处理管道分隔记录的有效方法？

Question

I've a string which contains data concatenated by pipe (|)

Example: 5|aa@gmail.com|477|en|87477

The string has ~15 fields concatenated by pipe.

It could be possible that some field may have empty data: Example: 5|aa@gmail.com||en|87477

How can I efficiently get all the individual fields in Java 1.6?

Thanks!

Answer 1

Consider using the Split method offered by java

String str = "5|aa@gmail.com|477|en|87477";
String[] data = str.split("\\|");
for(String s : data){
    System.out.println(s);
}

The output i get is

5
aa@gmail.com
477
en
87477

As it's just an array of string you access the data as you want, ie data[1] gives aa@gmail.com

Answer 2

I upvoted the String.split answer because it's simplest. Its two downsides are:

1. uses a regex instead of just finding a single char; a bit of extra overhead for the generalization
2. has to re-compile the regex pattern each time

To get a slight increase, if you need it, you can pre-compile the pattern and then use that to split:

import java.util.regex.Pattern;
private static final Pattern BAR_REGEX = Pattern.compile( Pattern.quote("|") );

and then in your method:

String[] splits = BAR_REGEX.split( inputString );

Answer 3

You may also want to consider the StringUtils class from Apache Commons Lang . Very fast and does indeed handle 'missing' tokens.

Answer 4

Alan's solution will work most times except if you have empty token(s) in the end. For example,

String str = "5|aa@gmail.com|477|en||||87477||x|||";

You could solve this by

• Using another variant of split with a negative value for limit, (see javadoc )

String str = "5|aa@gmail.com|477|en||||87477||x|||";

str.split("\\\\|", -1);

• or use commons.StringUtils.splitPreserveAllTokens(str, delim)

Answer 5

考虑使用StringTokenizer类。