如何使用Java分割带有特殊字符的字符串

Question

What is the way, how to split String with special character using Java?

I have very simple captcha like this:

5 + 10

String captcha = "5 + 10";
String[] captchaSplit = captcha.split("+");

And I get error:

Exception in thread "main" java.util.regex.PatternSyntaxException: Dangling meta character '+' near index 0

How to fix it?

Thank you.

Answer 1

+ is a reserved character in regular expression and split takes regExp as a parameter. You can escape it by \\\\+ which will now match + .

Answer 2

Type it in square brackets

String captcha = "5 + 10";
String[] captchaSplit = captcha.split("[+]");

Answer 3

If you need to split String with multiple special symbols/characters, it's more convenient to use Guava library that contains Splitter class:

    @Test
    public void testSplitter() {
        String str = "1***2***3";
        List<String> list = Lists.newArrayList(Splitter.on("***").split(str));
        Assert.assertThat(list.size(), is(3));
    }