I am trying to figure out how to correctly bootstrap Weld (3.0.0) together with Jersey-Server (1.19.3) to establish a Rest Server with Java SE. I am not! talking about a JEE solution. The application server does a good job here.
I would like to have it standalone without all the libs I do not need.
My problem is that jersey server instantiates all the REST service classes in his own way and not using weld. Therefore #Inject does not work of course.
Does IoCInstantiatedComponentProvider help here ?
This is something Hammock provides, but if you want to just leverage the code that's fine. That's the beauty of open source - https://github.com/hammock-project/hammock/tree/master/rest-jersey/src/main/java/ws/ament/hammock/rest/jersey
Specifically, you'll need to instantiate the JerseyServlet and provide a ServletContextAttribute with the name jersey.config.servlet.internal.resourceConfig_JerseyServlet that points to a ResourceConfig object that either points to your Application object, or has all of the classes registered within it. We use a CDI extension to scrape these classes. I will say I'm using Jersey 2 not Jersey 1, I doubt this will work with Jersey 1 (which was made for CDI 1.0). Note that you need a servlet container still.
If you want to leverage Hammock, just add these dependencies to your project (I'm using Jetty below, but you can also use embedded tomcat or undertow):
<dependency>
<groupId>ws.ament.hammock</groupId>
<artifactId>rest-jersey</artifactId>
</dependency>
<dependency>
<groupId>ws.ament.hammock</groupId>
<artifactId>bootstrap-weld3</artifactId>
</dependency>
<dependency>
<groupId>ws.ament.hammock</groupId>
<artifactId>web-jetty</artifactId>
</dependency>
And then you just have to provide some annotated rest resources and a beans.xml
In an ideal world, you have your GWT app compiled to javascript, you serve it as static resource and you behind the scenes you have your back end code running on a JVM, and life goes well.
But that ideal world is called production during runtime.
However, during development time, when you would like to make use of the gwt code server...
You're GWT compile time dependencies are needed during runtime (sources + classes), for debugging and recompilation purposes of the GWT module.
At the same time, you may wish to have back-end supported by something like spring-boot 1.3.5.RELEASE.
In this case, spring boot, suffering multiple frequent releases, is at this point in time wanting to add as managed dependency, for example:
<hibernate-validator.version>5.2.4.Final</hibernate-validator.version>
Which, of course, is a very good thing. It is one of the many good features of spring, in fact.
Gwt, on the other hand, see link bellow,
http://www.gwtproject.org/doc/latest/DevGuideValidation.html
is still requiring you to use:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>4.1.0.Final</version>
<scope>runtime</scope>
</dependency>
Now, if you were to say: I do not care about productive development, just compile me something that works properly in production.
Then indeed, you can trivially solve the above problem by structuring your project in such manner:
ROOT
--- Backend-api
--- Backend-Impl
--- Gwt-Front-end
---- War or stand alone Spring jar module to glue it all together
Where you make the Gwt-Front end depend on the back-end APIs, for some RPC services and DTOs. The pom.xml dependencies you can for the most part manage only in your front-end module, independently of whichver dependencies you have in the back-end.
Ultimately, you make a war, or a spring boot runable jar, that carries your gwt code as static resources and carries your back-end code with all of its dependencies, namely Hirbernate validator latest version.
However, when you are trying to get a pom that works for development purposes, as far as i can see, you are stuck having to globally to manage the dependencies that are common between the back-end and the front-end layer in the ROOT pom.xml, and downgrading your dependencies to the version required by gwt.
That is, in the ideal world scenario.
You have your ROOT pom.xml simply declaring your modules and the order by which they get build. And you get your back-end-impl to have the power to state it wants to inherit dependencies from the spring-boot-starter pom.xml, etc...
In contrast to the ideal scenario, on the pom.xml configuration that actually helps you during the development time...
Well, you can have to revisit the Root pom.xml.
And you have to add in managed dependencies on this root pom.xml, so that for all those common conflicting dependencies between your GWT front-end and spring boot back-end, you always have to hammer the version of the GWT and put a downgrade in place.
This will ensure that when you do gwt:run, dev mode recompile, etc... you do not end up having the gwt compiler trying to javascript compile your Hibernate version 5, but instead the version that is indeed supported by GWT 4.1 final. Of course you might end up having a surprise in back-end code, one of these days by puting in place such a hack...
Does anybody have an idea of how to properly organize a multi module project where back-end and gwt based front-end are allowed to have conflicting depency requirements?
Ultimately, if the answer is no, I believe I will prefer to have network wastage and added communication delay, by having a pure stand-alone spring boot backend that integrates with a pure gwt stand alone jetty, where the back-end on this jetty does nothing more than dumbly kick the requests to the actual spring-boot backend. It is kind of pathetic to have gwt jetty back-end that gets called to do 1+1 by the UI and which forwards the computation to a second back-end running sprin boot that actual knows how to do the 1+1... but if this is the most productive way of working, ensuring that development is productive and the production will run without surprises, so be it.
Thanks for any feedback, and Ideally, I would like to see a multi-pom project that you can import as existing maven project into eclipse, and demonstrates how this can be achieved.
Figure out where the transitive dependency is that you want to exclude when compiling GWT code.
<dependency>
<groupId>spring-dependency-with-hibernate</groupId>
<artifactId>some-spring-boot-starter</artifactId>
<exclusions>
<exclusion>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
</exclusion>
</exclusions>
</dependency>
This way only the GWT provided hibernate version will be available at runtime.
Yes, what I wanted to do can in fact be done, though not trivially... not at all.
To setup a maven multi module pom that can be used productively in the sense that you can get code swapping both for back-end and front-end code without needing to choose either the gwt validator dependencies, or the springboot validator dependencies, essentially I organize my project as follows.
You have:
LEVEL 1: myproject-root
----- LEVEL 2: myproject-backend
---------- LEVEL 3: myproject-backend-api
---------- LEVEL 3: myproject-backend-impl
------ LEVEL 2: myproject-frontend
------ LEVEL 2: myproject-runner
-----------LEVEL 3: myproject-runner-jar
-----------LEVEL 3: myproject-runner-war
In myproject-root, you declare the submodules, naturally.
You do dependency management on some inocuous plugins such as surefire plugin. You control java source and target compile language. You do very little more than that. If you have some plugins that you can configure cross cutingly, you might as well put those in the plugin management.
In the myproject-backend, you essentially make it inherit into the dependency management the springboot depencies, by adding to your dependency management:
<dependencyManagement>
<dependencies>
<!-- Inherit dependencies from spring boot dependency management pom -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>${version.spring.boot}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
You declare the two submodules, and you're out.
You do not declare any cross cuting dependencies here. You only use the dependency management. The front-end component will be hiting the api submodule, and you do not want to be creating a dependency magnet in the backend pom, so here you are conservative as much as possible.
In the myproject-backend-api, you start by letting this submodule be a jar sub-module. Down the line, you will want to branch the api component further, by subdividing api-s by entrypoint nature.
To begin with the -api component will have apis needed for the communication between server and frontend, kind of like the typically seen "shared" in the documentation.
Here you are as careful as possible to have as little as possible in what regards to elements in the dependencies element. The front-end will be using these api's and you do not want your api package depending on any spring boot apis.
In the backend-impl, you write your actual business logic and you are free to depend on the full spring boot stack. The rule is, make sure no one ever points to this dependency magnet, especially, never let the gwt component even smell the existence of springboot libraries. Do not refer it ever.
In the myproject-frontend, you do not branch it into different sub-modules, as you might have done with the api component.
Here you make a monolitic component for gwt code so that you can more easily have the gwt maven plugin working for you doing your hot code recompilation.
In this component you depend on the myproject-api, as well as on any relevant gwt library, such as gwt-user, hibernate validator with the old version needed by gwt, etc...
The rule for the myproject-frontend is to declare every single dependency in the component as optional. You do not want to take any transitive depency on the component.
In production all you need is the myproject-frontend.jar/META-INF/resources/MyProjectModule.html...
And all such static resources that springboot will have to detect and serve.
While you are in development mode, however, what you want to do in this front end component is to:
(a) tune your gwt-plugin to not run the jetty server
<noServer>true</noServer>
The point being, if run this jetty server the only thing it would have in its classpath would be the front end code and the api, and definitely not the impl code.
And second, you do not want to use the gwt jetty, you either want to use the springboot tomcat or the springboot jetty. Much better to use the embedded containers of springboot with the appropriate websocket libraries and such.
(b) With springboot you want to server your static resources from the META-INF/resources/ or the public folder. I prefer the resources as it would be where you would normally put JSF components as well.
In any case, because the place static resources come from is special, you want to tune your gwt plugin to compile your java sources into the write folder.
<webappDirectory>${project.build.directory}/classes/META-INF/resources</webappDirectory>
So something like above.
Finally, and this was my main mistake, you do not run your code from where you write your front-end code.
That is wrong, because that forces your front-end code to need springboot depencies, which will cause you extreme pain due to conflicting libraries.
So for dodging this problem, you create the myproject-runner component, and if you want to be very detailed, you make that one a pom parent component so that you can fork your packaging into either jar or war.
I personally like the executable jar, much more to the point, than the war option. I will never want to deploy a sprinboot application in something like a heavy weight weblogic... but whatever rocks your boat.
In any case, the spring boot runner is your ultimate dependency magenet.
This component will depend on about every module you have and their transitive dependencies. But because you separate your runner component from the front-end code, and you make all the dependencies in the front-end code optinal...
Well, you essentially only bundle springboot, and the your gwt static resources.
While you are developing, what you do is .... once you know it ... simple.
(A) you start your spring boot jar application by triggering the main file. If you really want to deploy a war file, that-s your choice you can also build a war file and deploy it to a tomcat or whatever...
(b) you go to your frontend component, rirght click it, chooose run as Maven Build, and gwt:run.
The gwt run will start up the gwt code server, that will be completely blind to your backend code, the only thing it will see in front of its eyes is the code your have in the frontend component as well as all the gwt dependencies you've added in as optinal.
You can finally hot swap code in the back-end if you-re using springboot dev.
You can finally hot swap code in that monolitic frontend component, once you-ve started teh gwt plugin.
Conclusion, it-s possible, but its a hell of a mess.
Glad this problem is out of the way.
I believe I had similar problems and discovered the following while using Eclipse IDE, GWT Google Plugin, SpringBoot and Maven.
The recipe is not simple but it worked for my team.
GWT-dev and Jetty server doesn't work with SpringBoot.
You have to fix the classpath due to Jetty and gwt-dev hardcoded dependencies, only the dependencies gwt-dev and Jetty were built against will work.
I had to split the GWT UI project into two Maven artifacts.
One artifact was a WebApp capable of running only within Eclipse, with all SpringBoot libraries excluded from the classpath.
The other artifact was a deployable SpringBoot JAR with "war" maven packaging type and a WAR overlay of the Eclipse dedicated artifact, including only GWT specicic content.
I hope this helps
Just create dedicated maven profile for running GWT codeserver and add 'gwt-dev' dependency ONLY there
<profiles>
<profile>
<id>gwt-dev</id>
<dependencies>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-dev</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>${gwt.version}</version>
<executions>
<execution>
<id>run-codeserver</id>
<goals>
<goal>run-codeserver</goal>
</goals>
</execution>
</executions>
<configuration>
<sourceLevel>${java.version}</sourceLevel>
<module>kn.iopm.documentserver.IDocServer</module>
<extraJvmArgs>-Xmx1G -Xms512M -Xss1G -Dlog.root=${project.build.directory}/log
</extraJvmArgs>
<runTarget>index.html</runTarget>
<persistentunitcachedir>${project.build.directory}</persistentunitcachedir>
<webappDirectory>${project.build.outputDirectory}/public</webappDirectory>
<deploy>${project.build.directory}/gwt-deploy</deploy>
<codeServerWorkDir>${project.build.directory}/gwt</codeServerWorkDir>
<launcherDir>${project.build.outputDirectory}/static</launcherDir>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
I was able to define a Spring Boot project and include the following dependency in my pom:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
<version>1.0.0.RELEASE</version>
</dependency>
I then added the #EnableConfigServer annotation on my class. So far so good. I then created a bootstrap.yml file to point to my git repository. The application runs and picks up the configuration file I have defined in my repository. All seems to work well. To get to this point there was a lot of trial and error and digging around.
When I invoke http://localhost:8888/env I see two applicationConfig JSON objects appear. The first is from the configserver.yml file, which is embedded in the spring-cloud-config-server jar that contributes to the base spring context. The second is from my bootstrap.yml.
I am able to get access to the property files from my git repo as configured in my bootstrap.yml and am wondering how to override other properties that appear in the configserver.yml such as the server.port value. I apologize if this question was already asked. I am attempting to work with the spring-cloud-config-server jar as is and without modification and without pulling the code to rebuild.
The problem seemed to have been with the yaml files. I created an application.yml and reworked my bootstrap.yml, taking direction from the spring cloud samples.
I am using spring aop and have defined some aspects. Spring LTW is enabled on my tomcat.
In my application context:
<context:load-time-weaver/>
<aop:aspectj-autoproxy proxy-target-class="false"/>
Aspects are working fine too! but the target class is proxied! causing ClassCastException: can not convert $Proxy...
Note that I don't my target classes to be proxied!
If you are using AspectJ LTW you only need the tag
<context:load-time-weaver/>
in your Spring context file. So you can remove,
<aop:aspectj-autoproxy proxy-target-class="false"/>
If the target class is proxied is because LTW with AspectJ is not configured in a good way, for this reason is not AspectJ who is handling your advices, and is Spring who is doing that. For this reason you see proxy based target class.
Check this links,
http://static.springsource.org/spring/docs/3.2.2.RELEASE/spring-framework-reference/html/aop.html#aop-aj-ltw
http://static.springsource.org/spring/docs/3.2.2.RELEASE/spring-framework-reference/html/aop.html#aop-aj-ltw-environments
I want to migrate my EE application to OSGi. my application consist of business libraries, database JPA/Entities and a REST/WS interfaces. it also has a web client.
I start by prototyping the structure and making all the interfaces and bundles talking to each other in OSGi clean way. I want to use a clean specification as much as possible without any specific vendor or framework.
I am using bnd maven plugin to generate the manifest and the declarative services. I want to make a call from my rest resources to an OSGI service (on another bundle) using injection like so:
#Path("some-resources")
#Component
public class SomeResources{
private SomeService service = null;
#Reference
public void setController(SomeService service) { // <- this is never called
this.service = service;
}
#GET
#Produces(javax.ws.rs.core.MediaType.APPLICATION_XML)
public Object getSomeService() { // <- called
try {
service.process("Hello World"); // <- Error null object
}
...
}
Can i annotate the resource with bnd #Component and can the #Resource be injected?
everything works fine but the service is always null.
What should be the way to declare my bundle for BND to make it a web/wab package?
I use maven bundle:
<packaging>bundle</packaging>
...
<plugin>
<groupId>org.apache.felix</groupId>
<artifactId>maven-bundle-plugin</artifactId>
<version>2.3.7</version>
<extensions>true</extensions>
<dependencies>
<dependency>
<groupId>biz.aQute</groupId>
<artifactId>bndlib</artifactId>
<version>1.50.0</version>
</dependency>
</dependencies>
<configuration>
<supportedProjectTypes>
<supportedProjectType>ejb</supportedProjectType>
<supportedProjectType>war</supportedProjectType>
<supportedProjectType>wab</supportedProjectType>
<supportedProjectType>bundle</supportedProjectType>
<supportedProjectType>jar</supportedProjectType>
</supportedProjectTypes>
<instructions>
<_include>-osgi.bundle</_include>
</instructions>
</configuration>
<executions>
<execution>
<id>bundle-manifest</id>
<phase>process-classes</phase>
<goals>
<goal>manifest</goal>
</goals>
</execution>
<execution>
<id>bundle-install</id>
<phase>install</phase>
<goals>
<goal>install</goal>
</goals>
</execution>
</executions>
</plugin>
...
with bnd instructions
Web-ContextPath: my-root-http/rest/
Service-Component: *
OSGi has a part of specification called Remote Services. In very short it works in the way that you can register services with special service-properties and based on the properties technologies should pick up your service and create an endpoint from them. It is not only about REST but about any technology that handles remote calls. You may find information in the OSGi Core specification under the "Remote Services" chapter.
Well it is a specification but who implements it? Currently there are two bigger projects I tried. CXF DOSGi and Eclipse ECF. They offer several technologies that support Remote Services Specification. CXF especially upports Jax-RS based on it's implementation on both server and client side.
As I did not want to use spring specific solutions inside OSGi I did not use CXF on the end but created my own solution. It is based on Jersey and the Remote Services specification. When an OSGi Service is specified with the service.exported.interfaces=* and the service.exported.configs=org.everit.osgi.remote.jersey it will create a rest endpoint under the /rest/ path with HttpService. Your bundle does not have to be a wab it can be a simple bundle.
I must mention that if you expose your services via any of the Remote Services implementation you should take the Jax-RS annotations into an interface that is implemented by your original class and expose your service based on that interface.
Instead of #Resource and #Component annotations inside OSGi I suggest that you should use Blueprint (part of OSGi spec) that is amazingly similar to Spring. Currently Apache Aries and Gemini Blueprint implements it. With blueprint you can easily create beans and wire them to each other. If register your remote service in this way you can set any of the property with the help of blueprint (just like the property of a bean in the spring applicationcontext.xml).
You can find a sample application that I made at https://source.everit.biz/svn/everit-osgi/trunk/samples/jaxrs/ (user/passwd: guest/guest). There is a guide that explains how this samples can be started and developed at http://cookbook.everit.org
I hope the sample application helps you to get started with the Remote Services specification chapter.
To see how to use JPA and Injection (Blueprint) you should check the OSGi compendium specification for possibilities and find the implementation you like. I also made a sample project based on blueprint and hibernate-jpa that you can find as the sibling of the sample url I already provided.
Update
There is also a JAXRS extender implementation I made at https://github.com/everit-org/osgi-remote-jersey. See the README for documentation. It is different from the first in the way that this works based on whiteboard service properties.
I have experienced a similar problem with OSGi, Declarative Services and Jersey.
A resource can be annotated with #Component and #Reference annotations. This will instruct DS to create an instance of SomeResource class and to inject a valid reference into this instance when all dependecies (references) are satisfied.
The reason why your references are null is because JAX-RS implementation will create a new instance of SomeResource class for each web request. This instance of SomeResource class is not the same as the one created by DS.
I solved this problem by making reference variable static with Java static keyword:
private static SomeService service = null;
This ensured that a dependency reference is tied to a class object instead to an instance and then all instances could see the injected value.
This solution introduced a new problem. This reference must be cleared on unbind event (when service becomes unavailable) because it will not be destroyed when an instance is destroyed.
The problem would be solved when the #Path annotated type would be registered as a service itself. With DS you can than just inject other services. I faced this problem myself nearly a year ago. Thats why I wrote a small OSGi JAX-RS Connector which gives you exactly what I have described. Give it a try if you like: https://github.com/hstaudacher/osgi-jax-rs-connector