动态改变数组的长度

1.通过反射

代码如下：

/**
*改变数组的长度

**/

private static Object changeArrLen(Object obj,int lenNew){

Class<?> objArrType = obj.getClass().getComponentType();

Object newArr = Array.newInstance(objArrType,lenNew);

int len = Array.getLength(obj);

System.arraycopy(obj,0,newArr,0,len>lenNew? lenNew:len);

return newArr;

}

/**
*打印数组

**/

private static void printArr(Object obj){

Class<?> objCls = obj.getClass();

if(!objCls.isArray()){

return;

}

for(int i = 0; i<Array.getLength(obj); i++){

System.out.print(Array.get(obj,i)+" ");

}

}

public static void main(String[] args){

int[] a = {1,2,4,3,5};

int[] newA = (int[])changeArrLen(a,6);

print(newA);

}