int[] oldArray = {1,2,3,4,5};
//new value
int newValue = 10;
//define the new array
int[] newArray = new int[oldArray.length + 1];
//copy values into new array
for(int i=0;i < oldArray.length;i++)
newArray[i] = oldArray[i];
//another solution is to use
//System.arraycopy(oldArray, 0, newArray, 0, oldArray.length);
//add new value to the new array
newArray[newArray.length-1] = newValue;
//copy the address to the old reference
//the old array values will be deleted by the Garbage Collector
oldArray = newArray;