javasisst - 由于 "missing" 字段而未编译

Question

我有以下代码：

CtClass player = ClassPool.getDefault().get("org.spongepowered.api.entity.living.player.Player");
CtField toAdd = CtField.make("public java.lang.String nick = null;", player);
player.addField(toAdd);

后来我有这个：

e.getTargetEntity()/*this function returns a class that implements Player*/
Player.nick = e.getTargetEntity().getName();

如何编译这段代码？ eclipse 和 maven 都抛出编译异常，因为很明显，他们不知道 Player.nick 是一个字段这一事实。感谢任何帮助。

Answer 1

您必须使用反射来设置字段。

package hello;

import com.thoughtworks.xstream.XStream;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtField;

class Player {
}

class Main {
    public static void main(String[] args) throws Exception {
        CtClass player = ClassPool.getDefault().get("hello.Player");
        CtField toAdd = CtField.make("public java.lang.String nick = null;", player);
        player.addField(toAdd);

        Class patchedPlayer = player.toClass();
        Object o = patchedPlayer.newInstance();

        patchedPlayer.getField("nick").set(o, "hello, Player");

        String s = new XStream().toXML(o);
        System.out.println(s);
    }
}

将打印

<hello.Player>
  <nick>hello, Player</nick>
</hello.Player>

还要确保 e.getTargetEntity() returns 补丁 class 的对象，而不是原始对象。

javasisst - 由于 "missing" 字段而未编译

javasisst - Not compiling due to "missing" field

java

maven

javassist