public int[] findMaxAndMin(int[] array)
    {
        int[] res = new int[2];
        if (array == null)
        {
            return null;
        }
        else if (array.length == 1)
        {
            res[0] = array[0];
            res[1] = array[0];
            return res;
        }
        else
        {
            res[0] = array[0];
            res[1] = array[0];
            for(int i=1; i<array.length; i++)
            {
                res[0] = Math.max(res[0], array[i]);
                res[1] = Math.min(res[1], array[i]);
            }
        }

        return res;
    }

------解决方案--------------------
我编了一个，你看一下
package pak12;

public class Sui {

	public static void main(String[] args) {
		int[] shu={5,8,98,57,64,25,49,99,74,58};
		int zuida=max(shu);
		int zuixiao=min(shu);
		System.out.print("这个数组的最大值为："+zuida+"\n最小值为："+zuixiao);
		
	}
	public static int max(int[] zu){
		int result=0;
		result=zu[0];
		for(int i=1;i<zu.length;i++){
			if(result<=zu[i]){
				result=zu[i];
			}
		}
		return result;
	}
	public static int min(int[] zu){
		int result=0;
		result=zu[0];
		for(int i=1;i<zu.length;i++){
			if(result>=zu[i]){
				result=zu[i];
			}
		}
		return result;
	}

}