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。

IE

SELECT * 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 dbWHERE    SUBJECT_TYPE ILIKE 'Person' AND    PREDICATE ILIKE 'name' AND    OBJECT_VALUE ILIKE 'John' AND    VERSION ILIKE '0'