去除字符串兩端的空格 （模擬一個trim方法）

package com.yhqtv.java;

/*
 *去除字符串兩端的空格
 *
 *  @author  XMKJ  yhqtv.com Email:[e-mail]
 * @create 2020-04-30-15:48
 *
 */
public class Test {
    public static void main(String[] args) {
        String s = "  123 456    ";
        System.out.println(s);
        Test t = new Test();
        String abc = t.abc(s);
        System.out.println(abc);
   }

    public String abc(String s) {
        int a = 0;
        int b = 0;
        char k = ' ';
        char[] array = s.toCharArray();
        for (int i = 0; i < array.length; i++) {
            if (!(array[i] == k)) {
                a = i;
                break;
            }
        }
//        System.out.println(a);
        for (int length = array.length-1; length >= 0; length--) {
            if (!(array[length] == k)) {
                b = length+1;
                break;
            }
        }
//        System.out.println(b);
        String sub = s.substring(a, b);
        return sub;
    }
}