java中的字符串拆分不能正常工作，给出错误的结果

Question

String text="2|919505485043|2013-08-08 12:57:50|2013-08-08 12:58:04|2013-08-08 12:58:08|ANSWER";

I want to split string using | .I have the above string in java.When i used

System.out.println(text.split("|").length);

I am getting the result 82.What might be the wrong here.

Answer 1

String#split uses a regular expression as it argument. The pipe character | has special meaning (meaning OR) prevents the String from being split internally at every literal | .

It should be escaped

text.split("\\|").length

otherwise the complete String will be used when determining the length

Answer 2

String.split(String) uses regular expressions, and | has a special meaning within regular expressions.

Options:

• Escape the | manually: text.split("\\\\|")
• Escape the | programmatically: text.split(Pattern.quote("|"))
• Use Guava 's Splitter class instead, to avoid using regular expressions at all

Personally I would go for the latter approach - I think it's actually a design flaw that String.split uses regular expressions at all, and it's unclear in calling code.

If you really want to use String.split , I'd definitely use Pattern.quote to make it clear to anyone reading the code why you're escaping it - just using "\\\\|" isn't very self-documenting, IMO.

Answer 3

你忘记了逃脱角色，

text.split("\\\|");

Answer 4

你应该把\\\\忘了这个。

text.split("\\|")

Answer 5

public class Sstring {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String text="2|919505485043|2013-08-08 12:57:50|2013-08-08 12:58:04 |2013-08-08 12:58:08|ANSWER";
        System.out.println(text.split("\\|").length);
        String str[] = text.split("\\|");

        for(String i:str){
            System.out.println(i);
        }
    }

}

Answer 6

Guava, as usual!

Splitter.on("|").split("your_text")

This returns an Iterable.