如果关键短语是一个独立的单词，我该如何替换它？

Question

例如，如果我要制作关键短语＆＃34; ball＆＃34;，那么我需要一个句子＆＃34;他因为正在打棒球而接球＃34;到了＃34;他抓住了XXXX，因为他正在打棒球＆＃34;。相反，我得到了＆＃34;他抓住了XXXX，因为他正在玩baseXXXX＆＃34;。我正在使用replaceAll，这就是我收到此错误的原因，但我想知道是否有办法让我检查之后是否有空白字符，以及如果有空格或特殊字符，则只替换该单词。我挣扎的原因是因为如果跟着一个特殊的字符，而不是一个字母，我仍然想要替换这个词。

Answer 1

你可以使用boundary matcher（注意你必须逃避反斜杠）。边界\b一词也处理标点符号：

System.out.println("He caught the ball because he was playing baseball"
            .replaceAll("\\bball\\b", "XXXX"));
System.out.println("One ball, two cats. Two cats with a ball."
            .replaceAll("\\bball\\b", "XXXX"));
System.out.println("A ball? A ball!".replaceAll("\\bball\\b", "XXXX"));

打印：

He caught the XXXX because he was playing baseball
One XXXX, two cats. Two cats with a XXXX.
A XXXX? A XXXX!

Answer 2

试试这个：

    String s = "He caught the ball because he was playing baseball";
    String replaceKey = "ball";
    String replaceValue = "XXXX";

    String[] sArray = s.split(" ");

    String finalS = "";
    for(int i=0; i<sArray.length;i++) {
        if(replaceKey.equals(sArray[i])){
            sArray[i] = replaceValue;
        }
    }

    System.out.println(String.join(" ", sArray));

输出：He caught the XXXX because he was playing baseball

修改

    String s = "!ball! ?ball1 ball! ball1 ball, 1ball1 baseball ba.ll";
    String replaceKeyPattern = "^[\\W+[ball]\\W+]+$";
/*    \\W is all non word characters= special characters */

    String replaceKey = "ball";
    String replaceValue = "XXXX";

    String[] sArray = s.split(" ");

    String finalS = "";
    for(int i=0; i<sArray.length;i++) {
        if(sArray[i].matches(replaceKeyPattern)){
            sArray[i] = sArray[i].replace(replaceKey,replaceValue);
        }
    }

    System.out.println(String.join(" ", sArray));

输出：!XXXX! ?ball1 XXXX! ball1 XXXX, 1ball1 baseball ba.ll

希望它有所帮助！