类A:类A并没有继承类B protected static Log log =
LogFactory.getLog(Scope.class.getName());这个类A对类B的引用。我不明白的是,类B的那些函数都没有实现的代码,类A引用后,引用类B的方法怎么会执行相关的功能呀!类B的函数并没有功能实现代码呀!类B:
package org.apache.commons.logging;public abstract class LogFactory { // Fields
static LogFactory logFactory; // Constructors
protected LogFactory() { } // Methods
public abstract Object getAttribute(String string);
public abstract String[] getAttributeNames();
public abstract Log getInstance(Class _class) throws LogConfigurationException;
public abstract Log getInstance(String string) throws LogConfigurationException;
public abstract void release();
public abstract void removeAttribute(String string);
public abstract void setAttribute(String string, Object object);
public static LogFactory getFactory() throws LogConfigurationException { return null;}
public static Log getLog(Class _class) throws LogConfigurationException { return null;}
public static Log getLog(String string) throws LogConfigurationException { return null;}
public static void release(ClassLoader classLoader) { }
public static void releaseAll() { }
}
LogFactory.getLog(Scope.class.getName());这个类A对类B的引用。我不明白的是,类B的那些函数都没有实现的代码,类A引用后,引用类B的方法怎么会执行相关的功能呀!类B的函数并没有功能实现代码呀!类B:
package org.apache.commons.logging;public abstract class LogFactory { // Fields
static LogFactory logFactory; // Constructors
protected LogFactory() { } // Methods
public abstract Object getAttribute(String string);
public abstract String[] getAttributeNames();
public abstract Log getInstance(Class _class) throws LogConfigurationException;
public abstract Log getInstance(String string) throws LogConfigurationException;
public abstract void release();
public abstract void removeAttribute(String string);
public abstract void setAttribute(String string, Object object);
public static LogFactory getFactory() throws LogConfigurationException { return null;}
public static Log getLog(Class _class) throws LogConfigurationException { return null;}
public static Log getLog(String string) throws LogConfigurationException { return null;}
public static void release(ClassLoader classLoader) { }
public static void releaseAll() { }
}
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