字符串的排序，很简单

public class Temp {

public static void main(String[] args) {

String[] sortStr = new String[]{"1_C","3_A","2_B"}; 

   Arrays.sort(sortStr );//2，利用数组帮助类自动排序 

   System.out.println(Arrays.toString(sortStr));//3，输出 

}

}