将以逗号分隔的id字符串按每20个id截取分组

       我这里id字符串形如：

String a="1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30"+",31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62";

    因为我们有一个按id批量查询的接口，查询的id之间用逗号隔开，但一次最多支持查询20个；而我每次查询所用到的id是从消息队列里面取出来的，数量可能远大于20个，所以要每隔20个id截取一下，分批查询，工具类如下：

public static void intercept(String a){        String [] b=a.split(",");    int splitLength=20;    int start=0;    int end=start+splitLength;    while (end<b.length){        StringBuilder builder=new StringBuilder();        for (int i = start; i < end; i++) {            builder.append(b[i] + ",");        }        String str=builder.toString();        String c=str.substring(0,str.lastIndexOf(","));        System.out.println(c);        start=end;        end=end+splitLength;    }    if(start<=b.length){        StringBuilder builder=new StringBuilder();        for (int i = start; i <b.length; i++) {            builder.append(b[i] + ",");        }        String c=builder.substring(0,builder.lastIndexOf(","));        System.out.println(c);    }

    将如上a字符串传入这个方法后，控制台运行结果为：

1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40
41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60
61,62

    如果用在生产环境，在方法中再添加一个list，截取好的都放进list中返回就行了；然后循环list，传入截取好的id列表去查询接口