在String中搜索并获取相同的字符

Question

我需要在另一个逐个字符的字符串中搜索某个字符串，如果字符相同则得到这样的字符;

我是这样做的

public String searchForSignature(String texto2) throws NoSuchAlgorithmException {
        String myString = "", foundString = "";
        myString = "aeiousrtmvb257";
        for (int i = 0; i < texto2.length() || i <= 1000; i++) {
            char c = texto2.charAt(i);

            for (int j = 0; j < myString.length(); j++) {
                if (c == myString.charAt(j)) {
                    foundString = foundString + c;
                }
            }
        }
        return foundString;
}

我想提高性能，看到有形式和使用正则表达式，因为我仍然有点躺着，我不能像我那样成功。

 public String searchForSignature2(String texto2) {
        Pattern pattern = Pattern.compile("aeiousrtmvb257");
        Matcher matcher = pattern.matcher(texto2);
        while (matcher.find()) {
            System.out.println(matcher.group(1));
        }
        return matcher.group(1).toString();
    }

不归还任何东西

//编辑

真的，我想我对这个问题不太清楚。实际上我需要让所有字符等于“aeiousrtmvb257”字符串中的字符

我这样做了，现在看来还行，我只是不知道表现是否令人满意。

 public String searchForSignature2(String texto2) {
        String foundString = "";
        Pattern pattern = Pattern.compile("[aeiousrtmvb257]");
        Matcher matcher = pattern.matcher(texto2);
        while (matcher.find()) {
            System.out.println(matcher.group());
            foundString+=matcher.group();
        }
        return foundString;
    }
}

Answer 1

据我了解你的问题，通过使用Patternand Matcher这应该做的伎俩：

码

private static final String PATTERN_TO_FIND = "[aeiousrtmvb257]";

public static void main(String[] args) {
    System.out.println(searchForSignature2("111aeiousrtmvb257111"));
}

public static String searchForSignature2(String texto2) {
    Pattern pattern = Pattern.compile(PATTERN_TO_FIND);
    Matcher matcher = pattern.matcher(texto2);

    StringBuilder result = new StringBuilder();

    while (matcher.find()) {
        result.append(matcher.group());
    }

    return result.toString();
}

产量

aeiousrtmvb257

Answer 2

我不知道texto2.length() || i <= 1000背后的原因是什么，但基于你方法中的逻辑，我可以建议以下解决方案：

public static void main(String... args) throws IOException {
    System.out.println(searchForSignature("hello"));
}

public static String searchForSignature(String texto2) {
    String myString = "aeiousrtmvb257";
    StringBuilder builder = new StringBuilder();
    for (char s : texto2.toCharArray()) {
        if (myString.indexOf(s) != -1) {
            builder.append(s);
        }
    }

    return builder.toString();
}

输出：eo

Answer 3

我不明白，为什么要打印你找到的字符串

public static String searchForSignature2(String texto2) {
    String maaString = "aeiousrtmvb257";
    String toSearch = ".*" + maaString +".*";
    boolean b = Pattern.matches(toSearch, texto2);

    return b ? maaString : "";
  }

public static void main(String[] args)
{
    String input = "4erdhrAW BLBAJJINJOI WETSEKMsef saemfosnens3bntu is5o3n029j29i30kwq23eki4"+
    "maoifmakakmkakmsmfajiwfuanyi  gaeniygaenigaenigeanige anigeanjeagjnageunega"+
    "movmmklmklzvxmkxzcvmoifsadoi asfugufngs"+
    "wpawfmaopfwamopfwampfwampofwampfawmfwamokfesomk"+
    "3rwq3rqrq3rqetgwtgwaeiousrtmvb2576266wdgdgdgdgd";
    String myString = searchForSignature2(input);
    System.out.println(myString);
}

你需要添加。*来告诉你的字符串被任何字符包围