尝试加载派生类时出现java.lang.ClassNotFoundException

Question

我有两个不同的模块：MultiRealm和SurvivalRealm。MultiRealm提供了一个抽象类(LoadedRealm)，类SurvivalRealm (在模块SurvivalRealm中)对其进行了扩展。现在，MultiRealm尝试从jar加载SurvivalRealm类。但是在尝试加载时，我得到了以下错误：java.lang.NoClassDefFoundError: net/lightbluefoxlabs/dev/multirealm/core/multirealmcore/Realms/LoadedRealm，其中net/lightbluefoxlabs/dev/multirealm/core/multirealmcore/Realms/LoadedRealm是LoadedRealm类的正确位置。下面是Stacktrace：

[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.defineClass1(Native Method)
[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.defineClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.security.SecureClassLoader.defineClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader.defineClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader.access$100(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader$1.run(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader$1.run(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.security.AccessController.doPrivileged(Native Method)
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader.findClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.loadClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.loadClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.LoadedRealm.RealmFactory(LoadedRealm.java:54)
[23:03:52] [Thread-10/WARN]:    at net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.LoadedRealm.RealmFactory(LoadedRealm.java:20)
[23:03:52] [Thread-10/WARN]:    at net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.RealmManager.Initialize(RealmManager.java:22)
[23:03:52] [Thread-10/WARN]:    at net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.RealmManager.lambda$InitializeAsync$0(RealmManager.java:39)
[23:03:52] [Thread-10/WARN]:    at java.lang.Thread.run(Unknown Source)
[23:03:52] [Thread-10/WARN]: Caused by: java.lang.ClassNotFoundException: net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.LoadedRealm
[23:03:52] [Thread-10/WARN]:    at java.net.URLClassLoader.findClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.loadClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    at java.lang.ClassLoader.loadClass(Unknown Source)
[23:03:52] [Thread-10/WARN]:    ... 16 more

下面是SurvivalRealm类：

import net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.LoadedRealm;
import net.lightbluefoxlabs.dev.multirealm.core.multirealmcore.Realms.Worlds.RealmWorld;

public class SurvivalRealm extends LoadedRealm {

    public SurvivalRealm(String RealmPath) {
        super(RealmPath);
        Load();
    }

    @Override
    public void Load() {
        //LoadStuff
    }

    @Override
    public void Unload() {

    }
}

..。LoadedRealm中的这个静态函数尝试导入这个类：

public static LoadedRealm RealmFactory(String jarPath, String RealmPath)  throws RealmLoadException{
        try {
            File file = new File(jarPath);
            URLClassLoader c = new URLClassLoader(new URL[]{file.getAbsoluteFile().toURI().toURL()});
            Class<?> realmClass = c.loadClass(RealmClass);
            return (LoadedRealm)(realmClass.getDeclaredConstructor(String.class).newInstance(RealmPath));
        }catch (Exception e){
            throw new RealmLoadException(e);
        }
    }

以下是该结构的图片：

​

MultiRealm模块不会导入/“知道”(请原谅我的术语) SurvivalRealm模块，反之亦然。

我只是想实现一些不可能的事情吗？如果您需要.iml文件，只需问一声。任何帮助都将是非常感谢的，我已经尝试了一整天来解决这个问题。感谢您通读这期初学者的文章。

Answer 1

您应该尝试使用来自maven的pom文件来实现您的目标。多模块项目由引用一个或多个子模块的父POM定义。