Re: Created a class dynamically but could not use it to create typed objects

Fri, 23 May 2008 12:26:12 -0700 (PDT)
On May 16, 10:35 pm, Arne Vajh=F8j <> wrote:

You can reload a class by using a new classloader (and let the
old classloader and all objects of classes loaded by it go to GC).

 OK, I think my seconds thoughts were not baseless, as tomcat showed
to me generics don't appear to depend solely on compile time checks
and/or there definitely is a way around it
 I think there should be a way to load and handle generic classes at
run time. Tomcat does it
 This is what I did to see what was going on with tc classloaders and
generic classes:
 1) in I declared: CATALINA_OPTS=-verbose:class
 2) in /webapps/ROOT/META-INF/context.xml I set: reloadable="true"
 3) then I used some test classes to play with tc loaders and see live
how it would indeed reload changed and totally new class, even generic

package test.k00;
public class K00{
 public int i0;
 public long l0;

package test.k00;
public class K02{
 public int i2;
 public String aS2;

package test.k00;
import java.util.*;
// __
public class GenK00<T>{
 private String aS;
 public ArrayList<T> ALK00 = new ArrayList<T>();
// __
 public GenK00(String aS){
  this.aS = aS;

 4) Inside of index.jsp I included:

Loading Generic classes:<br/>
<%@page import="test.k00.*"%>

 GenK00<String> GK0 = new GenK00<String>("<String>");

 K00 k0 = new K00();
 k0.i0 = 0;
 k0.l0 = 0L;

 K00 k1 = new K00();
 k1.i0 = 1;
 k1.l0 = 1L;

 K00 k2 = new K00();
 k2.i0 = 2;
 k2.l0 = 2L;

 GenK00<K00> GK2 = new GenK00<K00>("K00");

 K02 J = new K02();
 J.i2 = 4748;
 J.aS2 = "aS2";

GK0.ALK00.size(): <%=GK0.ALK00.size()%>

GK0.ALK00: <%=GK0.ALK00%>

GK2.ALK00.size(): <%=GK2.ALK00.size()%>

GK2.ALK00: <%=GK2.ALK00%>

J: <%=J%>

 So all that I needs to be done is look into tc classloaders

 Am I missing anything here?


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