替换字符串中的变量占位符

您应该使用

StringBuffer

Matcher.appendReplacement

Matcher.appendTail

这是一个完整的示例：

String msg = "Hello [Start Date + 30] world [ Start Date ].";StringBuffer sb = new StringBuffer();Matcher m = Pattern.compile("\[(.*?)\]").matcher(msg);while (m.find()) {    // What to replace    String toReplace = m.group(1);    // New value to insert    int toInsert = 1000;    // Parse toReplace (you probably want to do something better :)    String[] parts = toReplace.split("\+");    if (parts.length > 1)        toInsert += Integer.parseInt(parts[1].trim());    // Append replaced match.    m.appendReplacement(sb, "" + toInsert);}m.appendTail(sb);System.out.println(sb);

输出：

Hello 1030 world 1000.