删除字符串相邻两个元素---java

实现一个方法，给定一个输入字符串，能够删除所有连续同样字母（大小写不敏感）。例如，输入为ABBCCCCCBBAB，输出就是 ABCBAB

import java.util.ArrayList;
import java.util.stream.Collectors;

public class DemoTen {
   public static void main(String[] args){
        String str1 = "ABBCCCCCBBAB";
        String str2 = "aAC";
        String aa =dele(str1);
        String bb =dele(str2);
        System.out.println(aa);
        System.out.println(bb);
    }

private static String dele(String str1) {
	String s1 = str1.toUpperCase();
	int i=0,j=1;
	ArrayList<Object> arrayList = new ArrayList<Object>();
	for(int k=0;k<s1.length();k++) {
		arrayList.add(s1.charAt(k));
	}
	System.out.println(arrayList.toString());
	while(i<j&&i<arrayList.size()&&j<arrayList.size()) {
		if(arrayList.get(i).equals(arrayList.get(j))) {
			arrayList.remove(j);
		}else {
			i++;
			j++;
		}
	}
	String list = arrayList.stream().map(Object::toString).collect(Collectors.joining(""));
	return list;
}
 
}

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.stream.Collectors;

import org.junit.platform.commons.util.StringUtils;

public class DemoTen {
   public static void main(String[] args){
        String str1 = "ABBCCCCCBBAB";
        String str2 = "aAC";
        StringBuilder aa =dele(str1);
        StringBuilder bb =dele(str2);
        System.out.println(aa);
        System.out.println(bb);
    }

private static StringBuilder dele(String str1) {
	String s1 = str1.toUpperCase();
	int i=0,j=1;
	ArrayList<Object> arrayList = new ArrayList<Object>();
	for(int k=0;k<s1.length();k++) {
		arrayList.add(s1.charAt(k));
	}
	System.out.println(arrayList.toString());
	while(i<j&&i<arrayList.size()&&j<arrayList.size()) {
		if(arrayList.get(i).equals(arrayList.get(j))) {
			arrayList.remove(j);
		}else {
			i++;
			j++;
		}
	}
	StringBuilder stringBuilder = new StringBuilder();
	for(Object character:arrayList) {
		stringBuilder.append(character);
	}
	return stringBuilder;
	}
}