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How can I print * in the place of input character which is entered from keyboard?

Example:

If I type in the console: mouli, then it should replace m with * and then o with * and so on.

aioobe
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user1472618
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  • Replacing each character with `*`? Replacing the entire string with `*`? Replacing only some characters (m and o, for example) with `*`? Please clarify your question. – Platinum Azure Jun 21 '12 at 15:42
  • I guess he wants to override the `stdin` echoing and replace some character – Jack Jun 21 '12 at 15:43
  • Possible duplicate of [word (password) displays in asterisks - Console application](http://stackoverflow.com/questions/10667929/word-password-displays-in-asterisks-console-application). The answer there contains a solution which includes (command line) masking... – ChristopheD Jun 21 '12 at 15:44
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    Why is this tagged [tag:oracle10g]? – Evan Mulawski Jun 21 '12 at 15:44

2 Answers2

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There's no way of solving this using the standard API. If this is indeed an explicit requirement, you'll have to use some system specific library that interacts with the underlying terminal.

If the intention is to let the user enter a password however, I suggest you use Console.readPassword.

aioobe
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  • This answer (http://stackoverflow.com/a/10668040/81179) is mentioning to a way to make this work without going system specific: http://java.sun.com/developer/technicalArticles/Security/pwordmask/ (also see duplicate linked above) – ChristopheD Jun 21 '12 at 15:57
  • Right. By fiddling with thread priorities and printing `"\010*"` repeatedly... Nothing I would recommend someone to do to be honest. – aioobe Jun 21 '12 at 16:05
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The console is not a "part" of Java. It's just one of many means of inputting information to your program. I think your question is more like:

"I'm reading a string in from the Keyboard, and I want to replace every character with an asterisk".

But I'm not sure if that's actually what you want.

Alternatively, if you're trying to make a "password" entry field in the console, where typed characters appear as asterisks, you may want to look into the Console class, seen here. However, I would lean towards the assumption that your purpose would be better suited by an actual GUI. The readPassword method only stops the letters from appearing on the screen, but doesn't replace them.

Nick
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  • Why the -1? It's approaching the question differently but this is a relevant answer. (+1 to cancel) – Platinum Azure Jun 21 '12 at 15:47
  • I put the -1, and then started typing my reasoning that I didn't feel it was a very good answer. Then I decided that I'd rather just *not* -1 it and leave it alone. But the answerer deleted the answer so I couldn't undo it. Then the answerer undeleted the answer. So I removed my -1 just now. – Erick Robertson Jun 21 '12 at 15:49
  • @ErickRobertson haha, I apologize. I for a moment thought I wrote something utterly incorrect, then realized it was only partially incorrect and opted for an edit instead. – Nick Jun 21 '12 at 15:50