java - 获取所有类参数及其名称？

Question

我正在寻找能够输入参数名称的用户，例如。 “sand”，然后我想知道哪个 block 引用了该名称。

引用代码:

public class Blocks implements ContentList {
public static Block air;
public static Block spawn;
public static Block deepwater;
public static Block water;
public static Block taintedWater;
public static Block tar;
public static Block stone;
public static Block craters;
public static Block charr;
public static Block sand;
public static Block darksand;
public static Block ice;
public static Block snow;
public static Block darksandTaintedWater;
public static Block holostone;
public static Block rocks;
}

我的尝试:

String targetBlock = ctx.args[2].toLowerCase();
                Block desiredBlock = Blocks.copperWall;
                for(Block block : Blocks.all()){
                    if (block.name == targetBlock){
                        desiredBlock = block;
                    }
                }

显然不行，因为Blocks.java没有.all()方法另外，Blocks.java 是自动生成的，我无法修改它或添加方法，有什么想法吗？

Answer 1

您应该使用反射来访问自动生成的 Blocks 文件的字段:

import java.lang.reflect.Field;

class Block {

    private String name;
    public Block(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}
class Blocks {

    public static Block wall = new Block("wall");
    public static Block corner = new Block("corner");
     ......
}

public class Main {
    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
        Field field = Blocks.class.getDeclaredField("wall"); // get the value from the args in real program
        Block b = (Block)field.get(null);
        System.out.println(b.getName());
    }
}

一些注意事项:

1. getDeclaredField如果您提供实际上不存在的数据字段的名称，则可以抛出 NoSuchFieldException
2. 我假设生成的 Block正如问题中出现的那样，实例是静态的，这就是我使用 field.get(null) 的原因而不是field.get(<something of type Blocks>)