Java：在基于正则表达式的HashMap键中搜索？ [英] Java: Search in HashMap keys based on regex?

问题描述

我使用HashMap来构建同义词库来存储同义词。

我试图通过基于正则表达式的单词进行搜索：该方法必须将字符串作为参数并返回结果数组。这是我第一次刺穿它：

  public ArrayList< String> searchDefinition（String regex）{
 ArrayList< String> results = new ArrayList< String>（）; 
 
模式p = Pattern.compile（正则表达式）; 
 
 Set< String> keys = thesaurus.keySet（）; 
 Iterator< String> ite = keys.iterator（）; $（b）b 
 while（ite.hasNext（））{
 String candidate = ite.next（）; 
 Matcher m = p.matcher（候选人）; 
 System.out.println（试图匹配：+ candidate +到+ regex）; 
 if（m.matches（））{
 System.out.println（it matches）; 
 results.add（候选人）; 
} 
} 
 
 if（results.isEmpty（））{
 return null; 
} 
其他{
返回结果; 
 
 
 
 
 
 
 $ b现在，这不起作用，因为我期望或者我错误地使用了正则表达式）。如果我在hashmap中有下列键：
  cat，car，chopper 
  
然后通过调用 searchDefinition（c）或 searchDefinition（ 
 $ b 
 
 
如何按预期完成这项工作？
 
 
是否有比HashMap更好的数据结构来保持图类似于同义词库？ （只有好奇心，因为这个任务我们被要求使用Java集合映射）。
 
我在上面的代码中做了什么不恰当的事情？
 
 
谢谢，
 Dan 
 
 
 
编辑：我已更正示例。即使我使用了正确的大小写，它也不起作用。
解决方案
您需要指定大小写不敏感 Pattern.compile  （c，  Pattern.CASE_INSENSITIVE  ）。要查找带有 c 的单词，您需要使用 matcher.find（）。  Matcher.matches（）试图匹配整个字符串。
 
I'm building a thesaurus using a HashMap to store the synonyms. 

I'm trying to search through the words based on a regular expression: the method will have to take a string as parameter and return an array of results. Here's my first stab at it:
public ArrayList<String> searchDefinition(String regex) {
    ArrayList<String> results = new ArrayList<String>();

    Pattern p = Pattern.compile(regex);

    Set<String> keys = thesaurus.keySet();
    Iterator<String> ite = keys.iterator();

    while (ite.hasNext()) {
        String candidate = ite.next();
        Matcher m = p.matcher(candidate);
        System.out.println("Attempting to match: " + candidate + " to "  + regex);
        if (m.matches()) {
            System.out.println("it matches");
            results.add(candidate);
        }
    }   

    if (results.isEmpty()) {
        return null;
    }
    else {
        return results;
    }
}
Now, this does not work as I would expect (or maybe I'm using regular expressions incorrectly). If I have the following keys in the hashmap:
cat, car, chopper
then by calling searchDefinition("c") or searchDefinition("c*") I get null.

How do I make this work as expected?
Is there a better data structure than HashMap to keep a graph like needed by a thesaurus? (curiosity only, as for this assignment we're asked to use Java Collection Map).
Anything else I'm doing innapropriately in the code above?
Thanks,
Dan

EDIT: I've corrected the example. It doesn't work even if I use the correct case.
解决方案
You need to specify case insensitivity Pattern.compile( "c",Pattern.CASE_INSENSITIVE ). To find a word with a c in it you need to use matcher.find(). Matcher.matches() tries to match the whole string.

                        
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