Garbage Collector program does not run

[tushar panda]

when i run the code below given in K&B book , to find memory deallocated it runs perfectly and gives output

  
  import java.util.Date;
   public class CheckGC { 
      public static void main(String [] args) {
         Runtime rt = Runtime.getRuntime();
         System.out.println("Total JVM memory: "+ rt.totalMemory());
         System.out.println("Before Memory = "+ rt.freeMemory());
         Date d = null;
         for(int i = 0;i<10000;i++) {
            d = new Date();
           d = null;
        }
        System.out.println("After Memory = "+ rt.freeMemory());
        rt.gc();   
        System.out.println("After GC Memory = "+ rt.freeMemory());
     }
  }

 

but when i write a similar code , given below

  
 import java.util.Date ;
 public class garbage{
 public static void main(String[]args){
   Runtime rt = Runtime.getRuntime();
   System.out.println("total memory before any work :"+rt.totalMemory());
   System.out.println("free memory before any work :"+rt.freeMemory());

Date d = null;
for(int i=0;i<1000;i++)
{ d  = new Date();
  d = null ;
}

System.out.println("free memory after allocating memory :"+rt.freeMemory());

rt.gc();

System.out.println("free memory after garbage collector :"+rt.freeMemory());

}

}
  

i get a error

    
Exception in thread "main" java.lang.NoClassDefFoundError: garbage/java

why so ? only changing class name gives this error ? is CheckGC a predefined class ?

[Henry Wong]

why so ? only changing class name gives this error ? is CheckGC a predefined class ?

Question. When you changed the name of the class, did you also change the name of the source file, and recompile?

Henry

[Henry Wong]

Exception in thread "main" java.lang.NoClassDefFoundError: garbage/java

Oh.... did you happen to run it as....

> java garbage.java

instead of ...

> java garbage

Henry