Java中是否有一种方法可以用给定的字符串替换第一次出现的字符串？ [复制]答案

【问题标题】：Is there a method in Java that will replace the first occurrence of a String with a given String? [duplicate]Java中是否有一种方法可以用给定的字符串替换第一次出现的字符串？ [复制]
【发布时间】：2020-03-24 11:04:22
【问题描述】：

我正在尝试用 Java 编写一个 madlibs 程序。有一个方法接受模板字符串、该字符串中所有占位符的 ArrayList 以及将替换这些模板的所有用户输入的 ArrayList 作为参数。

方法如下：

private String replacePlaceHolder(String template, ArrayList<String> placeholders, ArrayList<String> replacements){
        for (int i = 0; i < placeholders.size(); i++){
            template = template.replace(placeholders.get(i), replacements.get(i));
        }
        return template;
    }

问题是，该方法是用替换替换所有出现的给定模板，例如“[形容词]”，而不仅仅是第一个。我尝试改用template = template.replaceFirst(placeholders.get(i), replacements.get(i))，但它用所有用户输入替换了第一个占位符，并忽略了其余部分。

这是我使用的模板：

Computer programming, also known as [-ing Verb], is a
process that leads from a [Adjective] problem 
to an executable [Noun]. 
Programming often involves [-ing Verb], 
[-ing Verb], and [-ing Verb], and can be learned
by anyone!
Source code is written in a programming language, 
such as [Animal]code, or Java.
The first ever programmer was [Name of Celebrity], 
who invented [Plural Noun] in the year [Year]. 
Since then, programming has become a 
[Adjective] practice all across the world.

我知道占位符的 ArrayList 与模板中的占位符匹配，并且该 ArrayList 与用户输入的 ArrayList 长度相同。

我应该做些什么不同的事情？

【问题讨论】：

@kaya3 我试过replaceFirst() 没用，所以我不相信这个问题是重复的。
好吧，你的问题是如何替换第一次出现而不是每次出现，所以它是重复的。如果这不起作用，那么您可能想做其他事情，与您在问题中要求的不同。

标签： java arraylist string-algorithm

【解决方案1】：

replaceFirst是正确答案，但是参数是正则表达式，所以你需要引用搜索文本，特别是因为它使用[]，这是一个字符类的特殊正则表达式。

要引用这些值，请使用Pattern.quote(String s) 作为第一个参数，使用Matcher.quoteReplacement(String s) 作为第二个参数。

private static String replacePlaceHolder(String template, List<String> placeholders, List<String> replacements) {
    for (int i = 0; i < placeholders.size(); i++){
        template = template.replaceFirst(Pattern.quote(placeholders.get(i)),
                                         Matcher.quoteReplacement(replacements.get(i)));
    }
    return template;
}

这是一个Minimal, Reproducible Example，你应该在问题中提供一些东西：

String template = "Computer programming, also known as [-ing Verb], is a\n" +
                  "process that leads from a [Adjective] problem\n" +
                  "to an executable [Noun].\n" +
                  "Programming often involves [-ing Verb],\n" +
                  "[-ing Verb], and [-ing Verb], and can be learned\n" +
                  "by anyone!\n" +
                  "Source code is written in a programming language,\n" +
                  "such as [Animal]code, or Java.\n" +
                  "The first ever programmer was [Name of Celebrity],\n" +
                  "who invented [Plural Noun] in the year [Year].\n" +
                  "Since then, programming has become a\n" +
                  "[Adjective] practice all across the world.";
List<String> placeholders = Arrays.asList(
        "[-ing Verb]", "[Adjective]", "[Noun]",
        "[-ing Verb]", "[-ing Verb]", "[-ing Verb]",
        "[Animal]", "[Name of Celebrity]", "[Plural Noun]",
        "[Year]", "[Adjective]" );
List<String> replacements = Arrays.asList(
        "AA", "BB", "CC",
        "DD", "EE", "FF",
        "GG", "HH", "II",
        "JJ", "KK" );
String result = replacePlaceHolder(template, placeholders, replacements);
System.out.println(result);

输出

Computer programming, also known as AA, is a
process that leads from a BB problem
to an executable CC.
Programming often involves DD,
EE, and FF, and can be learned
by anyone!
Source code is written in a programming language,
such as GGcode, or Java.
The first ever programmer was HH,
who invented II in the year JJ.
Since then, programming has become a
KK practice all across the world.

【讨论】：