ClassNotFoundException em Applet

Algumas vezes, nos deparamos com o seguinte erro ao abrir um applet em um navegador:

load: class br.com.certificacao.TokenSignerApplet.class not found.
java.lang.ClassNotFoundException: br.com.certificacao.TokenSignerApplet.class
 at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: open HTTP connection failed:http://192.168.0.5:8082/certificaApp/br/com/certificacao/TokenSignerApplet/class.class
 at sun.plugin2.applet.Applet2ClassLoader.getBytes(Unknown Source)
 at sun.plugin2.applet.Applet2ClassLoader.access$000(Unknown Source)
 at sun.plugin2.applet.Applet2ClassLoader$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 ... 7 more
Exception: java.lang.ClassNotFoundException: br.com.certificacao.TokenSignerApplet.class
load: class br.com.certificacao.TokenSignerApplet.class not found.
java.lang.ClassNotFoundException: br.com.certificacao.TokenSignerApplet.class
 at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: open HTTP connection failed:http://192.168.0.5:8082/certificaApp/br/com/certificacao/TokenSignerApplet/class.class
 at sun.plugin2.applet.Applet2ClassLoader.getBytes(Unknown Source)
 at sun.plugin2.applet.Applet2ClassLoader.access$000(Unknown Source)
 at sun.plugin2.applet.Applet2ClassLoader$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 ... 7 more
Exception: java.lang.ClassNotFoundException: br.com.certificacao.TokenSignerApplet.class

No meu caso, sofri com isso usando o Internet Explorer. Se isso acontecer com você, tente as seguintes situações:

1. Utilizar outro browser ( ou outra versão do seu browser);
   
2. Tentar desabilitar o uso de proxy (pode ser que o proxy esteja barrando alguma coisa relacionada ao uso de applets, neste caso, você terá que solicitar ao gerente da rede um ajuste no proxy);
   
3. Trocar a ordem dos parâmetros java_code e java_archive , deixando o java_archive antes.
   

   <param name="java_archive" value="TokenSignerApplet.jar, bcprov-jdk14-138.jar, iText-2.0.8.jar">
   
   <param name="java_code" value="br.com.certificacao.TokenSignerApplet.class">
   
   <param name="java_codebase" value="<%="http://"+request.getServerName()+":"+request.getServerPort()+request.getContextPath()%>">