plumpmath / test-classloader

test classloader

Overview

There are 4 eclipse projects in this repository:

• fake-storm: plays the role of Storm
• user-topology: plays the role of User Topology
• testlib-storm: plays the role of Storm's dependency
• testlib-user: plays the role of User Topology's dependency, it is almost the same as testlib-storm, just the implementation of Man#hello is different.

Preparation

Before run the test, build the jar for user-topology and testlib-user, and put the two jars into /tmp folder, TopologyClassLoader will try to load the classes there.

So the jars in /tmp are:

$ ls /tmp/*.jar
/tmp/testlib-user.jar  /tmp/user-topology.jar

These two jars contains the User Topology's code and its dependencies.

Run the test

cd fake-storm
java -cp bin:../testlib-storm/bin/ 
     -Djava.system.class.loader=xumingmingv.classloader.TopologyClassLoader 
     xumingmingv.classloader.StormCore

-cp bin:../testlib-storm/bin/ specifies the Fake Storm Core Class and its dependencies.

Result

ClassLoader xumingmingv.classloader.StormCore
StormCore: StormCore classloader: sun.misc.Launcher$AppClassLoader@1ef6a746
StormCore: IPerson classloader: sun.misc.Launcher$AppClassLoader@1ef6a746
StormCore: Man classloader: sun.misc.Launcher$AppClassLoader@1ef6a746
StormCore: ISpout classloader: sun.misc.Launcher$AppClassLoader@1ef6a746
StormCore: UserSpout classloader: xumingmingv.classloader.TopologyClassLoader@67386000
StormCore: Man#hello: I am Man (testlib-storm)
UserSpout: UserSpout classloader: xumingmingv.classloader.TopologyClassLoader@67386000
UserSpout: IPerson classloader: xumingmingv.classloader.TopologyClassLoader@67386000
UserSpout: Man classloader: xumingmingv.classloader.TopologyClassLoader@67386000
UserSpout: ISpout classloader: sun.misc.Launcher$AppClassLoader@1ef6a746
UserSpout: Man#hello: I am Man (testlib-user)

We can see that the dependency is isolated from these two lines:

StormCore: Man#hello: I am Man (testlib-storm)
UserSpout: Man#hello: I am Man (testlib-user)