I'm using embedded Felix in my application. Application can potentially deal with lot of plugins that exposes similar interface IFoo. There is default an implementation FooImpl Hopefully for most plugins default FooImpl can be used with specific configuration files.
I would like dynamically install and start the same bundle (with FooImpl) when new configuration file appears. I've reviewed already FileInstall but have no idea how to apply it there.
UPDATE: Deployment sequence. The jar containing FooImpl and IFoo is stable, but I need hot-deploy of new instances that are result of uploading new .cfg file to scope of FileInstall. So desired is very simple - user uploads .cfg, new service (instance of FooImpl) is appeared.
Using Factory Configurations would allow you to create different instances of FooImpl based on different configurations.
For example in Declarative Services you can create a component like
import org.apache.felix.scr.annotations.*;
import org.apache.sling.commons.osgi.PropertiesUtil;
#Component(metatype = true,
name = FooImpl.SERVICE_PID,
configurationFactory = true,
specVersion = "1.1",
policy = ConfigurationPolicy.REQUIRE)
public class FooImpl implements IFoo
{
//The PID can also be defined in interface
public static final String SERVICE_PID = "com.foo.factory";
private static final String DEFAULT_BAR = "yahoo";
#Property
private static final String PROP_BAR = "bar";
#Property(intValue = 0)
static final String PROP_RANKING = "ranking";
private ServiceRegistration reg;
#Activate
public void activate(BundleContext context, Map<String, ?> conf)
throws InvalidSyntaxException
{
Dictionary<String, Object> props = new Hashtable<String, Object>();
props.put("type", PropertiesUtil.toString(config.get(PROP_BAR), DEFAULT_BAR));
props.put(Constants.SERVICE_RANKING,
PropertiesUtil.toInteger(config.get(PROP_RANKING), 0));
reg = context.registerService(IFoo.class.getName(), this, props);
}
#Deactivate
private void deactivate()
{
if (reg != null)
{
reg.unregister();
}
}
}
Key points here being
You use a component of type configurationFactory
In the activate method you read the config and then based on that register a service
In deactivate you explicitly unregister the service
End users would then create config file with name <pid>-<some name>.cfg. Then DS would then activate the component.
Then you can create multiple instances by creating configuration (using File Install like) file with name <pid>-<some name>.cfg like com.foo.factory-type1.cfg
Refer to JdbcLoginModuleFactory and its associated config for one such example.
If you want to achieve the same via plain OSGi then you need to register a ManagedServiceFactory. Refer to JaasConfigFactory for one such example.
Key points here being
You register a ManagedServiceFactory instance with configuration PID as the service property
In the ManagedServiceFactory(String pid, Dictionary properties) callback register instances of FooImpl based on the config properties
Sounds like you want to only have one bundle with FooImpl installed but have it register multiple IFoo services, one for each configuration. Look at Declarative Services and use factory configurations with Config Admin to establish the multiple configurations for the DS component.
Related
Is it possible to have a Spring Boot properties file depend on two or more profiles? Something like application-profile1-profile2.properties?
Spring Boot does not support this out of the box. It only supports a single profile as described here.
However, it does provide enough flexibility to add your own property sources using EnvironmentPostProcessor.
Here is an example of how to implement this:
public class MultiProfileEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {
private final ResourceLoader resourceLoader = new DefaultResourceLoader();
#Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
String[] activeProfiles = environment.getActiveProfiles();
for (int i = 2; i <= activeProfiles.length; i++) {
Generator.combination(activeProfiles).simple(i)
.forEach(profileCombination -> {
String propertySourceName = String.join("-", profileCombination);
String location = "classpath:/application-" + propertySourceName + ".properties";
if (resourceLoader.getResource(location).exists()) {
try {
environment.getPropertySources().addFirst(new ResourcePropertySource(propertySourceName, location));
} catch (IOException e) {
throw new RuntimeException("could not add property source '" + propertySourceName + "'", e);
}
}
});
}
}
#Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE;
}
}
Couple of things to note:
This implementation only supports .properties files but can easily be extended to .yml files as well.
getActiveProfiles already returns the profiles in an order where the last one wins. This implementation relies on this order and builds the different file names leveraging this order. i.e. if active profiles are: profile1,profile2,profile3 then application-profile1-profile3.properties is supported but application-profile3-profile1.properties isn't, and application-profile1-profile3.properties will override properties defined in application-profile1.properties or application-profile3.properties.
This implementation uses a third party library com.github.dpaukov:combinatoricslib3 to create the different sets of profiles.
The property sources are added to the front of the property source list to override existing sources. But if you have custom property sources that should take precedence you need to modify this a bit to consider them in the order, i.e. by leveraging methods like Environment.addAfter.
Registering an EnvironmentPostProcessor is done using the spring.factories file.
There are 4 ways I know.
insert .yaml or .properties programmatically like Asi Bross Said. Use ResourceLoader or YamlPropertySourceLoader to insert.
Use .yaml. but it will be replace when you have a another spring project to dependent it.
Use properties instead of profiles. (For api project)
Use one #PropertySource to define properties file A.
Get the variables from properties file A and assign them to the parameters in another #PropertySource file path expression.
For example:
resources
/-application.properties <-- remove or empty,because it will be override by application project
/-moduleA
/-application.properties <-- Intellij can identify properties files started with application-
/-application-mysql-dev.properties
/-application-psql-dev.properties
/-application-psql-prod.properties
The content of resources/moduleA/application.properties :
moduleA.custom.profile1=mysql
moduleA.custom.profile2=dev
Content of Java Config file:
#SpringBootApplication
#PropertySources({
#PropertySource("/moduleA/application.properties"),
#PropertySource("/moduleA/application-${moduleA.custom.profile1}-${moduleA.custom.profile2}.properties"),
})
public class ModuleConfig {}
Use properties instead of profiles. (For application project)
resources
/-application.properties
/-application-mysql-dev.properties
/-application-psql-dev.properties
/-application-psql-prod.properties
The content of resources/application.properties :
moduleA.custom.profile1=mysql
moduleA.custom.profile2=dev
The content of SpringMvcApplication.java:
#SpringBootApplication
#PropertySource("/application-${moduleA.custom.profile1}-${moduleA.custom.profile2}.properties")
public class SpringMvcApplication {...}
My question is about what is best way to inhibit an endpoint that is automatically provided by Olingo?
I am playing with a simple app based on Spring boot and using Apache Olingo.On short, this is my servlet registration:
#Configuration
public class CxfServletUtil{
#Bean
public ServletRegistrationBean getODataServletRegistrationBean() {
ServletRegistrationBean odataServletRegistrationBean = new ServletRegistrationBean(new CXFNonSpringJaxrsServlet(), "/user.svc/*");
Map<String, String> initParameters = new HashMap<String, String>();
initParameters.put("javax.ws.rs.Application", "org.apache.olingo.odata2.core.rest.app.ODataApplication");
initParameters.put("org.apache.olingo.odata2.service.factory", "com.olingotest.core.CustomODataJPAServiceFactory");
odataServletRegistrationBean.setInitParameters(initParameters);
return odataServletRegistrationBean;
} ...
where my ODataJPAServiceFactory is
#Component
public class CustomODataJPAServiceFactory extends ODataJPAServiceFactory implements ApplicationContextAware {
private static ApplicationContext context;
private static final String PERSISTENCE_UNIT_NAME = "myPersistenceUnit";
private static final String ENTITY_MANAGER_FACTORY_ID = "entityManagerFactory";
#Override
public ODataJPAContext initializeODataJPAContext()
throws ODataJPARuntimeException {
ODataJPAContext oDataJPAContext = this.getODataJPAContext();
try {
EntityManagerFactory emf = (EntityManagerFactory) context.getBean(ENTITY_MANAGER_FACTORY_ID);
oDataJPAContext.setEntityManagerFactory(emf);
oDataJPAContext.setPersistenceUnitName(PERSISTENCE_UNIT_NAME);
return oDataJPAContext;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
...
My entity is quite simple ...
#Entity
public class User {
#Id
private String id;
#Basic
private String firstName;
#Basic
private String lastName;
....
Olingo is doing its job perfectly and it helps me with the generation of all the endpoints around CRUD operations for my entity.
My question is : how can I "inhibit" some of them? Let's say for example that I don't want to enable the delete my entity.
I could try to use a Filter - but this seems a bit harsh. Are there any other, better ways to solve my problem?
Thanks for the help.
As you have said, you could use a filter, but then you are really coupled with the URI schema used by Olingo. Also, things will become complicated when you have multiple, related entity sets (because you could navigate from one to the other, making the URIs more complex).
There are two things that you can do, depending on what you want to achieve:
If you want to have a fined grained control on what operations are allowed or not, you can create a wrapper for the ODataSingleProcesor and throw ODataExceptions where you want to disallow an operation. You can either always throw exceptions (i.e. completely disabling an operation type) or you can use the URI info parameters to obtain the target entity set and decide if you should throw an exception or call the standard single processor. I have used this approach to create a read-only OData service here (basically, I just created a ODAtaSingleProcessor which delegates some calls to the standard one + overridden a method in the service factory to wrap the standard single processor in my wrapper).
If you want to completely un-expose / ignore a given entity or some properties, then you can use a JPA-EDM mapping model end exclude the desired components. You can find an example of such a mapping here: github. The mapping model is just an XML file which maps the JPA entities / properties to EDM entity type / properties. In order for olingo to pick it up, you can pass the name of the file to the setJPAEdmMappingModel method of the ODataJPAContext in your initialize method.
The documentation states:
Developing auto-configuration and using conditions
If you work in a company that develops shared libraries, or if you work on an open-source or commercial library, you might want to develop your own auto-configuration. Auto-configuration classes can be bundled in external jars and still be picked-up by Spring Boot.
If I have annotations for everything else (even #AutoConfigureAfter or #AutoConfigureBefore annotations),
Why maintain a properties file to point to a class with an annotation?
Because we are not going to scan the world to figure out what auto-configuration classes exist in your project. For one, an auto-configuration is just a regular #Configuration class.
The way a Spring component is found is via explicit declaration or component scan but we need to know the list of auto-configuration classes way before we actually start the context.
When SpringBoot app is starting, it will not scan all the classes in jars, So SpringBoot starter should specify which classes are auto-configured. For example, in spring-boot-2.0.4.RELEASE, it initializes like this:
#SpringBootApplication
public class MyApplication {
public static void main(String[] args) {
//1. method run will call the construtor below
SpringApplication.run(MyApplication.class, args);
}
}
public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
this.resourceLoader = resourceLoader;
Assert.notNull(primarySources, "PrimarySources must not be null");
this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
this.webApplicationType = deduceWebApplicationType();
//2. find all the classes whose key is ApplicationContextInitializer in spring.factories and initialize them
setInitializers((Collection) getSpringFactoriesInstances(
ApplicationContextInitializer.class));
setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
this.mainApplicationClass = deduceMainApplicationClass();
}
...
private <T> Collection<T> getSpringFactoriesInstances(Class<T> type,
Class<?>[] parameterTypes, Object... args) {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
// Use names and ensure unique to protect against duplicates
Set<String> names = new LinkedHashSet<>(
//3. use current thread classcloader to load resources in the classpath
SpringFactoriesLoader.loadFactoryNames(type, classLoader));
List<T> instances = createSpringFactoriesInstances(type, parameterTypes,
classLoader, args, names);
AnnotationAwareOrderComparator.sort(instances);
return instances;
}
//SpringFactoriesLoader.java
public static List<String> loadFactoryNames(Class<?> factoryClass, #Nullable ClassLoader classLoader) {
String factoryClassName = factoryClass.getName();
// 3.1 first find the configuration file
return loadSpringFactories(classLoader).getOrDefault(factoryClassName, Collections.emptyList());
}
private static Map<String, List<String>> loadSpringFactories(#Nullable ClassLoader classLoader) {
...
try {
Enumeration<URL> urls = (classLoader != null ?
// public static final String FACTORIES_RESOURCE_LOCATION = "META-INF/spring.factories";
//4. spring.factories file is defined here
classLoader.getResources(FACTORIES_RESOURCE_LOCATION) :
ClassLoader.getSystemResources(FACTORIES_RESOURCE_LOCATION));
result = new LinkedMultiValueMap<>();
...
}
all the entries in spring.factories are loaded by below method -
org.springframework.boot.autoconfigure.ImportAutoConfigurationImportSelector#loadFactoryNames
protected Collection<String> loadFactoryNames(Class<?> source) {
return SpringFactoriesLoader.loadFactoryNames(source, getClass().getClassLoader());
}
SpringFactoriesLoader belongs to the spring-core library see below screen shot
Improve the startup performance by creating a static list of candidates at compilation time.Just scan a static 'spring.factories' file, avoiding scanning a large number of class files in jars. Similar to #indexed in springframework 5.0. --META-INF/spring.components.
Centralized configuration management, concise and compatible.
nI am developing a Spring MVC web app using Spring 3.2. We will deploy the web app to different customers. Each customer may use one of several implementations of a service interface.
It's possible that the customer may need to reset these values, so we can't just hard-wire the implementation into the application, it needs to be externally configurable.
We are already using customer-specific property files that for setting simple properties such as Strings, numbers etc, but I'm asking how to set a particular implementation of an interface.
E.g.,
class MyClass {
// this is straightforward
#Value("${customer.propertyInPropertyFile}")
private String customerSpecificString;
// how to set the correct implementation for each customer?
private ISomeService service;
}
If there are 4 implementations of ISomeService, we can't autowire, or explicitly set a bean, as this will then be set in the compiled code - and it needs to be configurable after the application is deployed ( it would be OK to restart the application though if need be)..
Does anyone know how to do this? Would this better be performed using Spring EL, or profiles?
Thanks!
So, as I wanted to used Java configuration, I used the following solution:
#Configuration
#Profile("prod")
#EnableAsync
public class ProductionConfig extends BaseConfig
// inject property value which identifies theimplementation to use
Value("${service.impl}")
private String serviceName;
#Bean()
public IRepository repository() {
IRepository rc = null;
if(StringUtils.isEmpty(serviceName)){
rc = new Impl1();
} else if ("sword-mets".equals(serviceName)){
rc = new Impl2();
} else {
rc = new Impl3();
}
log.info("Setting in repository implementation " + rc);
return rc;
}
So, this isn't quite as clean as the suggested reply using aliases - the Config class needs to know about all the possible implementation classes - but is simple and avoids having to use the XML config just for this bean.
Is it possible to run multiple instance of the same service in the osgi framework?
More specific, I need to start multiple instances of a service, but each instance should recieve different parameters. This is because the services have similar functionality. But instead of writing a service for every variation, I want to reuse one implementing class.
I've already found the registerService method in the framework api.
ServiceRegistration<?> registration = bundlecontext.registerService(
className, class, null);
however, i seem to create only one instance of each class. Is there a workaround for this?
preferably something like
ServiceRegistration<?> registration = bundlecontext.registerService(
className + "#" + (++counter), new classInstance(), null);
Note that using Declarative Services with the corresponding annotations makes this quite easy, here's an excerpt from the Apache Sling codebase (ConfiguredFeature.java):
#Component(
name = "org.apache.sling.featureflags.Feature",
metatype = true,
configurationFactory = true,
policy = ConfigurationPolicy.REQUIRE)
#Service
public class ConfiguredFeature implements Feature {
#Property(label = "Name", description = "Short name of this feature")
private static final String NAME = "name";
private String name;
#Activate
private void activate(final Map<String, Object> configuration) {
this.name = PropertiesUtil.toString(configuration.get(NAME), "");
}
...
}
Using configurationFactory = true and policy = ConfigurationPolicy.REQUIRE causes one instance of this service to be created for each corresponding OSGi configuration, which is a natural way of creating multiple instances.
You could create a ManagedServiceFactory. The factory can register a new service for each configuration set in Configuration Admin.
I have a simple example here which uses Felix DependencyManager to register the component: https://github.com/paulbakker/osgicourse/tree/master/greeterfactory/src/greeterfactory
You have the parameters slightly wrong, or at least misleading:
ServiceRegistration<?> registration = bundlecontext.registerService(
className, class, null);
The second parameter to registerService is an object, not a class. This is an object you instantiate yourself. You can create as many as you like, in whatever way you like, before passing them to OSGi.
However if you are doing this with externally-supplied configuration data, should look into Declarative Services and their ability to receive config from the OSGi Configuration Admin service.
UPDATE
Taking another look at your question, I see the counter that you tried to add to the class name. This is not required and in fact not permitted either. Just call registerService multiple times.