Java Pair

Sometimes during the design of an interface I want to return two objects instead of one for a certain method. Yes, this might be bad practice. But sometimes I just need it. In good old c++ with stl, there was a solution for this by using pairs. In java, there's no such thing as pairs and a Map is too bulky. So here's the Java 5 Pair implementation:

public final class Pair {
public final A first;
public final B second;

public Pair(A first, B second) {
this.first = first;
this.second = second;
}

public A getFirst() {
return first;
}

public B getSecond() {
return second;
}
}

Sun Application Server as a server

The following page http://docs.sun.com/source/819-0076/auto-restart.html#wp1027849 gives information about how to startup the sun application server as a windows service.

Spring and Sun Application server 8.2

I'm currently working on a project that must run on a Sun Application Server version 8.2. While setting up the webflow and template jsp pages I got the following exception:

java.lang.IllegalStateException: Unexpected reflection exception - java.security.AccessControlException: access denied (java.lang.reflect.ReflectPermission suppressAccessChecks)
at org.springframework.util.ReflectionUtils.handleReflectionException(ReflectionUtils.java:136)
at org.springframework.core.ReflectiveVisitorHelper.invokeVisit(ReflectiveVisitorHelper.java:100)
at org.springframework.core.style.DefaultValueStyler.style(DefaultValueStyler.java:56)
at org.springframework.core.style.StylerUtils.style(StylerUtils.java:47)
at org.springframework.webflow.engine.TransitionableState.getRequiredTransition(TransitionableState.java:80)
at org.springframework.webflow.engine.TransitionableState.onEvent(TransitionableState.java:107)
at org.springframework.webflow.engine.Flow.onEvent(Flow.java:534)

Ouch! So, I tested the same ear on a JBoss instance, and that worked without a problem. After doing some research I figured out that the sun application server is starting up with the following system property:

-Djava.security.policy=${com.sun.aas.instanceRoot}/config/server.policy

And yes, that is causing the AccessControlException, because the spring framework isn't allowed to do reflection. So how can we solve this?

Solution one: In the domain.xml file put the following line in comments

-Djava.security.policy=${com.sun.aas.instanceRoot}/config/server.policy

Solution two: Start editing the server.policy file for the domain. This is the most secure solution, but as solution one is much easier, I would pick that one. Also because the customer will be responsible for his own server in production.

Sun Application Server 8.2 on ubuntu

By default it's not possible to install the sun application server version 8.2 on ubuntu or debian. I always got the following error:

./sjsas_pe-8_2-linux.bin: error while loading shared libraries: libstdc++-libc6.2-2.so.3: cannot open shared object file: No such file or directory

But the following link gave me the solution: http://www.javafree.org/javabb/viewtopic.jbb?t=853068

Procedure:

- Install the package "libstdc++2.10-glibc2.2". This package is by default available in the sources, so you can use synaptic or any other package manager
- Download the sun application server from: http://java.sun.com/j2ee/1.4/download.html
- chmod u+x sjsas_pe-8_2-linux.bin
- ./sjsas_pe-8_2-linux.bin
- Follow the on screen instructions.