I am trying to create a pollable message source and I have tried to do that by extending MessageProducerSupport, however I was able to see the message from receive method only once and was not successful in making it pollable. (The receive method is not getting called based on my polling schedule.)
My code snippet is as below:
#Component
public class MyAdapter extends MessageProducerSupport {
#Override
protected void doStart() {
receive();
}
public void receive() {
System.out.println("polled at : "+ new Date());
sendMessage(MessageBuilder.withPayload("Hello WOrld! "+ new Date()).build());
}
}
And my applicationContext is as below:
<context:component-scan base-package="com.mypackage" />
<context:annotation-config />
<bean id="pollerTaskExecutor" class="org.springframework.core.task.SyncTaskExecutor"/>
<int:inbound-channel-adapter ref="myAdapter" channel="output">
<int:poller task-executor="pollerTaskExecutor">
<int:interval-trigger interval="3000" fixed-rate="true" time-unit="MILLISECONDS"/>
</int:poller>
</int:inbound-channel-adapter>
I would like to know what am I missing to make this message source pollable.
You are right: the pollable message source is based . erm... on org.springframework.integration.core.MessageSource.
So, to make it working you just should move your MessageProducerSupport code to the AbstractMessageSource implementation.
See more info in the Reference Manual.
Related
From what I've read of the Spring #ContextConfiguration annotation, it's possible to load multiple XML context files, or multiple JavaConfig classes. What I need is to load from one XML context file and one class. All the examples I've seen either load all XML, or all classes, but not both.
I'm trying to do this because I want my test class, which is just there to verify expected Spring wiring, to load my default applicationContext.xml file (presently just a copy stored in "src/test/resources, and trying to figure out how to directly specify the default one) along with a JavaConfig class that specifies some JNDI resources that need to be available. For the purposes of my test, I only need to set those JNDI resources to dummy strings, but I'd really like to specify them in an inline static class instead of an external XML file, because my tests are going to have to verify that some settings are equal to those dummy strings, and it's more maintainable if both the values and the checks are in the same file.
What I have so far, and what I've tried, can be illustrated with this:
#RunWith(SpringRunner.class)
#ContextConfiguration(value = {"/testApplicationContext.xml", "/testResources.xml"})
//#ContextHierarchy({
// #ContextConfiguration("/testApplicationContext.xml"),
// #ContextConfiguration(classes = SpringWiringTest.Config.class)
//})
#TestPropertySource(properties = { "env = tomcat", "doNotifications = false" })
public class SpringWiringTest {
And this at the end of the class:
#Configuration
public static class Config {
#Bean public String uslDatasourcesList() { return "abc"; }
#Bean public String atgDatasourcesList() { return "abc"; }
#Bean public String uslTableNamePrefixsList() { return "abc"; }
#Bean public String atgTableNamePrefixsList() { return "abc"; }
#Bean public String doNotifications() { return "false"; }
#Bean public DataSource abc() { return new DriverManagerDataSource(); }
}
If I comment out the first #ContextConfiguration and comment back in the #ContextHierarchy block, I get an error like this:
Error creating bean with name 'uslDatasourcesList': Invocation of init
method failed; nested exception is
javax.naming.NoInitialContextException: Need to specify class name in
environment or system property, or as an applet parameter, or in an
application resource file: java.naming.factory.initial
Update:
Using the guideline of picking either JavaConfig or XML as the "entry point" to configuration, here are some modified excerpts that show what I'm trying:
#RunWith(SpringRunner.class)
#ContextConfiguration
//#ContextConfiguration(value = {"file:src/main/webapp/WEB-INF/applicationContext.xml", "/testResources.xml"})
#TestPropertySource(properties = { "env = tomcat", "doNotifications = false" })
public class SpringWiringTest {
...
#BeforeClass
public static void setup() throws Exception {
SimpleNamingContextBuilder builder = SimpleNamingContextBuilder.emptyActivatedContextBuilder();
DataSource ds = new DriverManagerDataSource();
builder.bind("java:comp/env/abc", ds);
}
...
#Configuration
#ImportResource("file:src/main/webapp/WEB-INF/applicationContext.xml")
public static class Config {
#Bean public String uslDatasourcesList() { return "abc"; }
#Bean public String atgDatasourcesList() { return "abc"; }
#Bean public String uslTableNamePrefixsList() { return "abc"; }
#Bean public String atgTableNamePrefixsList() { return "abc"; }
#Bean public String doNotifications() { return "false"; }
#Bean public DataSource abc() { return new DriverManagerDataSource(); }
}
}
When I run my test, the bottom "Caused by" in the exception says this:
Caused by: javax.naming.NameNotFoundException: Name
[uslDatasourcesList] not bound; 1 bindings: [java:comp/env/abc]
In the alternate version, using the commented-out "#ContextConfiguration" (and commenting out the Config class and its annotations), this error does not occur.
Note that this the meat of my "testResources.xml" file:
<bean id="uslDatasourcesList" class="java.lang.String"> <constructor-arg value="abc"/> </bean>
<bean id="atgDatasourcesList" class="java.lang.String"> <constructor-arg value="abc"/> </bean>
<bean id="uslTableNamePrefixList" class="java.lang.String"> <constructor-arg value="abc"/> </bean>
<bean id="atgTableNamePrefixList" class="java.lang.String"> <constructor-arg value="abc"/> </bean>
<bean id="doNotifications" class="java.lang.String"> <constructor-arg value="false"/> </bean>
<bean id="abc" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
</bean>
Note that the bean mentioned in the error message, "uslDatasourcesList" is defined in both versions, but it's not working in the version with JavaConfig and XML mixed.
It almost appears that the beans in the "#ImportResource" annotation are evaluated on their own, before the beans declared in the JavaConfig class are merged into it.
This is clearly documented in the Spring Reference Manual in the section named Mixing XML, Groovy scripts, and annotated classes.
In summary, ...
... you will have to pick one as the entry point, and that one will have to include or import the other.
Thus, the following should hopefully solve your problem.
#RunWith(SpringRunner.class)
#ContextConfiguration
#TestPropertySource(properties = { "env = tomcat", "doNotifications = false" })
public class SpringWiringTest {
// ...
#Configuration
#ImportResource({"/testApplicationContext.xml", "/testResources.xml"})
static class Config {
// ...
}
}
In order to learn spring integration I've been attempting to create a simple, resilient log processor. I'm also wanting to stick with a java configuration approach.
I've been having a difficult time translating existing XML configuration, mostly due to being so new to spring in general.
In a question on the spring forums Gary Russell presented a similar solution to this using a publish-subscribe + JMS model with a simple XML config.
I've been attempting to translate his suggestion into a Java config, but am stuck. Namely I'm not sure of the proper entities to use for the outbound-channel-adapter, service-activators or how to set the order of messages properly.
Here is Gary's XML config:
<int-file:inbound-channel-adapter id="dispatcher"
directory="spool"
channel="fileChannel">
<int:poller fixed-delay="2000">
<int:transactional/>
</int:poller>
</int-file:inbound-channel-adapter>
<int:channel id="fileChannel" />
<int-file:file-to-string-transformer input-channel="fileChannel" output-channel="dispatchChannel" />
<int:publish-subscribe-channel id="dispatchChannel" />
<int-jms:outbound-channel-adapter id="dispatcherJms" channel="dispatchChannel" order="1"
connection-factory="connectionFactory"
destination="dispatcher.queue" />
<!-- If JMS Send was successful, remove the file (within the transaction)-->
<int:service-activator input-channel="dispatchChannel" order="2"
output-channel="nullChannel"
expression="headers.file_originalFile.delete()">
<bean id="transactionManager" class="org.springframework.jms.connection.JmsTransactionManager">
<property name="connectionFactory" ref="connectionFactory"/>
</bean>
UPDATE
Based on the comments below I've updated the java config.
However I'm still receiving errors and most likely am not understanding the flow and connections between the entities, but the original question has been answered.
#Bean
#Transactional
#InboundChannelAdapter(channel = "dispatchChannel", poller = #Poller(fixedDelay = "2000"))
public MessageSource<?> dispatcher() {
CompositeFileListFilter<File> filters = new CompositeFileListFilter<>();
filters.addFilter(new SimplePatternFileListFilter(sourceFilenamePattern));
//filters.addFilter(persistentFilter());
FileReadingMessageSource source = new FileReadingMessageSource();
source.setAutoCreateDirectory(true);
source.setDirectory(new File(sourceDirectory));
source.setFilter(filters);
return source;
}
#Bean
public MessageChannel fileChannel() {
return new DirectChannel();
}
#Bean
public PublishSubscribeChannel dispatchChannel() {
return new PublishSubscribeChannel();
}
#Autowired
JmsTemplate jmsTemplate;
#Autowired
ConnectionFactory connectionFactory;
#Bean
#Order(1)
#ServiceActivator(inputChannel = "dispatchChannel")
public MessageHandler dispatcherJmsOutboundChannelAdapter(Message<File> message) {
JmsSendingMessageHandler handler = new JmsSendingMessageHandler(jmsTemplate);
handler.setDestinationName("dispatcher.queue");
return handler;
}
#Bean
#Order(2)
#ServiceActivator(inputChannel = "dispatchChannel")
public void removeFile(Message<?> message) {
//message.getHeaders().get(FileHeaders.ORIGINAL_FILE, File.class).delete();
log.info("delete");
}
#Bean
public JmsTransactionManager transactionManager(ConnectionFactory connectionFactory) {
return new JmsTransactionManager(connectionFactory);
}
I'm using spring boot and several starter components, such as activemq. I've added the #Bean for JmsListenerContainerFactory and a #JmsListener, though I'm not sure those are truly necessary.
I couldn't get anything to run until adding #EnableJms to my configuration file as well as #Autowiring the jmstemplate and connectionfactory.
When running, the error I'm receiving now is:
org.springframework.beans.factory.NoSuchBeanDefinitionException:
No qualifying bean of type [org.springframework.messaging.Message] found for dependency
[org.springframework.messaging.Message<?>]:
expected at least 1 bean which qualifies as autowire candidate for this dependency.
Dependency annotations: {}
This one
<int:service-activator input-channel="dispatchChannel" order="2"
output-channel="nullChannel"
expression="headers.file_originalFile.delete()">
is pretty simple in Java:
#ServiceActivator(inputChannel = "dispatchChannel")
public void removeFile(Message<?> message) {
message.getHeaders().get(FileHeaders.ORIGINAL_FILE, File.class).delete();
}
and
<int-jms:outbound-channel-adapter>
is translated to this:
#Bean
#ServiceActivator(inputChannel = "dispatchChannel")
public MessageHandler dispatcherJmsOutboundChannelAdapter() {
JmsSendingMessageHandler handler =
new JmsSendingMessageHandler(new JmsTemplate(this.connectionFactory));
handler.setDestinationName("dispatcher.queue");
return handler;
}
Pay attention to this paragraph in the Reference Manual.
The last piece of jigsaw puzzle is FileWritingMessageHandler
#Bean
public FileWritingMessageHandler fileWritingMessageHandler() {
SpelExpressionParser parser = new SpelExpressionParser();
Expression expression = parser.parseExpression("headers.file_originalFile.delete()");
FileWritingMessageHandler fileWritingMessageHandler = new FileWritingMessageHandler(expression);
fileWritingMessageHandler.setOutputChannel(new NullChannel());
fileWritingMessageHandler.setDeleteSourceFiles(true);
return fileWritingMessageHandler;
}
I am trying to implement XML validation using Spring Integration <int-xml:validating-filter />. I followed the discussion in usage of spring integration's schema validator?. The problem statement is the same but with an additional parameter. Instead to hard coding the value in schema-location="xyz.xsd", rather I want to dynamically select the appropriate xsd file for respective incoming xml or DOMSource inputs.
I also followed http://forum.spring.io/forum/spring-projects/integration/121115-dynamic-schema-location-for-xml-validating-filter-component where Gary Russell mentioned:
There's no direct support for dynamic schemas, but you can provide a
custom XmlValidator using the xml-validator attribute (mutually
exclusive with schema location)
Once you've introspected your document to find the schema you wish to
validate against, simply delegate to a validator that has been
configured to validate against that schema.
You can use a XmlValidatorFactory to create each validator; see the
XmlValidatingMessageSelector for how to create a validator, once you
know the schema location
Since the comments dates back to the year 2012, is there an approach now in spring integration to validate input xml by dynamically selecting appropriate schema? If not can anyone provide an example on how to implement?
Following is my spring integration configuration:
<int:gateway id="applicationServiceGateway" service-interface="abc.IGateway"
default-request-channel="applicationRequestChannel" default-reply-channel="applicationResponseChannel"
error-channel="errorProcessingChannel" />
<int:chain id="serviceRequestValidation" input-channel="applicationRequestChannel" output-channel="responseChannel">
<!-- How to do -->
<int-xml:validating-filter xml-validator="xmlValidator"
schema-type="xml-schema"
throw-exception-on-rejection="true" />
<int:service-activator id="schematronValidationActivator" ref="schematronValidator" method="validate" />
</int:chain>
<bean id="xmlValidator" class="abc.validator.DomSourceValidator" />
Here is my Validator class defined:
import org.springframework.xml.validation.ValidationErrorHandler;
import org.springframework.xml.validation.XmlValidator;
import org.xml.sax.SAXParseException;
public class DomSourceValidator implements XmlValidator {
#Override
public SAXParseException[] validate(Source source) throws IOException {
/* How to implement this method?
Using XPath I can identify the root node from 'source' and then load
the appropriate XSD file. But don't know how to proceed
or what should be 'return'(ed) from here.
Any example is much appreciated.
*/
return null;
}
#Override
public SAXParseException[] validate(Source source, ValidationErrorHandler errorHandler) throws IOException {
// TODO Auto-generated method stub
return null;
}
}
Which is the best way of implementing the XML validator using Spring Integration?
There have been no changes since that comment.
As I said there, your validator needs to use XmlValidatorFactory to create a validator for each schema; then call a specific validator for each message; something like:
String schema = determineSchema(source);
XmlValidator val = lookupValidatorForSchema(schema);
if (val == null) {
// create a new one and add it to the map.
}
return val.validate(source);
If it helps other folks who are trying to do the same
Based on Gary's suggestion, I have come out with an implementation of XmlValidator by dynamically identifying input XML and then selecting appropriate Schema file to apply the validation.
Below is my spring integration configuration:
<int:gateway id="applicationServiceGateway" service-interface="abc.IGateway" default-request-channel="applicationRequestChannel" default-reply-channel="applicationResponseChannel" error-channel="errorProcessingChannel" />
<int:chain id="serviceRequestValidation" input-channel="applicationRequestChannel" output-channel="responseChannel">
<int-xml:validating-filter xml-validator="xmlValidator"
schema-type="xml-schema"
throw-exception-on-rejection="true" /> <!-- a MessageRejectedException is thrown in case validation fails -->
<int:service-activator id="schematronValidationActivator" ref="schematronValidator" method="validate" />
</int:chain>
<bean id="xmlValidator" class="abc.validator.DomSourceValidator">
<constructor-arg>
<map key-type="java.lang.String" value-type="java.lang.String">
<entry key="OTA_AirAvailRQ" value="common/schemas/FS_OTA_AirAvailRQ.xsd" />
<entry key="OTA_AirBookModifyRQ" value="common/schemas/FS_OTA_AirBookModifyRQ.xsd" />
<entry key="OTA_AirBookRQ" value="common/schemas/FS_OTA_AirBookRQ.xsd" />
</map>
</constructor-arg>
</bean>
To demonstrate I have used the OTA schema files to construct a map as constructor-arg. The map key is the root node from the XML file from the gateway and value is the location of the xsd file; and form the key-value pair map.
Refer to the below implementation class how this map is being used to identify the input XML and apply the validation.
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.PostConstruct;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.util.Assert;
import org.springframework.xml.validation.ValidationErrorHandler;
import org.springframework.xml.validation.XmlValidator;
import org.springframework.xml.validation.XmlValidatorFactory;
import org.xml.sax.SAXParseException;
public class DomSourceValidator implements XmlValidator {
private static final Log LOGGER = LogFactory.getLog(DomSourceValidator.class);
private Map<String, String> schemaMap;
private static Map<String, XmlValidator> validatorMap = new HashMap<>();
public DomSourceValidator(Map<String, String> schemaMap) {
this.schemaMap = schemaMap;
}
#PostConstruct
private void init() throws IOException {
LOGGER.info("Constructing Validators from schema resource list ...");
Assert.notEmpty(schemaMap, "No schema resource map found");
if (validatorMap.isEmpty()) {
XmlValidator validator = null;
for (Map.Entry<String, String> entry : schemaMap.entrySet()) {
validator = createValidatorFromResourceUri(entry.getValue());
validatorMap.put(entry.getKey(), validator);
}
}
}
#Override
public SAXParseException[] validate(Source source) throws IOException {
Assert.notNull(schemaMap, "No validator(s) defined");
XmlValidator validator = lookupValidator(source);
return validator.validate(source);
}
#Override
public SAXParseException[] validate(Source source, ValidationErrorHandler errorHandler) throws IOException {
// Skip implementation
return null;
}
private XmlValidator lookupValidator(Source source) {
String reqType = determineRequestType(source);
LOGGER.info("Loading validator for type: " + reqType);
XmlValidator xmlValidator = validatorMap.get(reqType);
Assert.notNull(xmlValidator, "No validator found for type: " + reqType);
return xmlValidator;
}
private String determineRequestType(Source source) {
if (source instanceof DOMSource) {
return ((DOMSource) source).getNode().getFirstChild().getNodeName();
}
return null;
}
private XmlValidator createValidatorFromResourceUri(String schemaResource) throws IOException {
Assert.notNull(schemaResource);
return XmlValidatorFactory.createValidator(new ClassPathResource(schemaResource), XmlValidatorFactory.SCHEMA_W3C_XML);
}
}
As soon as the spring bean id="xmlValidator" is initialized, the #PostConstruct kicks in to create Validator instances using XmlValidatorFactory from the resource URIs to have a pre-initialized validators.
If there is a validation error, a org.springframework.integration.MessageRejectedException: Message was rejected due to XML Validation errors is thrown (ref. throw-exception-on-rejection="true" in the <int-xml:validating-filter />).
The above implementation works perfectly fine for me. One can customize it further, or post another version to achieve the same.
Note
Instead of using a <int-xml:validating-filter />, one can also use a <int:service-activator /> in the <int-chain />, as logically <int-xml:validating-filter /> does not actually do any filter logic. But it serves the purpose.
I am getting an exception Dispatcher has no subscribers on the outboundChannel and can't figure out why. I am sure its something simple, I have stripped back my code to a very simple sample below:
My context is:
<bean id="requestService"
class="com.sandpit.RequestService" />
<integration:channel id="inboundChannel" />
<integration:service-activator id="service"
input-channel="inboundChannel"
output-channel="outboundChannel"
ref="requestService"
method="handleRequest" />
<integration:channel id="outboundChannel" />
<integration:gateway id="gateway"
service-interface="com.sandpit.Gateway"
default-request-channel="inboundChannel"
default-reply-channel="outboundChannel" />
<bean class="com.sandpit.GatewayTester">
<property name="gateway"
ref="gateway" />
</bean>
My Java code is:
public interface Gateway {
String receive();
void send(String message);
}
public class RequestService {
public String handleRequest(String request) {
return "Request received: " + request;
}
}
public class GatewayTester implements ApplicationListener<ContextRefreshedEvent> {
private Gateway gateway;
public void setGateway(Gateway gateway) {
this.gateway = gateway;
}
#Override
public void onApplicationEvent(ContextRefreshedEvent event) {
gateway.send("Hello world!");
System.out.println("FROM SERVICE: " + gateway.receive());
}
}
Note: A breakpoint does tell me that the RequestService is actually handling the request.
receive() with no args needs the reply channel to be a PollableChannel See the documentation.
add <queue/> to the outboundChannel.
Alternatively, You could change your gateway method to be String sendAndReceive(String in) and all will work as expected (and you can even remove the outboundChannel altogether).
In my app I have to process multiple jobs asynchronously from the main application thread and collect the result of each job. I have a plain Java solution that does this using a ExecutorService and a ExecutorCompletionService that collects the job results.
Now I would like to convert my code to a Spring solution. The docs show me how the use the ExecutorService and the #Async annotation, but I am not sure how and if I can collect the results of multiple jobs.
In other words: I am looking for the Spring equivalent of the CompletionService. Is there such a thing?
My current code:
class MyService {
private static ExecutorService executorService;
private static CompletionService<String> taskCompletionService;
// static init block
static {
executorService = Executors.newFixedThreadPool(4);
taskCompletionService = new ExecutorCompletionService<String>(executorService);
// Create thread that keeps looking for results
new Thread(new Runnable() {
#Override
public void run() {
while (true) {
try {
Future<String> future = taskCompletionService.take();
String s = future.get();
LOG.debug(s);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
}).start();
}
// This method can and will be called multiple times,
// so multiple jobs are submitted to the completion service
public void solve(List<Long> ids) throws IOException, SolverException {
String data = createSolverData(ids);
taskCompletionService.submit(new SolverRunner(data, properties));
}
}
You need to consider what's your main goal, because your current code will work fine alongside other Spring-associated classes. Spring provides support for native Java ExecutorService as well as other popular 3rd party library such as Quartz
Probably what you're after is setting up the executor service on the spring container (eg: using following config on your spring beans xml)
<bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<property name="corePoolSize" value="5" />
<property name="maxPoolSize" value="10" />
<property name="queueCapacity" value="25" />
</bean>
And decorate your MyService class with #Service annotation and inject the reference to the executor service
I ended up defining my beans in the Spring application context and injection the completionservice into MyService. Works as a charm.
<task:executor id="solverExecutorService" pool-size="5" queue-capacity="100" />
<spring:bean id="solverCompletionService" class="nl.marktmonitor.solver.service.SolverCompletionService" scope="singleton">
<constructor-arg name="executor" ref="solverExecutorService"/>
</spring:bean>