Question

所以，我有代码找到一个对象最接近0,0的空点。它落入无限循环，因为ArrayList就像一个指针列表。

        private static voxel findEmptySpot(){

    ArrayList<voxel> open = new ArrayList<voxel>();
    ArrayList<voxel> closed = new ArrayList<voxel>();

    String island = null;

    open.add(new voxel(0,0));

    do{

        voxel pos = new voxel();

        //Check for place closest to origin
        int d = -1;

        for(voxel test: closed){
            SkyCraft.getInstance().getLogger().info("Closed: "+test.x+","+test.y);
        }

        for(voxel test: open){
            int s = abs(test.x)+abs(test.y);
            SkyCraft.getInstance().getLogger().info("Position "+test.x+", "+test.y+" distance "+s+" best "+d);
            if(d==-1){
                d = s;
                pos.x = test.x;
                pos.y = test.y;
            }
            if(s<d){
                d = s;
                pos.x = test.x;
                pos.y = test.y;
            }
        }

        SkyCraft.getInstance().getLogger().info("Closest found; testing.");

        Island i = SkyCraft.db().getIsland(pos.x+";"+pos.y);

        if(i.owner!=null){
            if(i.owner.equals("")){
                return pos;
            }else{
                voxel x1 = new voxel(pos.x+1, pos.y);
                voxel x2 = new voxel(pos.x-1, pos.y);
                voxel y1 = new voxel(pos.x, pos.y+1);
                voxel y2 = new voxel(pos.x, pos.y-1);
                if(!closed.contains(new voxel(pos.x+1, pos.y))){
                    if(!open.contains(new voxel(pos.x+1, pos.y))){
                        open.add(new voxel(pos.x+1, pos.y));
                    }
                }
                if(!closed.contains(new voxel(pos.x-1, pos.y))){
                    if(!open.contains(new voxel(pos.x-1, pos.y))){
                        open.add(new voxel(pos.x-1, pos.y));
                    }
                }
                if(!closed.contains(new voxel(pos.x, pos.y+1))){
                    if(!open.contains(new voxel(pos.x, pos.y+1))){
                        open.add(new voxel(pos.x, pos.y+1));
                    }
                }
                if(!closed.contains(new voxel(pos.x, pos.y-1))){
                    if(!open.contains(new voxel(pos.x, pos.y-1))){
                        open.add(new voxel(pos.x, pos.y-1));
                    }
                }
                open.remove(pos);
                closed.add(pos);

            }
        }else{
            return pos;
        }

    }while(true);


}

当列表的值关闭打印时，这些值都等于当时变量pos的值。它就像是来自C ++的指针列表。如何让ArrayList实际包含对象本身，而不是对象的引用？

Answer 1

我刚使用了＆＃34; new＆＃34;函数创建变量的实例，然后将ant分配给ArrayList。谢谢@William Price的帮助。

ArrayList内容作为指针

1 个答案: