替换字符串中的多个子字符串 [英] replace multiple sub-strings in a string
问题描述
此函数用于将字符串中的某些子字符串替换为相应的值。
This function is used to replace certain substrings in a string with respective values.
// map(string_to_replace,string_to_replace_with)
// map(string_to_replace, string_to_replace_with)
String template = "ola ala kala pala sala";
StringBuilder populatedTemplate = new StringBuilder();
HashMap<String, String> map = new HashMap<>();
map.put("ola", "patola");
map.put("pala", "papala");
int i=0;
for (String word : template.split("'")) {
populatedTemplate.append( map.getOrDefault(word, word));
populatedTemplate.append(" ");
}
System.out.println(populatedTemplate.toString());
如果要替换的子字符串被(空格)包围,以上功能将正常工作。
This above function works fine if substring to be replaced is surrounded by " "(space).
Ex- String =>嘿{how} are $ = you
如果要替换的子字符串是嘿或你,那么工作正常。问题是当我想替换如何和你。
Ex- String => "Hey {how} are $=you" if substrings to be replaced is "Hey" or "you", then it works fine. The issue is when I want to replace "how" and "you".
如何在没有额外复杂性的情况下实现此目的?
How can I achieve this without additional complexity ?
推荐答案
我想只替换您在地图上的单词,并保留其余的字样,您可以继续如下:
I you want to replace only the words that you have in the map and keep the rest as it is, you can proceed as next:
String template = "Hey {how} are $=you";
StringBuilder populatedTemplate = new StringBuilder();
Map<String, String> map = new HashMap<>();
map.put("how", "HH");
map.put("you", "YY");
// Pattern allowing to extract only the words
Pattern pattern = Pattern.compile("\\w+");
Matcher matcher = pattern.matcher(template);
int fromIndex = 0;
while (matcher.find(fromIndex)) {
// The start index of the current word
int startIdx = matcher.start();
if (fromIndex < startIdx) {
// Add what we have between two words
populatedTemplate.append(template, fromIndex, startIdx);
}
// The current word
String word = matcher.group();
// Replace the word by itself or what we have in the map
populatedTemplate.append(map.getOrDefault(word, word));
// Start the next find from the end index of the current word
fromIndex = matcher.end();
}
if (fromIndex < template.length()) {
// Add the remaining sub String
populatedTemplate.append(template, fromIndex, template.length());
}
System.out.println(populatedTemplate);
输出:
Hey {HH} are $=YY
响应更新:
假设你想要不仅可以替换单词,而且可以替换 $ {questionNumber}
,您将需要动态创建正则表达式:
Assuming that you want to be able to replace not only words but anything like ${questionNumber}
, you will need to create the regular expression dynamically like this:
String template = "Hey {how} are $=you id=minScaleBox-${questionNumber}";
...
map.put("${questionNumber}", "foo");
StringBuilder regex = new StringBuilder();
boolean first = true;
for (String word : map.keySet()) {
if (first) {
first = false;
} else {
regex.append('|');
}
regex.append(Pattern.quote(word));
}
Pattern pattern = Pattern.compile(regex.toString());
...
输出:
Hey {HH} are $=YY id=minScaleBox-foo
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