Java：拆分分号分隔的字符串但忽略引号中的转义+分号

Question

我想拆分我的查询，但没有得到完全符合我要求的答案。

我的字符串如下所示：

选择 1;选择 \\\\2; select 3\\\\;copy customer from 's3://mybucket/mydata' 凭证 'aws_access_key_id=access_key\\\\;aws_secret_access_key=secret_key\\\\;master_symmetric_key=master_key'

所需的输出：

选择 1

选择 \\\\2

选择 3\\\\

从 's3://mybucket/mydata' 凭证复制客户 'aws_access_key_id=access_key\\\\;aws_secret_access_key=secret_key\\\\;master_symmetric_key=master_key'

我找到了关于逃生者的解决方案。 但是不符合我的要求。

(?<!\\\\);

在 Java String.split() 方法中处理带有转义字符的分隔符

如何忽略引号中的转义+分号？

帮我。

Answer 1

我认为这是一个解决方案：

String line = "select 1;select \\2; select 3\\;copy customer from 's3://mybucket/mydata' credentials 'aws_access_key_id=access_key\\;aws_secret_access_key=secret_key\\;master_symmetric_key=master_key'";
line = line.replace("\\","\\\\");//To avoid missing \
String[] tokens = line.split(";(?=([^']*'[^']*')*[^']*$)");//To split on semmicolons, but not those inside quotes
for(String t : tokens) {
    System.out.println("> "+t);
}

你可以在这里测试它http://rextester.com/MLTA75734

Answer 2

您可以使用外部 .jar 文件，例如 commons-lang-2.6.jar

String str = "select 1;select \\2; select 3\\;copy customer from 's3://mybucket/mydata' credentials 'aws_access_key_id=access_key\\;"
            + "aws_secret_access_key=secret_key\\;"
            + "master_symmetric_key=master_key'";
    str = StringEscapeUtils.escapeJavaScript(str); // method from external jar
    String st[] = str.split(";");
    for(int i=0;i<st.length;i++)
    System.out.println(st[i]);

希望能帮到你...

Answer 3

我尝试了另一种解决方案，这次没有正则表达式。 我用我能想到的尽可能多的奇怪字符串检查了这个，它按我的预期工作（希望这次它也能按你的预期工作），请检查一下。

       String s ="select 1;r;select \\2; select 3\\;copy customer from 's3://mybucket/mydata' credentials 'aws_access_key_id=<access-key-id>\\;aws_secret_access_key=<secret-access-key>\\;master_symmetric_ke‌​y=<master-key>'";
               //"select 1;r;select \\2; select 3\\;copy customer from 'r;s3://mybucket/mydata;r' credentials 'a_key;b_key;c_key\\;r' 'aws_access_key_id=access_key\\;aws_secret_access_key=secret_key\\;master_symmetric_key=master_key'";
       s = s.replace("\\","\\\\");
       List<String> tokens = new ArrayList<String>();               
       int i = 0;    
       int j = 0;
       String backup = s;
       while (i < s.length()){
        char c  = s.charAt(i);      
          if(c==';'){
            String previous = s.substring(0,i);
            int quotesBefore = StringUtils.countMatches(backup.substring(0,j), "'");
            if(i<2 || quotesBefore==0 || (i>1 && (quotesBefore & 1) == 0 || ((quotesBefore & 1) != 0) && !(s.charAt(i-1)=='\\' && s.charAt(i-2)=='\\'))){//Even quotes before OR (odd quotes AND not \\ right before)                 
                tokens.add(previous);
                if(i>0)s=s.substring(i+1);
                i=0;
            }
          }
          i++;j++;
        }
        tokens.add(s);
        for(String t : tokens) {
            System.out.println("> "+t);
        }

基本步骤：

1. 迭代字符串字符

2. 对于每个检查它是否是分号

3. 如果这是真的，请获取之前的字符，计算引号并将这些字符添加到列表中，仅当它是奇数或偶数但分号没有用“\\\\”转义时

Answer 4

我使用了以下解决方案，用于带引号（' 和“）和转义（\\）字符的通用 sting 拆分器。

public static List<String> split(String str, final char splitChar) {
    List<String> queries = new ArrayList<>();
    int length = str.length();
    int start = 0, current = 0;
    char ch, quoteChar;
    
    while (current < length) {
        ch=str.charAt(current);
        // Handle escape char by skipping next char
        if(ch == '\\') {
            current++;
        }else if(ch == '\'' || ch=='"'){ // Handle quoted values
            quoteChar = ch;
            current++;
            while(current < length) {
                ch = str.charAt(current);
                // Handle escape char by skipping next char
                if (ch == '\\') {
                    current++;
                } else if (ch == quoteChar) {
                    break;
                }
                current++;
            }
        }else if(ch == splitChar) { // Split sting
            queries.add(str.substring(start, current + 1));
            start = current + 1;
        }
        current++;
    }
    // Add last value
    if (start < current) {
        queries.add(str.substring(start));
    }
    return queries;
}

public static void main(String[] args) {

    String str = "select 1;select \\\\2; select 3\\\\;copy customer from 's3://mybucket/mydata' credentials 'aws_access_key_id=access_key\\\\;aws_secret_access_key=secret_key\\\\;master_symmetric_key=master_key'";
    List<String> queries = split(str, ';');
    System.out.println("Size: "+queries.size());
    for (String query : queries) {
        System.out.println(query);
    }
}

得到结果

Size: 4
select 1;
select \\2;
 select 3\\;
copy customer from 's3://mybucket/mydata' credentials 'aws_access_key_id=access_key\\;aws_secret_access_key=secret_key\\;master_symmetric_key=master_key'