您可以创建一个字符映射作为键和值，然后像这样逐个字符地循环遍历:

You can create a Map of Character as key and value, then loop over character by character like so :

String text = "RHKKA";
Map<Character, Character> map = new HashMap<>();
map.put('R', 'H');
map.put('H', 'E');
map.put('K', 'L');
map.put('A', 'O');
char[] chars = text.toCharArray();
for (int i = 0; i < chars.length; i++) {
    chars[i] = map.get(chars[i]);
}
String result = String.valueOf(chars);
System.out.println(result.toString());//HELLO

Java8 +可能的解决方案

或者，如果您使用的是Java8 +，则可以使用:

Java8+ possible solution

Or if you are using Java8+ you can use :

String result = text.chars()
        .mapToObj(c -> String.valueOf(map.get((char) c)))
        .collect(Collectors.joining());//HELLO

Java9 +可能的解决方案

使用

Java9+ possible solution

Another possible solution if to use Matcher::replaceAll like so :

String text = "RHKKA";
Map<Character, Character> map = Map.of('R', 'H', 'H', 'E', 'K', 'L', 'A', 'O');
text = Pattern.compile(".").matcher(text)
        .replaceAll(c -> String.valueOf(map.get(c.group().charAt(0))));//HELLO

您可以阅读有关 Map.of