Question about java.util.regex.Pattern

[frosted74]

Hi,

I am trying to use a Pattern to match certain strings in error
messages in our application. We are delimiting them using the
following notation, {0}, {1}, etc. I am trying to use String's
replaceFirst (even replaceAll) method to replace the instances of
these tokens with appropriate Strings. I am using the following code:

String match = "\\{0\\}";
String message = "{0} should be 5 characters in length.";
String replacement = "Zip Code";
message.replaceAll( match, replacement );

message is unaffected by this method call.

This pattern /\{0\}/ works on online RegEx testers, but I feel I am
missing an important step porting it to java's Pattern class. I have
tried sticking /'s into the string, ending it with "g", etc. Nothing
seems to work. anyone have any insight into how I can do this or what
I am doing incorrectly?

TIA.

 

[Jussi Piitulainen]

String message = "{0} should be 5 characters in length.";
String replacement = "Zip Code";
message.replaceAll( match, replacement );

message is unaffected by this method call.

Strings are immutable. The method returns a new String.
message = message.replaceAll( match, replacement );

 

[frosted74]

Strings are immutable. The method returns a new String.
message = message.replaceAll( match, replacement );

*Slaps self in forehead*. Thanks Jussi!!

 

[Roedy Green]

I am trying to use a Pattern to match certain strings in error
messages in our application. We are delimiting them using the
following notation, {0}, {1}, etc. I am trying to use String's
replaceFirst (even replaceAll) method to replace the instances of
these tokens with appropriate Strings. I am using the following code:

you don't want a regex replace. You are just looking for an ordinary
string. "{0}"

so use String.replace to replace all, not String.replaceAll.

 

[Roedy Green]

so use String.replace to replace all, not String.replaceAll.

see http://mindprod.com/jgloss/string.html
for basic hints on using the class, including gotchas.