把十六进制字符串转十进制数值

public static int covert(String content){
        int number=0;
        String [] HighLetter = {"A","B","C","D","E","F"};
        Map<String,Integer> map = new HashMap<>();
        for(int i = 0;i <= 9;i++){
            map.put(i+"",i);
        }
        for(int j= 10;j<HighLetter.length+10;j++){
            map.put(HighLetter[j-10],j);
        }
        String[]str = new String[content.length()];
        for(int i = 0; i < str.length; i++){
            str[i] = content.substring(i,i+1);
        }
        for(int i = 0; i < str.length; i++){
            number += map.get(str[i])*Math.pow(16,str.length-1-i);
        }
        return number;
    }

第二种方法：
int sint = new BigInteger(str.substring(6,10), 16).intValue();