- 96/09/13 I got VerifyError in my applet.
- Your applet uses native methods. Native methods are not allowed in
applets. Some package such like JDBC-ODBC bridge uses native methods.
- 96/09/13 I got ClassNotFoundException.
- Have you made all proxy classes for classes that are transfered? Have
you copied the proxy classes on both client and server?
- 96/09/13 How do I use a Java compiler that
is other than javac.
- Let say you have Server.java and you want to make Server_Proxy.java
and Server_Skeleton.java with a compiler myjavac.
% myjavac Server.java
% ls
Server.java Server.class
% horbc -nocompile Server
% ls
Server.java Server.class Server_Proxy.java Server_Skeleton.java
% myjavac Server_Proxy.java Server_Skeleton.java
- You can write a small script to do the above procedure. Note that horbc
can take fully qualified class names as well as java source files.
- 96/09/13 I want to call a class remotely, but I don't have the souce
file of the class.
- The horbc compiler can generate proxy classes from classes as well
as java source files.
% horbc fully.qualified.class.name
- 96/09/13 Applet.getParameter() always returns null.
- Netscape Navigator version 3.0 has such a bug, when you use Japanese
encoding.
- 96/09/13 How do I start horb from inetd? How to write /etc/inetd.conf?
- You can't start a horb command from inetd.
- 96/09/13 How do I write port number in /etc/services?
- HORB does not refer to /etc/services.
- 96/09/13 When my client invites a server by _invite(), it returns
soon.
- _invite() is an asynchronous method and regardless of acceptance of
the invitation. If you need to know acceptance, call a client method from
the server to notify acceptance.
- 96/09/13 I got NetException(HostNotFoundException) for localhost
on Win95.
- You have to install TCP/IP protocol stack before running HORB.
- 96/09/13 I got HORBException:"Server not bound to port"
when I tried to register an object as a daemon server.
- When you write;
- HORBServer.registerObject(object, "className", "objectName",
port);
- port must be 0 or a HORBServer must be running at the port.
- 96/09/04 When I use persistent objects, Java crashes due to an illegal
access.
- I guess you recompiled classes under horb/classsrc/orb. The reason
is a bug of javac of Java JDK 1.0.x. Recompile horb/classsrc/orb/FileIOCI.java
without the -O option.
cd horb/classsrc/orb
javac -d ../../.. FileIOCI.java
- 96/09/04 When I run example/invitation2, it fails.
- I guess you recompiled classes under horb/classsrc/orb. The reason
is a bug of javac of Java JDK 1.0.x. Recompile horb/classsrc/orb/ObjectTable.java
without the -O option.
cd horb/classsrc/orb
javac -d ../../.. ObjectTable.java
- 96/09/13 Why can't I pass Vector, Hashtable, Date or Color to a
remote server?
- Because the current version cannot send private variables. Please use
Jason Raymond's Vector/Hashtable package. You can find horbUtil.zip at
the HORB repository.
- How do I set up my server written in HORB on our WWW server?
- See the Server
Setting for Applets section of the HORB flyer's guide.
- HORB is sometimes slow.
- See this.
I'm working on performance improvement.
- How do I use ACL from my program. My program does not use the horb
command.
AclStatus acl = new AclStatus();
acl.source = "client.acl";
AclStatus[] acls = new AclStatus[1];
acls[0] = acl;
HORBServer.startACL(acls, 0);
HORBServer hs = new HORBServer(8886, null, null);
- What are protocols?
- Special languages that are used in network. There so many protocols.
- How do I debug programs written in HORB?
- Use jdb or a debugger for Java.
- I want a logging or auditting facility.
- Future plans. Contributions are welcome.
- Why should I restart a new HORB@server or a new WWW browser when
I change a class file?
- Because the current Java interpreter does not support unloading of
classes.
- Server replication is needed, because my server is heavily loaded
and it has to serve many requests.
- Future plans. Contributions are welcome.
Use a multiprocessor machine. HORB utilizes the multiprocessors.
Or, use many server machines and give them one DNS hostname.
- Why doesn't a HORB server supply class files to a client? Why can't
my client send server classes to a HORB server?
- Such feature will be supported in future.
- I can specify the implementation class of an interface when I use
a configuration file. Why can't I specify the implementation class of an
interface to create remotely?
- For security reasons. If you can invoke an arbitrary class remotely,
it's too dangerous.
- How do I fly over our firewall?
- SOCKS is supported from JDK 1.0.2. Your standalone HORB client can
connect to outside over a firewall, if you have a SOCKS server on your
firewall machine. Set socksProxyHost and socksProxyPort of system
property (of Java, not HORB's). I don't know how to set the property.
- When I was recompiling the HORB package, I got errors compiling
ACL_Impl.java.
- No problem.
Makefile in the classsrc/orb directory won't work for me.
- That's right. It won't work for me.