你在做一个 replaceAll 调用，只会将它们设置为相同的值。如果希望每个字符单独考虑，则需要为每个字符随机计算和选择，然后用它重新生成一个新字符串。

import java.util.List;
import java.util.Random;

public class DyslexiaExample
{
  public static void main(String[] args) {
    System.out.println(simulateDyslexia("Some possible bountiful quotes."));
  }

  public static String simulateDyslexia(String sentence) {
    List<Character> vals = List.of('d', 'b', 'q', 'p');
    StringBuilder builder = new StringBuilder();

    Random random = new Random();

    for(char c : sentence.toCharArray()) {
      if(vals.contains(c)) {
        builder.append(vals.get(random.nextInt(vals.size())));
      }
      else {
        builder.append(c);
      }
    }

    return builder.toString();
  }
}

样本输出： Some bossible dountiful buotes. 如果您想在哪个字母与另一个字母交换之间保持一致，那么可以考虑生成一个Map。

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DyslexiaExample
{
  public static void main(String[] args) {
    System.out.println(simulateDyslexia("And quite possibly even more boisterous bountiful quotes."));
  }

  public static String simulateDyslexia(String sentence) {
    List<Character> vals = List.of('d', 'b', 'q', 'p');
    StringBuilder builder = new StringBuilder();

    List<Character> shuffleVals = new ArrayList<>(vals);
    Collections.shuffle(shuffleVals);

    Map<Character, Character> swapMap = new HashMap<>();
    for(int i = 0; i < vals.size(); i++)
      swapMap.put(vals.get(i), shuffleVals.get(i));

    for(char c : sentence.toCharArray()) {
      if(swapMap.keySet().contains(c)) {
        builder.append(swapMap.get(c));
      }
      else {
        builder.append(c);
      }
    }

    return builder.toString();
  }
}

样本输出： Anb puite dossiqly even more qoisterous qountiful puotes.