如何在java中逃避$？

Question

我正在尝试下面的代码,但得到错误

String x = "aaa XXX bbb";
    String replace = "XXX";
    String y = "xy$z";
    String z=y.replaceAll("$", "\\$");
    x = x.replaceFirst(replace, z);
    System.out.println(x);

错误

Exception in thread "main" java.lang.IllegalArgumentException: Illegal group reference
    at java.util.regex.Matcher.appendReplacement(Unknown Source)
    at java.util.regex.Matcher.replaceFirst(Unknown Source)
    at java.lang.String.replaceFirst(Unknown Source)
    at Test.main(Test.java:10)

我希望结果为

aaa xy$z bbb

Answer 1

replace()相反,使用不使用正则表达式,因为您根本不需要它们:

String x = "aaa XXX bbb";
String replace = "XXX";
String y = "xy$z";
x = x.replace(replace, y);
System.out.println(x);

这将按aaa xy$z bbb预期打印.