Java RegEx 没有替换所有预期的模式

Question

我想要实现的只是用 ILIKE 代替比较等于，而不是赋值语句。IESELECT * FROM db WHERE SUBJECT_TYPE = 'Person';应该替换为SELECT * FROM db WHERE SUBJECT_TYPE ILIKE 'Person';然而SET session ABC.VAR = 5;应该保持不变。为此，我正在尝试使用前瞻性，以便在等于 (=)之前没有SET。爪哇String str = "SELECT * FROM db WHERE SUBJECT_TYPE = 'Person' AND PREDICATE = 'name' AND OBJECT_VALUE = 'John' AND VERSION = '0' "final Pattern EQUALS_ILIKE_PATTERN = Pattern.compile("(?i)((^((?!SET)[^=])+?)\\s*)=");final Matcher matcher = EQUALS_ILIKE_PATTERN .matcher(str);while (matcher.find()){    final String fromString = matcher.group(0);    str = matcher.replaceAll("$1 ILIKE");}System.out.println(str);实际结果：SELECT * FROM DB WHERE SUBJECT_TYPE ILIKE 'Person' AND PREDICATE = 'name' AND OBJECT_VALUE = 'John' AND VERSION = '0'预期结果：SELECT * FROM DB WHERE SUBJECT_TYPE ILIKE 'Person' AND PREDICATE ILIKE 'name' AND OBJECT_VALUE ILIKE 'John' AND VERSION ILIKE '0'这里的实际结果不会替换所有必要的等号 (=)。

Answer 1

我们可以通过单行调用来做到这一点String#replaceAll：

 String str = "SELECT * FROM db WHERE SUBJECT_TYPE = 'Person' AND PREDICATE = 'name' AND OBJECT_VALUE = 'John' AND VERSION = '0' ";

str = str.replaceAll("(WHERE|AND)\\s+(\\S+)\\s+=(?=\\s*'[^'+]+')", "$1 $2 ILIKE");

System.out.println(str);

此输出（格式化为可读性）：

SELECT *

FROM db

WHERE

    SUBJECT_TYPE ILIKE 'Person' AND

    PREDICATE ILIKE 'name' AND

    OBJECT_VALUE ILIKE 'John' AND

    VERSION ILIKE '0'