Replacing illegal character in fileName

问题

In Java, I've a File-Name-String. There I want to replace all illegal Characters with '_', but not a-z, 0-9, -,. and _

I tried following code: But this did not worked!

myString = myString.replaceAll("[\\W][^\\.][^-][^_]", "_");

回答1:

You need to replace everything but [a-zA-Z0-9.-]. The ^ within the brackets stands for "NOT".

myString = myString.replaceAll("[^a-zA-Z0-9\\.\\-]", "_");

回答2:

If you are looking for options on windows platform then you can try below solution to make use of all valid characters other than "\/:*?"<>|" in file name.

fileName = fileName.replaceAll("[\\\\/:*?\"<>|]", "_");

回答3:

Keep it simple.

myString = myString.replaceAll("[^a-zA-Z0-9.-]", "_");

http://ideone.com/TINsr4

回答4:

Even simpler

myString = myString.replaceAll("[^\\w.-]", "_");

Predefined Character Classes:

• \w A word character: [a-zA-Z_0-9]

回答5:

I know there have been some answers here already, but I would like to point out that I had to alter the given suggestions slightly.

filename.matches("^.*[^a-zA-Z0-9._-].*$")

This is what I had to use for .matches in Java to get the desired results. I am not sure if this is 100% correct, but this is how it worked for me, it would return true if it encountered any character other than a-z A-Z 0-9 (.) (_) and (-).

I would like to know if there are any flaws with my logic here.

In previous answers I've seen some discussion of what should or should not be escaped. For this example, I've gotten away without escaping anything, but you should escape the (-) minus character to be safe as it will "break" your expression unless it is at the end of the list. The (.) dot character doesn't have to be escaped within the ([]) Square Braces it would seem, but it will not hurt you if you do escape it.

Please see Java Patterns for more details.

回答6:

If you want to use more than like [A-Za-z0-9], then check MS Naming Conventions, and dont forget to filter out "...Characters whose integer representations are in the range from 1 through 31,...".

回答7:

for NodeJS (v10), the function replaceAll() is undefined!

The solution is:

let newName = myString.replace(/[^a-zA-Z0-9.-]/gi, "_");

来源：https://stackoverflow.com/questions/15075890/replacing-illegal-character-in-filename