExeption". I know why it gives that error, "encryption used" isn't known as an attribute, but is there a way I can force it to be? Or add custom metadata to the file?

 Path path = new File("/propertyfiles/encdec.properties").toPath();

    try{
        Files.setAttribute(path, "encryption used", "testtesttest");
    }catch(IOException e){
        System.out.println(e.getMessage());
    }
    try{
        System.out.println(Files.getAttribute(path, "encryption used"));
    }catch(IOException e){
        System.out.println(e.getMessage());
    }

推荐答案

如果你的文件系统支持用户定义(又名扩展)属性，那么设置一个的方法是这样的:

If your file system supports user-defined (aka extended) attributes, then the way to set one would be like this:

Files.setAttribute(path, "user:encryption used", "testtesttest");

作为 javadoc for setAttribute 解释，第二参数采用可选的 view-name 和属性名称的形式.在这种情况下，您需要使用 UserDefinedFileAttributeView 其视图名称为user".

As the javadoc for setAttribute explains, the 2nd argument takes the form of an optional view-name and an attribute name. In this case, you need to use the UserDefinedFileAttributeView whose view-name is "user".

注意，不同的文件系统类型支持不同的属性视图，你的文件系统可能不支持这个.

Note that different file system types support different attribute views, and your file system may not support this one.

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