如何匹配3个参数，包括通配符匹配？

Question

我想定义一个由值组成的黑名单过滤器。让他们按照这个顺序。a, b, c

为了快速查找，我想将它们连接成一个，这样我就可以快速查找。这通常工作正常。Set<String>blacklist.contains(a+b+c)

问题：黑名单定义中的 3 个参数中除一个参数外的任何一个都可能被 wildcarted。因此，黑名单可能包含：*

OneTwoThree

*bc

因此，该方法调用 。旁注：方法输入参数当然可能不是通配符，而只是普通的字符串词。isBlacklisted("One", "b", "c") = true

问题是：我怎样才能更好地编写查找，如下所示？

private Set<String> blacklist; //concatenation of 3 fields 'a+b+c'

private boolean isBlacklisted(String a, String b, String c) {

    return blacklist.contains(a+b+c)

        || blacklist.contains("*"+b+c)

        || blacklist.contains(a+"*"+c)

        || blacklist.contains(a+b+"*")

        || blacklist.contains("**"+c)

        || blacklist.contains(a+"**")

        || blacklist.contains("*"+b+"*");

}

如何创建支持通配符的快速筛选器，而不必像我一样检查所有可能的串联通配符？

Answer 1

当你写*时，你的意思是像“任何字符串”？如果是 - 只需使用正则表达式：for (String blacklist : blackRegex){&nbsp; &nbsp; Pattern p = Pattern.compile(blackRegex);&nbsp; &nbsp; Matcher matcher = p.matcher(string);&nbsp; &nbsp; if (matcher.find()&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;return true;&nbsp; &nbsp; }}return false;blackRegex的一个例子是（someA）（someB）.*使用.*而不是*对于任何字符串，你可以按照java正则表达式指南。

Answer 2

定义一个黑名单规则类：class BlackListRule {&nbsp; &nbsp; private String a;&nbsp; &nbsp; private String b;&nbsp; &nbsp; private String c;&nbsp; &nbsp; BlackListRule(String a, String b, String c) {&nbsp; &nbsp; &nbsp; &nbsp; this.a = a; this.b = b; this.c = c;&nbsp; &nbsp; }&nbsp; &nbsp; public boolean matches(String a, String b, String c) {&nbsp; &nbsp; &nbsp; &nbsp; return ("*".equals(this.a) || this.a.equals(a))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&&("*".equals(this.b) || this.b.equals(b))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&&("*".equals(this.c) || this.c.equals(c));&nbsp; &nbsp; }&nbsp; &nbsp; public int hashCode() {&nbsp; &nbsp; &nbsp; &nbsp; return Arrays.deepHashCode(new char[][]{a.toCharArray(), b.toCharArray(), c.toCharArray()});&nbsp; &nbsp; }&nbsp; &nbsp; public boolean equals(Object o) {&nbsp; &nbsp; &nbsp; &nbsp; return o instanceof BlackListRule && ((BlackListRule)o).hashCode() == hashCode();&nbsp; &nbsp; }}private Set<BlackListRule> blacklist;private boolean isBlacklisted(String a, String b, String c) {&nbsp; &nbsp; return blacklist.stream().anyMatch(rule -> rule.matches(a,b,c));}这是一个最小的工作示例，你绝对应该改进它，但你明白了。你可以在这里试试。

Answer 3

多亏了您的所有建议，我总结如下（假设黑名单定义来自db）：对于每个“abc”黑名单元组，我创建了一个正则表达式模式。然后将这些模式与 OR 连接。|private void init(SqlRowSet set) {&nbsp; &nbsp; &nbsp; &nbsp; Set<String> patterns = new HashSet<>();&nbsp; &nbsp; &nbsp; &nbsp; while (set.next()) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String a = set.getString(1);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String b = set.getString(2);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String c = set.getString(3);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; patterns.add(a + "/" + b + "/" + c);&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; regex = Pattern.compile(String.join("|", patterns));}private boolean isBlacklisted(String a, String b, String c) {&nbsp; &nbsp; return regex.matcher(a+"/"+b+"/"+c).matches();}现在，我可以创建我的黑名单，并将其与之匹配。a, b, .*isBlacklisted("a", "b", "anything") = true