Question

如何在运算符上分隔布尔表达式？我将表达式作为以下字符串：

String expression = “((468551X68X304.NAOK == \"2\") and (468551X68X305.NAOK > \"2\") and (468551X68X308.NAOK != \"2000\" or 468551X68X308.NAOK > \"2000\")) “;

我想获取数组中的所有变量，例如：

a[0] = “468551X68X304.NAOK”;
a[1] = “468551X68X305.NAOK”;
a[2] = “468551X68X308.NAOK”;
a[3] = “468551X68X308.NAOK”;

有人可以给我一个解决它的想法吗？

谢谢，

Answer 1

这可以使用正则表达式完成。

以下正则表达式匹配格式化的变量，如布尔表达式中的变量：

\d+X\d+X\d+\.NAOK

每个\d+匹配一个或多个数字。

要使用此正则表达式提取变量，您可以使用java.util.regex.Pattern和java.util.regex.Matcher，如下所示：

String booleanExpression = "((468551X68X304.NAOK == \"2\") and (468551X68X305.NAOK > \"2\") and (468551X68X308.NAOK != \"2000\" or 468551X68X308.NAOK > \"2000\")) ";
String regex = "\\d+X\\d+X\\d+\\.NAOK"; // Note that backslash pairs don't denote two backslashes here. Because we're representing the regex as a string literal, we have to use escape sequences to represent the backslashes in the regex

Matcher m = Pattern.compile(regex).matcher(booleanExpression);
ArrayList<String> variables = new ArrayList<>();
while(m.find()) // Match a NEW variable (one that wasn't matched in previous iterations
    variables.add(m.group()); // Add the matched variable to the ArrayList

如何在运算符（JAVA）上分离布尔表达式？

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