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Closed 10 years ago.
Possible Duplicate:
java String.replaceAll without regex
I have a string and I need to replace some parts of it.
The replacement text contains regex wild chars though. Example:
String target = "Something * to do in ('AAA', 'BBB')";
String replacement = "Hello";
String originalText = "ABCDEFHGIJKLMN" + target + "ABCDEFHGIJKLMN";
System.out.println(originalText.replaceAll(target, replacement));
I get:
ABCDEFHGIJKLMNSomething * to do in ('AAA', 'BBB')ABCDEFHGIJKLMN
Why doesn't the replacement occur?
Because *, ( and ) are all meta-characters in regular expressions. Hence all of them need to be escaped. It looks like Java has a convenient method for this:
java.util.regex.Pattern.quote(target)
However, the better option might be, to just not use the regex-using replaceAll function but simply replace. Then you do not need to escape anything.
String.replaceAll() takes a regular expression and so it's trying to expand these metacharacters.
One approach is to escape these chars (e.g. \*).
Another would be to do the replacement yourself by using String.indexOf() and finding the start of the contained string. indexOf() doesn't take a regexp but rather a normal string.
Related
This question already has answers here:
My regex is matching too much. How do I make it stop? [duplicate]
(5 answers)
Closed 4 years ago.
I want to replace &sp; in the string below with Z.
Input text : ABCD&sp;EF&p;GHIJ&bsp;KL
Output text : ABCDZEFZGHIZKL
Can anyone tell me how to replace the every instance of &\D+; using java regular expression?
I am using /(&\D+;)?/ but it doesn't work.
Use String#replaceAll.
You also should use the ? modificator to +:
String str = "ABCD&sp;EF&p;GHIJ&bsp;KL";
String regex = "&\\D+?;";
System.out.println (str.replaceAll(regex,"Z"));
This should work
Match the initial &, then all characters that are not the tailing ;, then that tailing ; like so: &[^;]+; If not matching numbers (as suggested by your example with \D) is a requirement, add the numbers to the negated character set: [^;0-9] To make it replace all occurrences, add the global flag g. The site regexr.com is a handy tool to create regexes.
Edit: Sorry, I initially read your question wrong.
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Splitting a Java String by the pipe symbol using split("|")
(7 answers)
Closed 7 years ago.
I have a file with content
1|yes|
2|yes|
3|yes|
4|yes|
5|yes|
6|yes|
7|yes|
8|yes|
9|yes|
10|yes|
11|yes|
12|yes|
13|yes|
14|yes|
15|yes|
I use java's String[] tokens = split("|"); to split each line, but it returns (for example splitting "10|yes|") [1,0,|,y,e,s,|]. It seems instead of splitting by "|", it splits every character. Anyone has any idea on it? Thanks!
split accepts a regular expression. | has a specific meaning in regular expressions, it expresses an alternation. To actually split on |, you have to escape it in the regex with a backslash. Since you specify the regex using a string literal, and backslashes are special in string literals, you have to escape that with another backslash:
String[] tokens = str.split("\\|");
In the general case, if you want to use the contents of a string literally, you can use Pattern.quote to automatically escape any special characters. You don't really need it here, but it's useful for end-user-entered values:
String[] tokens = str.split(Pattern.quote(stringToSplitOnLiterally));
This question already has answers here:
Removing repeated characters in String
(4 answers)
Closed 8 years ago.
Lets say I have a string:
tttteeeeeeessssssttttttt
Using the power of regex, how can that string be turned into:
test
At first look it seems easy to do, but the current code (not regex) I have for it is not behaving well and im pretty sure regex is the way to go.
You can use:
str = str.replaceAll("([A-Za-z])\\1+", "$1");
RegEx Demo
Use string.replaceAll function.
strng.replaceAll("(.)\\1+", "$1");
The above regex captures the first character in the sequence of same characters and matches all the following one or more characters (which must be same as the one inside the capturing group) . Replacing those characters with the character inside group index 1 will give you the desired output.
Example:
System.out.println("tttteeeeeeessssssttttttt".replaceAll("(.)\\1+","$1" ));
Output:
test
(.)(?=\1)
Try this.Replace by empty string.See demo.
https://regex101.com/r/tX2bH4/41
str = str.replaceAll("(.)(?=\\1)", "");
This question already has answers here:
illegal string body character after dollar sign
(5 answers)
Closed 8 years ago.
I am using spock to test a java app.It seems "$" is a special character in groovy.any java string that is separated by "$" can't be separated in groovy properly.Any workaround for this problem?
update
The "split" happened in java code that I can't edit. It turns out that java code has a problem same as:Why can't I split a string with the dollar sign?
I don't think $ is a special character in Groovy strings. Edit: Yes, it is, if you use GStrings! But the rest may still be useful: But it's a special character in the string you give to String#split, because that string is interpreted as a regular expression, and in a regular expression, $ is "end of input" (or end of line, depending on flags).
If you're using String#split, to make it split on a literal $, you have to escape it with a backslash. To make the regex engine see a backslash, you have to escape the backslash in a string literal with another backslash.
Example:
'testing$one$two$three'.split('\\$').each {
println it
}
Output:
testing
one
two
three
Better yet, as suggested by Dónal, use tokenize:
Example:
'testing$one$two$three'.tokenize('$').each {
println it
}
(Same output)
This question already has answers here:
Replace a question mark (?) with (\\?)
(2 answers)
replace String with another in java
(7 answers)
Closed 9 years ago.
is it possible to replace all the questionmarks ("?") with "\?" ?
Lets say I have a String, and I want to delete some parts of that String, one part with an URL in it. Like this:
String longstring = "..."; //This is the long String
String replacestring = "http://test.com/awesomeness.asp?page=27";
longstring.replaceAll(replacestring, "");
But! As I understand it you can't use the replaceAll() method with a String that contains one single questionmark, you have to make them like this "\?" first.
So the question is; Is there some way to replace questionmarks with "\?" in a String? And no, I'm able to just change the String.
Thanks in advance, hope someone understands me! (Sorry for bad English...)
Don't use replaceAll(), use replace()!
It is a common misconception that replaceAll() replaces all occurrences and replace() just replaces one or something. This is totally incorrect.
replaceAll() is poorly named - it actually replaces a regex.
replace() replaces simple Strings, which is what you want.
Both methods replace all occurrences of the target.
Just do this:
longstring = longstring.replace(replacestring, "");
And it will all work.
Escape the \ too, using \\\\?.
String longstring = "..."; //This is the long String
String replacestring = "http://test.com/awesomeness.asp?page=27";
longstring=longstring.replaceAll(replacestring, "\\\\?");
But as other answer have mentioned, replaceAll is a bit overkill, just a replace should work.
replaceAll takes a regular expression, and ? has a special meaning in the regex world.
You should use replace in this case, since you don't need a regex.
String longstring = "..."; //This is the long String
String replacestring = "http://test.com/awesomeness.asp?page=27";
longstring = longstring.replace(replacestring, "");
Oh, and strings are immutable!! longstring = longstring.replace(..), notice the assignment.
Use String.replace() instead of String.replaceAll():
longstring = longstring.replace("?", "\\?");
String.replaceAll() uses Regular Expression, while String.replace() uses plain text.