实例化使用反射实现特定接口的Java类 [英] Instantiate Java classes which implements specific Interface using reflection

问题描述

我是反思的新人。我已经看过一些问题和教程。

让我们假设我有一个界面，它由3个类A，B，C p>

  public interface MyInterface {
 doJob（）; 
  
 
 
 
} 
 
 
 
调用每个类
 类<？> processor = Class.forName（com.foo.A）; 
 Object myclass = processor.newInstance（）; 
  
不能创建一个对象，我不能将整个过程限制为特定类型。 
我只想调用 MyInterface 类型类。 
 
 
 
如果我通过com.foo.A它应该创建一个类对象，com.foo.B应该做B类Object，但如果我通过一些com.foo。 
 
 
 
如何实现这个？
解决方案
尝试
  MyInterface newInstance（String className）throws ClassNotFoundException，InstantiationException，IllegalAccessException { 
 Class<？> cls = Class.forName（className）; 
 if（！MyInterface.class.isAssignableFrom（cls））{
 throw new IllegalArgumentException（）; 
} 
 return（MyInterface）cls.newInstance（）; 
} 
  
 
I am new to Reflection. I have seen some of the questions and tutorials.

Let's assume I have one interface which's implemented by 3 classes A,B,C
public interface MyInterface {
doJob();
} 

Now using reflection I want to invoke each class
Class<?> processor = Class.forName("com.foo.A");
Object myclass = processor.newInstance();
Rather than creating an Object, can't I restrict the whole process to specific type.
I want to invoke only MyInterface type classes. 

If I pass com.foo.A it should create A class object, com.foo.B should do B class Object, but if I pass some com.foo.D who exists but still doesn't implement MyInterface shouldn't be invoked.

How can I achieve this?
解决方案
try
MyInterface newInstance(String className) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
    Class<?> cls = Class.forName(className);
    if (!MyInterface.class.isAssignableFrom(cls)) {
        throw new IllegalArgumentException();
    }
    return (MyInterface) cls.newInstance();
}


                        
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