英文:
java String replace characters
问题
我需要你的帮助解决一个棘手的问题。
我有一个如下的 映射（map）：
Map<Integer, String> ruleMap = new HashMap<>();ruleMap.put(1, "A");ruleMap.put(12, "Test - 12");ruleMap.put(1012, "Test Metadata 12 A");
然后我有一个 规则（rule），我要在其中分离出 ID 并将它们收集到一个列表中。通过迭代列表，我将其中的 ID 替换为映射中相应的值。
代码：
String rule = "1 AND 12 OR 1012 AND 12 or 1012";List<String> idList = new ArrayList<>();Pattern p = Pattern.compile("[0-9]+");Matcher m = p.matcher(rule);while (m.find()) {idList.add(m.group());}for (String id : idList) {if (ObjectUtils.isNonEmpty(ruleMap.get(Integer.parseInt(id)))) {rule = rule.replaceFirst(id, ruleMap.get(Integer.parseInt(id)));}}System.out.println(rule);
我得到的输出是这样的：
A AND Test - Test - 12 OR Test Metadata 12 A AND 12 or Test Metadata 12 A
正如你所看到的，在第一次迭代中，id 12 被替换为了其对应的值，但在第二次出现 id 12 时，值从 Test - 12 替换为了 Test - Test - 12。
所以，有谁可以帮我解决这个问题吗？
英文:
I need your help for one tricky problem.
I have one map like below
Map<Integer, String> ruleMap = new HashMap<>();ruleMap.put(1, "A");ruleMap.put(12, "Test - 12");ruleMap.put(1012, "Test Metadata 12 A");
and I have one rule in which I am separating ids and collecting them into a list. By iterating over the list, I am replacing its ids by its respective value from map.
code :
String rule = "1 AND 12 OR 1012 AND 12 or 1012";List < String > idList = new ArrayList < > ();Pattern p = Pattern.compile("[0-9]+");Matcher m = p.matcher(rule);while (m.find()) {idList.add(m.group());}for (String id: idList) {if (ObjectUtils.isNonEmpty(ruleMap.get(Integer.parseInt(id)))) {rule = rule.replaceFirst(id, ruleMap.get(Integer.parseInt(id)));}}System.out.println(rule);
I am getting output like this -
A AND Test - Test - 12 OR Test Metadata 12 A AND 12 or Test Metadata 12 A
as you can see for the first iteration of id 12 replaced its respected value but on the second occurrence of the id 12 replaced the value Test - 12 to Test - Test - 12.
So can anyone help me with this?
答案1
得分: 4
你需要进行带有适当单词边界的正则表达式替换。我建议继续使用正则表达式迭代器（就像你之前已经在做的那样），但是使用模式 \b\d+\b 仅匹配完整的数字字符串。然后，在每次匹配时，根据数字是否存在，在规则映射中查找替换值。使用 Matcher#appendReplacement 在处理过程中逐步构建替换字符串。
Map<String, String> ruleMap = new HashMap<>();ruleMap.put("1", "A");ruleMap.put("12", "Test - 12");ruleMap.put("1012", "Test Metadata 12 A");String rule = "1 AND 12 OR 1012 AND 12 or 1012";Pattern pattern = Pattern.compile("\\b\\d+\\b");Matcher m = pattern.matcher(rule);StringBuffer buffer = new StringBuffer();while(m.find()) {if (ruleMap.containsKey(m.group(0))) {m.appendReplacement(buffer, ruleMap.get(m.group(0)));}}m.appendTail(buffer);System.out.println(rule + "\n" + buffer.toString());
这将打印出：
1 AND 12 OR 1012 AND 12 or 1012A AND Test - 12 OR Test Metadata 12 A AND Test - 12 or Test Metadata 12 A
英文:
You need to be doing regex replacement with proper word boundaries. I suggest using a regex iterator (as you were already doing), but use the pattern \b\d+\b to match only full number strings. Then, at each match, do a lookup in the rule map, if the number be present, to find a replacement value. Use Matcher#appendReplacement to build out the replacement string as you go along.
Map<String, String> ruleMap = new HashMap<>();ruleMap.put("1", "A");ruleMap.put("12", "Test - 12");ruleMap.put("1012", "Test Metadata 12 A");String rule = "1 AND 12 OR 1012 AND 12 or 1012";Pattern pattern = Pattern.compile("\\b\\d+\\b");Matcher m = pattern.matcher(rule);StringBuffer buffer = new StringBuffer();while(m.find()) {if (ruleMap.containsKey(m.group(0))) {m.appendReplacement(buffer, ruleMap.get(m.group(0)));}}m.appendTail(buffer);System.out.println(rule + "\n" + buffer.toString());
This prints:
1 AND 12 OR 1012 AND 12 or 1012A AND Test - 12 OR Test Metadata 12 A AND Test - 12 or Test Metadata 12 A
答案2
得分: 1
如果您恰好使用Java 9或更高版本，您还可以使用Matcher#replaceAll：
Map<Integer, String> ruleMap = new HashMap<>();ruleMap.put(1, "A");ruleMap.put(12, "Test - 12");ruleMap.put(1012, "Test Metadata 12 A");String rule = "1 AND 12 OR 1012 AND 12 or 1012";rule = Pattern.compile("\\b\\d+\\b").matcher(rule).replaceAll(m -> ruleMap.getOrDefault(Integer.parseInt(m.group()), m.group()));System.out.println(rule);
英文:
If you happen to use Java 9 or higher you could also use Matcher#replaceAll:
Map<Integer, String> ruleMap = new HashMap<>();ruleMap.put(1, "A");ruleMap.put(12, "Test - 12");ruleMap.put(1012, "Test Metadata 12 A");String rule = "1 AND 12 OR 1012 AND 12 or 1012";rule = Pattern.compile("\\b\\d+\\b").matcher(rule).replaceAll(m -> ruleMap.getOrDefault(Integer.parseInt(m.group()), m.group()));System.out.println(rule);
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