@Test
public void test1(){
   String content1 = "AAAAAAAAAAAAAAAAAAAAAAAAttBffgfaaddddddsCDaaaBBBBdddfdsgggggg";
   String result = yasuo(content1);
    System.out.println(result);
}

public String yasuo(String content){
    content = content +" ";
    StringBuilder builder = new StringBuilder();
    int time = 1;
    for(int i=0;i<content.length()-1;i++){
        String s = content.charAt(i)+"";
        String next = content.charAt(i+1)+"";
        if(s.matches("\"^[0-9]*$")){
            builder.append(s);
        }
        if(s.equals(next)){
            time+=1;
        }else{
            if(time!=1){
                builder.append(time+s);
                time = 1;
                continue;
            }
            builder.append(s);
        }
    }
    return builder.toString();
}

打印结果：