ÄãÄÜͨ¹ýÏÂÃæµÄ3µÀjavaÃæÊÔÌâÂð?

1.java static inner class ºÍ non-static inner classµÄÇø±ð?
2.Çëд³öÒ»¸ösingletonģʽµÄclass.
ÄãÈç¹ûд³öÏÂÃæµÄ2ÖÖÑùʽ,ÎÒ»áÎÊÄã:ÇëÎÊÄãÈçºÎÔÚͬһ¸öjvmÖв¢ÇÒÔÚͬһ¸öclassLoaderÖеõ½ËüµÄ¶à¸öʵÀý?(Çë²»ÒªÆæ¹Ö)
ÑùÁÐ1:
public class Singleton {  
 private final static Singleton instance=new Singleton();
 private Singleton(){} 
 public static Singleton newInstance(){  
  return instance;  
 } 
}
ÑùÁÐ2:
public class Singleton { 
 private static volatile int instanceCounter=0; 
 private Singleton(){
  if(instanceCounter>0)
   throw new RuntimeException("can't create multi instances!");
  instanceCounter++;
 }
 
 private final static Singleton instance=new Singleton();
 public static Singleton newInstance(){  
  return instance;  
 }
}
3.java µÄexception ·Öchecked,unchecked.ÏñRuntimeException,Error¶¼²»ÓÃÏÔʽtry-catch,Ö±½Ó¿ÉÒÔthrow,
µ«ÊÇÒ»°ãµÄexceptionÊDZØÐëcatchµÄ:
throw new Exception("..."),Èç¹ûÕâ¾ä²»ÔÚtry-catchÌåÄÚ,»òÕß·½·¨µÄÉùÃ÷ûÓÐthrows,ÄÇô±àÒëÊÇͨ²»¹ýµÄ.
ok,Çë¿´ÈçϵĴúÂë:
public class TestClass { 
 
 public void  testMethod()/*ÕâÀïûÓÐthrows Ŷ!*/{  
          ......
           throw new Exception("force throw the exception...");
          ......
 }
}
ºÜÃ÷ÏÔÉÏÃæµÄ·½·¨Èç¹ûÕâÑùµÄ»°ÊÇͨ²»¹ý±àÒëµÄ,µ«ÊÇÈç¹û·ÇµÃÒªÄãÔÚtestMethodÌåÖÐÔÚÔËÐÐʱthrowÒ»¸öºÜÒ»°ãµÄException,ÇëÎÊÄãÓа취Âð? 
Õâ3µÀÌâ¿É²»ÊÇsun³öµÄ¿¼ÌâŶ!²»ÐÅÄãËÑËÑ......