Java经典安全数组实现，java经典数组,final class

Java经典安全数组实现，java经典数组,final class

final class DataSources {    private int size;    private DataSource[] data = new DataSource[4];    final int size(){        return size;    }    final DataSource get(int idx){        if (idx >= size)            throw new IndexOutOfBoundsException("Index: "+idx+", Size: "+size);        return data[idx];    }    final void add(DataSource table){        if(size >= data.length ){            DataSource[] dataNew = new DataSource[size << 1];            System.arraycopy(data, 0, dataNew, 0, size);            data = dataNew;        }        data[size++] = table;    }}