public?class?demo01?{
????public?static?byte[]?int2Bytes(int?id)?{
????????byte[]?arr?=?new?byte[4];

????????for?(int?i?=?0;?i?<?arr.length;?i++)?{
????????????arr[i]?=?(byte)?(int)?((id?>>?i?*?8)?&?0xff);
????????}
????????return?arr;
????}

????public?static?int?byte2Int(byte[]?arr)?{
????????int?result?=?0;
????????for?(int?i?=?0;?i?<?arr.length;?i++)?{
????????????int?s?=?(int)?((arr[i]?&?0xff)?<<?i?*?8);
????????????result?=?result?+?s;
????????}
????????return?result;
????}

????public?static?byte[]?long2Bytes(int?id){
????????byte[]?arr?=?new?byte[8];
????????for?(int?i?=?0;?i?<?arr.length;?i++)?{
????????????arr[i]?=?(byte)?(long)?((id?>>?i?*?8)?&?0xff);
????????}
????????return?arr;
????}

????public?static?long?byte2Long(byte[]?arr){
????????long?result?=?0;
????????for?(int?i?=?0;?i?<?arr.length;?i++)?{
????????????long?s?=?(long)?((arr[i]?&?0xff)?<<?i?*?8);
????????????result?=?result?+?s;
????????}
????????return?result;
????}


????public?static?void?main(String[]?args)?{
????????byte[]?arr?=?demo01.int2Bytes(8143);
????????for?(int?in?:?arr
????????)?{
????????????System.out.print(in?+?",");
????????}
????????System.out.println();
????????System.out.println(demo01.byte2Int(arr));

????????byte[]?arr2?=?demo01.long2Bytes(8143);
????????for?(int?in?:?arr2
????????)?{
????????????System.out.print(in?+?",");
????????}
????????System.out.println();

????????System.out.println(demo01.byte2Long(arr2));
????}
}