java正则表达式分割模式

Question

我想分割以下字符串:

String line ="DOB,1234567890,11,07/05/12,\"first,last\",100,\"is,a,good,boy\"";

转换为以下标记:

DOB
1234567890
11
07/05/12
first,last
100
is,a,good,boy

我尝试使用以下正则表达式:

import java.util.*;
import java.lang.*;
import java.util.regex.*;
import org.apache.commons.lang.StringUtils;

class SplitString{

    public static final String quotes = "\".[[((a-z)|(A-Z))]+( ((a-z)|(A-Z)).,)*.((a-z)|(A-Z))].\"" ;
    public static final String ISSUE_UPLOAD_FILE_PATTERN = "((a-z)|(A-Z))+ [(((a-z)|(A-Z)).,)* + ("+quotes+".,) ].((a-z)|(A-Z)) + ("+quotes+")";

    public static void main(String[] args){

        String line ="DOB,1234567890,11,07/05/12,\"first,last\",100,\"is,a,good,boy\"";
        String delimiter = ",";

    Pattern p = Pattern.compile(ISSUE_UPLOAD_FILE_PATTERN);

    Pattern pattern = Pattern.compile(ISSUE_UPLOAD_FILE_PATTERN);
    String[] output = pattern.split(line);

    System.out.println(" pattern: "+pattern);

    for(String a:output){
        System.out.println(" output: "+a);
    }

    }             
}

我在正则表达式中遗漏了什么吗？

Answer 1

这是代码的更新版本，可为您提供预期的输出:

public static final String ISSUE_UPLOAD_FILE_PATTERN = "(?<=(^|,))(([^\",]+)|\"([^\"]*)\")(?=($|,))";
public static void main(String[] args) {
    String line = "DOB,1234567890,11,07/05/12,\"first,last\",100,\"is,a,good,boy\"";
    Matcher matcher = Pattern.compile(ISSUE_UPLOAD_FILE_PATTERN).matcher(line);
    while (matcher.find()) {
        if (matcher.group(3) != null) {
            System.out.println(matcher.group(3));
        } else {
            System.out.println(matcher.group(4));
        }
    }
}

正则表达式的工作原理如下: (?<=(^|,)) :检查匹配之前的字符是否是字符串的开头或 ,
(([^\",]+)|\"([^\"]*)\") :匹配 "<any number of (not")>" 或 any number of (not" or ,)
(?=($|,)) :检查匹配后的字符是否为字符串结尾或 ,
结果将是第 3 组或第 4 组，具体取决于匹配的部分。