动态加载罐上的AbstractMethodError

I am loading a plug-in dynamically. Both the plug-in and the software have been created by us.动态加载罐上的AbstractMethodError

I have an Interface lets call it Foo. There is also FooImpl that just implements that method But FooImpl is in the jar loaded dynamically public interface Foo { void write(..someArgument..) throws Exception; }

I have also a PluginLoader class here is the method
public 
Object loadPlugin(final String jarPath, final Class 
pluginInterface) { 
    try 
    { 
     final URI uri = new File(jarPath).toURI(); 
     final URL url = uri.toURL(); 

    final URLClassLoader ucl = new URLClassLoader(new URL[] { url }); 
    try 
    { 
     final Class<?> pluginClass = Class.forName("FooImpl", true, ucl); 

     // Verify if plugin implements plugin interface. 
     if (pluginClass.getInterfaces()[0].getName().equals(pluginInterface.getName())) 
     { 
      // Instantiate plugin. 
      return pluginClass.newInstance(); 

     } }//[...] </code></pre> 
This part is actually working well i think so because after doing some sysout on the pluginClass i notice:
the .getMethods() =
[public void FooImpl.write(..someArgumentType..) throws Exception, public abstract void some.package.Foo.write(..someArgumentType..) throws Exception]

the .getGenericInterfaces() = [interface some.package.Foo]

But when i try to call the method write here is what i get
java.lang.AbstractMethodError: FooImpl.write(..SomeArgumentType..;)V
I dont know why there is a ";" and a "V"

So basically i think that it try to call the interface method instead of the implemented one. So i'm wondering What is going on!

As usual, Thank you for your time and help

来源

2012-08-17 drgn

你是通过实例调用写入方法，即'（（Foo）instance）.write（??）'还是通过反射？ – MadProgrammer 2012-08-17 14:59:13

final PluginLoader loader = new PluginLoader（）; final Object loadedLayer = loader.loadPlugin（pathToPlugin，Foo.class）; this.plugin =（Foo）loadedLayer;我真的很抱歉，我没有使用stackoverFlow – drgn 2012-08-17 15:04:39

如果（pluginClass instanceof pluginInterface）） - 不应该这是你的接口检查？ – JamesB 2012-08-17 15:53:48

AbstractMethodError表明您的代码正在试图在运行时使用不同版本的类，而不是它最初构建的类。您需要确保在执行环境中，类路径中没有流行的接口实现版本。

来源

2012-08-17 15:31:56 JamesB

Humm，我加载插件的唯一时间是通过OP中描述的pluginLoader类。我也必须给我加载实现的jar的路径。但我会尝试验证classLoader加载的内容。 – drgn 2012-08-17 15:40:33

先生，你是我的英雄。我的班加载器确实有一个流氓实例。对于任何类似问题的人，只需在jvm选项中使用-verbose：class并调查该类的狂野流氓实例。感谢您的朋友 – drgn 2012-08-17 15:59:26

不客气。 – JamesB 2012-08-17 18:21:21

动态加载罐上的AbstractMethodError

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