我正在制作一个名为Minecraft with Bukkit API的游戏插件.

我有一个名为Reinforcements的数据库表,其中包含以下字段：x integer,y integer,z integer.加固块是受保护的块,意味着它不能被破坏.

我正在使用EntityExplodeEvent来检查TNT爆炸.

我遍历event.blocklist()并将每个块与Reinforcements表中的条目进行比较.如果存在,则使用event.blocklist().remove来防止在爆炸中对Reinforced块的损坏.

我可以通过获取每个坐标(x,y,z)的最小和最大,然后检查这两个数字之间的数据库行来实现.这个问题是它是一个立方体.我应该检查球体.我该怎么做呢？

这是我到目前为止所得到的,请注意：我知道这不是一个select语句的问题,因为我可以将返回的行与event.blocklist()进行比较,但我需要知道如何在我执行此操作时稍后再去做一个更新声明.

我之所以需要知道如何检查球体中的行是因为最终我会在Reinforcements表中添加一个额外的字段,称为“耐久性整数”,它会在每次爆炸后减少.由于爆炸是一个球体,因此更新查询应该只更新该球体中的行,而不是多维数据集.

任何人？

谢谢

当前的MySQL查询

"SELECT X, Y, Z FROM REINFORCEMENTS WHERE DURABILITY >= 1 " +

"AND x<=? AND x>=? AND y<=? AND y>=? AND z<=? AND z>=? AND world=?");

完整的代码

@EventHandler

public void checkForExplosion(EntityExplodeEvent event){

if(event.isCancelled()){

return;

}

//Store blocks that are inside explosion's blast radius

List blastRadiusBlocks = event.blockList();

//If explosion occurs in mid air it returns 0 so no need to go any

//further since there are no blocks inside the explosions radius

if(blastRadiusBlocks.size() < 1){

return;

}

HashMap affectedBlocks = new HashMap();

//Initialize min & max X,Y,Z coordinates

int smallestX = blastRadiusBlocks.get(0).getX();

int largestX = smallestX;

int smallestY = blastRadiusBlocks.get(0).getY();

int largestY = smallestY;

int smallestZ = blastRadiusBlocks.get(0).getZ();

int largestZ = smallestZ;

//World Name

String worldName = blastRadiusBlocks.get(0).getWorld().getName();

World world = this.myPlugin.getServer().getWorld(worldName);

//Find min & max X,Y,Z coordinates

for(int i = 0; i < blastRadiusBlocks.size(); i++){

Block block = blastRadiusBlocks.get(i);

int blockX = block.getX();

int blockY = block.getY();

int blockZ = block.getZ();

if(blockX < smallestX){

smallestX = blockX;

}

if(blockX > largestX){

largestX = blockX;

}

if(blockY < smallestY){

smallestY = blockY;

}

if(blockY > largestY){

largestY = blockY;

}

if(blockZ < smallestZ){

smallestZ = blockZ;

}

if(blockZ > largestZ){

largestZ = blockZ;

}

//Instantiate Coordinate class passing in parameters

Coordinate coordinate = new Coordinate(world, blockX, blockY, blockZ);

//Put a new entry of type Coordinate as key and type Block as value

affectedBlocks.put(coordinate, block);

}

try {

//Query database for any reinforced blocks that may be in the blast radius

//Reinforced blocks should have a durability > 0 (aka >= 1)

PreparedStatement ask = this.conn.prepareStatement(

"SELECT X, Y, Z FROM REINFORCEMENTS WHERE DURABILITY >= 1 " +

"AND x<=? AND x>=? AND y<=? AND y>=? AND z<=? AND z>=? AND world=?");

ask.setInt(1, largestX);

ask.setInt(2, smallestX);

ask.setInt(3, largestY);

ask.setInt(4, smallestY);

ask.setInt(5, largestZ);

ask.setInt(6, smallestZ);

ask.setString(7, worldName);

ask.execute();

ResultSet result = ask.getResultSet();

//If there was some found, loop through each one

while(result.next()){

//Get X,Y,Z coords of reinforced block

int x = result.getInt(1);

int y = result.getInt(2);

int z = result.getInt(3);

//Pass in x, y, z of reinforced block into affectedBlocks HashMap to instantiate a Block

Block protectedBlock = affectedBlocks.get(new Coordinate(world, x, y, z));

//Then remove the protectedBlock from explosion list

event.blockList().remove(protectedBlock);

}

result.close();

ask.close();

} catch (SQLException e) {

System.err.println("Citadel - Select Reinforcement can't keep up (possibly too many explosions):\n" + e);

}

}

解决方法:

SELECT X, Y, Z FROM REINFORCEMENTS

WHERE DURABILITY >= 1

AND world=?

AND (POW((X-?),2)+POW((Y-?),2)+POW((Z-?),2))

参数为woldID,爆炸的X,Y,Z和爆炸半径

标签：java,mysql,minecraft

来源： https://codeday.me/bug/20190626/1291414.html