java - 使用正则表达式中的反向引用动态替换文本

Question

我想像使用整数一样使用 $1 值。
这个想法是用等效的数组值替换原始文本中的所有数字并创建一个新文本。
下面期望的结果应该是“这是 DBValue4，这是 DBValue2，这是 DBValue7”
另外，有没有办法保存这些反向引用以供进一步使用？

String[] values = {"DBValue0","DBValue1","DBValue2","DBValue3","DBValue4","DBValue5","DBValue6","DBValue7","DBValue8","DBValue9","DBValue10"};
String originaltext = "This is 4, This is 2, This is 7";
text = originaltext.replaceAll("(\\d)","$1");
// want something like
text = originaltext.replaceAll("(\\d)",values[$1]);
//or
text = originaltext.replaceAll("(\\d)",values[Integer.parseInt("$1")]);

Answer 1

您可以使用 Pattern和 Matcher像这样:

public static void main(String[] args) throws Exception {
    final String[] values = {"DBValue0", "DBValue1", "DBValue2", "DBValue3", "DBValue4", "DBValue5", "DBValue6", "DBValue7", "DBValue8", "DBValue9", "DBValue10"};
    final String originaltext = "This is 4, This is 2, This is 7";
    final Pattern pattern = Pattern.compile("(?<=This is )\\d++");
    final Matcher matcher = pattern.matcher(originaltext);
    final StringBuffer sb = new StringBuffer();
    while (matcher.find()) {
        System.out.println(matcher.group());
        final int index = Integer.parseInt(matcher.group());
        matcher.appendReplacement(sb, values[index]);
    }
    matcher.appendTail(sb);
    System.out.println(sb);
}

输出:

4
2
7
This is DBValue4, This is DBValue2, This is DBValue7

编辑

除了 OP 的评论之外，似乎 OP 需要替换 String形式为 {name, index} 的小号其中“name”是数组的名称，“index”是该数组中元素的索引。

这很容易通过 Map 实现使用 Map<String, String[]> 将数组 ping 到它们的名称然后使用 Pattern首先捕获 name然后是 index .

public static void main(String[] args) throws Exception {
    final String[] companies = {"Company1", "Company2", "Company3"};
    final String[] names = {"Alice", "Bob", "Eve"};
    final String originaltext = "This is {company, 0}, This is {name, 1}, This is {name, 2}";
    final Map<String, String[]> values = new HashMap<>();
    values.put("company", companies);
    values.put("name", names);
    final Pattern pattern = Pattern.compile("\\{([^,]++),\\s*+(\\d++)}");
    final Matcher matcher = pattern.matcher(originaltext);
    final StringBuffer sb = new StringBuffer();
    while (matcher.find()) {
        System.out.println(matcher.group(1));
        System.out.println(matcher.group(2));
        final int index = Integer.parseInt(matcher.group(2));
        matcher.appendReplacement(sb, values.get(matcher.group(1))[index]);
    }
    matcher.appendTail(sb);
    System.out.println(sb);
}

输出:

company
0
name
1
name
2
This is Company1, This is Bob, This is Eve