How do I replace all "[", "]" and double quotes in Java

Question

I'm am having difficulty using the replaceAll method to replace square brackets and double quotes. Any ideas?

Edit:

So far I've tried:

replace("\[", "some_thing") // returns illegal escape character
replace("[[", "some_thing") // returns Unclosed character class
replace("^[", "some_thing") // returns Unclosed character class

tried replaceAll("^[", "something"), replaceAll("\[", "..."), replace("\[", " "). — chutsu, Nov 28 '11 at 22:15
You'll want to show us a small test program that includes a test String, your code, and the results you obtained. — Hovercraft Full Of Eels, Nov 28 '11 at 22:16
Did `URLEncoder` not work, or something? http://stackoverflow.com/questions/8301699/httpclient-httpget-doesnt-accept-square-brackets — Rob Hruska, Nov 28 '11 at 22:20
@FailedDev - I'm going to guess they're being replaced with `%5B` and `%5D`, respectively. — Rob Hruska, Nov 28 '11 at 22:26

Mark Peters · Accepted Answer · 2011-11-28T22:21:52.483

Don't use replaceAll, use replace. The former uses regular expressions, and [] are special characters within a regex.

String replaced = input.replace("]", ""); //etc

The double quote is special in Java so you need to escape it with a single backslash ("\"").

If you want to use a regex you need to escape those characters and put them in a character class. A character class is surrounded by [] and escaping a character is done by preceding it with a backslash \. However, because a backslash is also special in Java, it also needs to be escaped, and so to give the regex engine a backslash you have to use two backslashes (\\[).

In the end it should look like this (if you were to use regex):

String replaced = input.replaceAll("[\\[\\]\"]", "");

ziesemer · Answer 2 · 2011-11-28T22:24:17.830

The replaceAll method is operating against Regular Expressions. You're probably just wanting to use the "replace" method, which despite its name, does replace all occurrences.

Looking at your edit, you probably want:

someString
.replace("[", "replacement")
.replace("]", "replacement")
.replace("\"", "replacement")

or, use an appropriate regular expression, the approach I'd actually recommend if you're willing to learn regular expressions (see Mark Peter's answer for a working example).

score 1 · Answer 3 · answered Nov 28 '11 at 22:16

replaceAll() takes a regex so you have to escape special characters. If you don't want all the fancy regex, use replace().

String s = "[h\"i]";
System.out.println( s.replace("[","").replace("]","").replace("\"","") );

With double quotes, you have to escape them like so: "\""

score 0 · Answer 4 · answered Nov 28 '11 at 22:18

0

In java:

String resultString = subjectString.replaceAll("[\\[\\]\"]", "");

this will replace []" with nothing.

answered Nov 28 '11 at 22:18

FailedDev

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However, it will *only* replace exactly `[]"` in that order. It wouldn't replace individual occurrences of each of those characters. – Mark Peters Nov 28 '11 at 22:20
@MarkPeters Oups.. It's getting late I guess :) – FailedDev Nov 28 '11 at 22:23

score 0 · Answer 5 · answered Nov 29 '11 at 05:15

Alternatively, if you wished to replace ", [ and ] with different characters (instead of replacing all with empty String) you could use the replaceEachRepeatedly() method in the StringUtils class from Commons Lang.

For example,

String input = "abc\"de[fg]hi\"";
String replaced = StringUtils.replaceEachRepeatedly(input, 
    new String[]{"[","]","\""}, 
    new String[]{"<open_bracket>","<close_bracket>","<double_quote>"});
System.out.println(replaced);

Prints the following:

abc<double_quote>de<open_bracket>fg<close_bracket>hi<double_quote>

How do I replace all "[", "]" and double quotes in Java

5 Answers5