flhs筆試題-回家上機實踐

這是最近參加的一個公司的筆試題，回家上機寫了下代碼，但願對有須要的小夥伴有用，簡單實現字符串和數組在指定位置的插入：

package org.flhs;

import com.google.common.base.Strings;

/**
* Created with IntelliJ IDEA.
* User: cutter.li
* Date: 14-3-7
* Time: 下午3:10
* To change this template use File | Settings | File Templates.
*/
public class FLHSTest {

    public static void main(String[] args) {

//        changePosition("iloveyou", 5);

       Object[] objArray= insertObjArrayInPosition(new Object[]{"a","b","hello"},new Object[]{"fuck","you"},3);

       printArray(objArray);

    }

    private static void printArray(Object[] objArray) {
        if(null!=objArray&&objArray.length>0)
        {
            for(Object obj:objArray)
            {
                System.out.print(obj+" , ");
            }
        }
    }

    //對指定位置先後的字符串的內容進行調換
    public static void changePosition(String str, int position) {
        String res = "";
        if (Strings.isNullOrEmpty(str)) {
            res = "改變的字符串爲空";
        } else {
            int len = str.length();

            if (position <= 0 || position >= len) {
                res = str;
            } else {
                String preTxt = str.substring(0, position);
                String remainTxt = str.substring(position, str.length());
                res = remainTxt + preTxt;

            }
        }
        System.out.println(res);
    }

//數組在指定位置的插入
    public static Object[] insertObjArrayInPosition(Object[] dest, Object[] source, int position) {
        if (null == dest) {
            return source;
        }

        if (null == source) {
            return dest;
        }
        int destSize = dest.length;
        int sourceSize = source.length;
        Object[] resObjArray = new Object[destSize + sourceSize];

        if (position <= 0) {
            System.arraycopy(source, 0,  resObjArray, 0, sourceSize);
            System.arraycopy(dest , 0, resObjArray, sourceSize, destSize);
        } else if (position > dest.length) {
            System.arraycopy(dest, 0,  resObjArray, 0, destSize);
            System.arraycopy(source, 0,  resObjArray, destSize, sourceSize);
        } else {
            System.arraycopy(dest, 0, resObjArray, 0, position);
            System.arraycopy(source, 0,  resObjArray, position, sourceSize);
            System.arraycopy(dest, position,  resObjArray, position+sourceSize, destSize - position);

        }
        return resObjArray;
    }

}