Develop Reference

Modify #JMSListener destination on-the-fly on Spring Boot

I have developed a #JMSListener that gets the destination from Java properties and works just fine.
But now I would need to be able to change the "destination" of the queue on runtime without having to reset the whole application, and even if I modify the Properties on runtime, the queue "destination" does not change.
Here is how We are implementing the #JMSListener:
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jms.annotation.JmsListener;
import org.springframework.jms.support.converter.MessageConverter;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.interceptor.TransactionAspectSupport;
#Component("b2b.CCRReceiver")
#Slf4j
public class CCRReceiver {
//SOME_VARIABLES
#Transactional
#JmsListener(destination = "${tibco.configuration.queues.upsert}", containerFactory = "jmsFactory", concurrency = "${jms.concurrency}")
public void receiveMessage(Message message) {
//DO_SOME_STUFF
}
}
As you can see, I get the destination from a Value Expression the first time and it works fine, but then I don't know how to access the JMSListener and change it's destination.
Can this be done? Is there any way to change the destination?
Or I will have to implement this JMS Listener in an other way that allows me to do this?

This should work:
Give the listener an id property
Auto wire the JmsListenerEndpointRegistry (or otherwise get a reference to it)
registry.getListenerContainer("myListener").stop();
registry.getListenerContainer("myListener").shutdown();
((AbstractMessageListenerContainer) registry.getListenerContainer("myListener"))
.setDestinationName("newOne")
registry.getListenerContainer("myListener").initialize();
registry.getListenerContainer("myListener").start();

I solve this problem work with a component Listener Thread. Using TaskExecutor and ApplicationContext to manage. You can create at runtime. I'm still working on it. I'll try Gary Russell's suggestion too.
Sorry about english. Feel free to correct.
applicationContext.getBean(ExampleListenerJMS.class);
...
taskExecutor.execute(exampleListenerJMS);
The class listener "implements Runnable, MessageListener" with a implementation getting custom connection managers (activemq servers different).
#Component
#Scope("application")
public class ExampleListenerJMS implements Runnable, MessageListener {
private EspecificManagerJMS jms = new EspecificManagerJMS();
#Override
public void run() {
customAndChekingActions();
}
protected void customAndChekingActions() {
...
try {
Destination destination = jms.getSession().createQueue(queue);
MessageConsumer consumer = jms.getSession().createConsumer(destination);
consumer.setMessageListener(this);
...
} catch (JMSException e) {
e.printStackTrace();
...
}
}
#Override
public void onMessage(Message message) {
...
}
I hope it helped you

How do I mock a Session in Ratpack with RequestFixture?

What I'm trying to do is test an authentication handler, but my problem boils down to having no Session instance in the registry.
An example test:
package whatever
import groovy.transform.CompileStatic
import ratpack.groovy.handling.GroovyChainAction
import ratpack.groovy.test.handling.GroovyRequestFixture
import ratpack.http.Status
import ratpack.session.Session
import spock.lang.Specification
class SessionChainTest extends Specification {
GroovyChainAction sessionChain = new GroovyChainAction() {
#Override
#CompileStatic
void execute() throws Exception {
get('foo') {
Session s = get Session
// Stuff using session here
}
}
}
def "should get session"() {
given:
def result = GroovyRequestFixture.handle(sessionChain) {
uri 'foo'
method 'GET'
}
expect:
result.status == Status.OK
// If the server threw, rethrow that
Throwable t = result.exception(Throwable)
if (t) throw t // <<< Throws NotInRegistryException because no Session in registry
}
}
(The extra rethrow is in there to allow us to see the exception thrown within the ratpack test, because by default it is caught and stashed in the result.)
I know that in principle I could create a Session instance and add it to the registry with a registry { add <Session instance> } block, but I've delved into the Ratpack code, and creating a Session object requires getting a lot of disparate other components and passing them to SessionModule#sessionAdaptor (or the DefaultSession constructor). I can't find any examples of that being done, it appears this call is handled by Guice dependency-injection magic I can't unpick.
The usual way to do it in an application is to use a bind { module SessionModule } block but this isn't accessible from the context of RequestFixture#execute.
As sessions are bread and butter for any web application, my hunch is that this may be an easily solved problem, I just haven't found the right way to do it?

You can access Registry through GroovyRequestFixture.handle(handler, closure) method call and you can e.g. register mocked Session object:
GroovyRequestFixture.handle(sessionChain) {
uri 'foo'
method 'GET'
registry { r ->
r.add(Session, session)
}
}
Take a look at following example:
import groovy.transform.CompileStatic
import ratpack.exec.Promise
import ratpack.groovy.handling.GroovyChainAction
import ratpack.groovy.test.handling.GroovyRequestFixture
import ratpack.http.Status
import ratpack.jackson.internal.DefaultJsonRender
import ratpack.session.Session
import spock.lang.Specification
import static ratpack.jackson.Jackson.json
class SessionChainTest extends Specification {
Session session = Mock(Session) {
get('test') >> Promise.value(Optional.of('Lorem ipsum'))
}
GroovyChainAction sessionChain = new GroovyChainAction() {
#Override
#CompileStatic
void execute() throws Exception {
get('foo') {
Session s = get Session
s.get('test').map { Optional<String> o ->
o.orElse(null)
}.flatMap { value ->
Promise.value(value)
}.then {
render(json([message: it]))
}
}
}
}
def "should get session"() {
given:
def result = GroovyRequestFixture.handle(sessionChain) {
uri 'foo'
method 'GET'
registry { r ->
r.add(Session, session)
}
}
expect:
result.status == Status.OK
and:
result.rendered(DefaultJsonRender).object == [message: 'Lorem ipsum']
}
}
In this test I mock Session object for key test to store Lorem ipsum text. When running this test, both assertions pass.
Alternative approach: registering Guice.registry()
If you don't want to use mocked Session object you can try replacing default Ratpack's Registry with a Guice registry object. Firstly, initialize a function that creates Guice registry and add SessionModule via bindings:
static Function<Registry, Registry> guiceRegistry = Guice.registry { bindings ->
bindings.module(new SessionModule())
}
Next inside execute() method of GroovyChainAction you can replace the default registry by calling:
register(guiceRegistry.apply(registry))
No mocks anymore, but in this case you can't access Session object outside request scope, so you wont be able to add anything to the session in preparation stage of your test. Below you can find full example:
import groovy.transform.CompileStatic
import ratpack.exec.Promise
import ratpack.func.Function
import ratpack.groovy.handling.GroovyChainAction
import ratpack.groovy.test.handling.GroovyRequestFixture
import ratpack.guice.Guice
import ratpack.http.Status
import ratpack.jackson.internal.DefaultJsonRender
import ratpack.registry.Registry
import ratpack.session.Session
import ratpack.session.SessionModule
import spock.lang.Specification
import static ratpack.jackson.Jackson.json
class SessionChainTest extends Specification {
static Function<Registry, Registry> guiceRegistry = Guice.registry { bindings ->
bindings.module(new SessionModule())
}
GroovyChainAction sessionChain = new GroovyChainAction() {
#Override
#CompileStatic
void execute() throws Exception {
register(guiceRegistry.apply(registry))
get('foo') {
Session s = get Session
s.get('test').map { Optional<String> o ->
o.orElse(null)
}.flatMap { value ->
Promise.value(value)
}.then {
render(json([message: it]))
}
}
}
}
def "should get session"() {
given:
def result = GroovyRequestFixture.handle(sessionChain) {
uri 'foo'
method 'GET'
}
expect:
result.status == Status.OK
and:
result.rendered(DefaultJsonRender).object == [message: null]
}
}
Hope it helps.

Adding REST route to an existing Jetty endpoint in Camel at runtime

I have been inventing a way how to work around the problem of adding consumers to a jetty endpoint (it does not allow multiple consumers). The way we do it in our company is to build our own router and a broadcasting endpoint which consumes from jetty and routes requests to underlying "subscriptions". Only one of them will eventually process the request. It kind of works but it's not completely ok, since recently when updating to latest Camel we have found our custom built component to leak memory and in general I consider using built-in functionality over custom hacks.
I started investigating the Camel REST API and found it very nice and pretty much replacing our home-grown component apart from one thing - you cannot re-configure it at runtime - you have to stop the context basically for this to work. Below I include my unit test with a happy path and the path that fails. Frankly I think is a bug, but if there is a legitimate way to achieve what I want, I'd like to hear sound advice:
package com.anydoby.camel;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.commons.io.IOUtils;
import org.junit.Before;
import org.junit.Test;
/**
* Test tries to add/remove routes at runtime.
*/
public class RoutesTest {
private DefaultCamelContext ctx;
#Before
public void pre() throws Exception {
ctx = new DefaultCamelContext();
new RouteBuilder(ctx) {
#Override
public void configure() throws Exception {
restConfiguration("jetty").host("localhost").port(8080);
rest("/")
.get("/issues/{isin}").route().id("issues")
.process(e -> e.getOut().setBody("Here's your issue " + e.getIn().getHeader("isin"))).endRest()
.get("/listings").route().id("listings").process(e -> e.getOut().setBody("some listings"));
}
}.addRoutesToCamelContext(ctx);
ctx.start();
}
#Test
public void test() throws IOException {
{
InputStream stream = new URL("http://localhost:8080/issues/35").openStream();
assertEquals("Here's your issue 35", IOUtils.toString(stream));
}
{
InputStream stream = new URL("http://localhost:8080/listings").openStream();
assertEquals("some listings", IOUtils.toString(stream));
}
}
#Test
public void disableRoute() throws Exception {
ctx.stopRoute("issues");
ctx.removeRoute("issues");
try (InputStream stream = new URL("http://localhost:8080/issues/35").openStream()) {
fail();
} catch (Exception e) {
}
new RouteBuilder(ctx) {
#Override
public void configure() throws Exception {
rest().get("/issues/{isin}/{sedol}").route().id("issues")
.process(e -> e.getOut()
.setBody("Here's your issue " + e.getIn().getHeader("isin") + ":" + e.getIn().getHeader("sedol")))
.endRest();
}
}.addRoutesToCamelContext(ctx);
{
InputStream stream = new URL("http://localhost:8080/issues/35/65").openStream();
assertEquals("Here's your issue 35:65", IOUtils.toString(stream));
}
}
}
The disableRoute() test fails since I cannot add another consumer to an existing endpoint.
So my question is - "is there a way to add a new URL mapping to a restful camel-jetty endpoint"? If you do it during first configuration it works fine, but when later you want to reconfigure one of the routes the error is:
org.apache.camel.FailedToStartRouteException: Failed to start route because of Multiple consumers for the same endpoint is not allowed: jetty:http://localhost:8080/issues/%7Bisin%7D/%7Bsedol%7D?httpMethodRestrict=GET

How to implement a SocketImplFactory using systems default sockets

I have a small problem with implementing a own SocketImplFactory in Java.
My goal is to write a factory which offers me a way to close all open sockets with one simple method call. So I only want to have a kind of "proxy factory" which stores all the created sockets in a list. On this list I could perform all the actions I need.
I tried to implement it like this:
package java.net;
import java.io.IOException;
import java.net.SocketImpl;
import java.net.SocketImplFactory;
import java.util.LinkedList;
import java.util.List;
import org.apache.commons.io.IOUtils;
import com.crosscloud.applicationlayer.logger.CCLogger;
public class CCSocketImplFactory implements SocketImplFactory
{
private List<SocketImpl> _openSockets;
public CCSocketImplFactory()
{
_openSockets = new LinkedList<>();
}
#Override
public SocketImpl createSocketImpl()
{
SocketImpl impl = new SocksSocketImpl();
_openSockets.add(impl);
return impl;
}
public void closeAll()
{
_openSockets.forEach((socket)->
{
try
{
socket.close();
}
catch (Exception e)
{
logException(this, e);
}
});
}
public static CCSocketImplFactory register()
{
CCSocketImplFactory fact = new CCSocketImplFactory();
try
{
Socket.setSocketImplFactory(fact);
}
catch (IOException e)
{
logException(CCSocketImplFactory.class, e);
}
return fact;
}
The problem I have now is that I have to create the class in the package java.net because the class SocksSocketImpl(In my opinion this should be the standard type) is only visible in this package.
When I now want to run the code I get a SecurityException because the package name is probhibited.
Is there a workaround for my problem?
Thank you!

It appears that you are trying to use only one class from java.net There is no need to move you class tot hat package just to create an instance of it. I suggest using reflection instead.
Constructor cons = Class.forName("java.net.SocksSocketImpl").getDeclaredConstructor();
cons.setAccessible(true);
SocketImpl si = (SocketImpl) cons.newInstance();
However using SOCKS by default is likely to be a bad idea as it will change the default not just for your sockets, but all sockets even ones for internal use such as JMX or VisualVM.

What would be an alternative instead of always using SocksSocketImpl?
I also found this example which shows some extended possibilities of this method.
Finding out what network sockets are open in the current Java VM

How to use custom PolicySpi

I'm trying to implement a custom java.security.Permission type, which should be checked at runtime (so no policy file, but in code). This checking is done by a java.security.Policy. I understood I should implement my own java.security.PolicySpi for this.
I cannot find any explanation on how to initialise and use a PolicySpi, or is there a better way to do this?

Checking permissions
In your question you stated that you then want to check the permission with java.security.Policy, but without using a spi.policy file.
From the PolicySpi API, you can see that a PolicySpi object features 4 methods:
engineGetPermissions(CodeSource codesource)
engineGetPermissions(ProtectionDomain domain)
engineImplies(ProtectionDomain domain, Permission permission)
engineRefresh()
However, you might not need PolicySpi as there are easier solutions to check permissions.
See:
Security Manager vs Access Controller
AccessController usage
Since you haven't specified what kind of permission you will grant, I will assume it is a permission concerning a java.security.CodeSource object.
To check all current permissions for a file:
public static void main(String[] args) {
CodeSource source;
try {
source = new CodeSource(new URL("file:/c:/*"), (java.security.cert.Certificate[]) null);
Policy policy = Policy.getPolicy();
System.out.println(policy.getPermissions(source));
} catch (IOException e) {
e.printStackTrace();
}
}
A nice example for the SecurityManager checkPermission() is this tutorial.
For checking specific FilePermissions, you can use:
FilePermission perm = new FilePermission("path/file", "read");
AccessController.checkPermission(perm);
Granting permissions
Granting permissions at runtime can be done with java.lang.RuntimePermission.
For other examples of how to grant permissions to a file, I suggest you read the following:
Access Control Mechanisms and Algorithms
Configuring spi.policy files
Security Managers and Permissions
That should bring you a long way! Good luck!

The previous answer lists alternatives to using PolicySpi (and more generally custom Policy implementations ). This answer will instead give a simplistic example on how a PolicySpi implementation can actually be used as a replacement of the system-default Policy.
Author a JCA Provider.
package com.example;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.Provider;
public final class TestProvider extends Provider {
private static final long serialVersionUID = 5544432861418770903L;
public TestProvider() {
super("TestProvider", 1, "TestProvider 1.0");
AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
putService(new TestPolicySpiService(this));
return null;
});
}
}
Author the sole Service descriptor encapsulated by the provider.
package com.example;
import java.security.Policy.Parameters;
import java.security.PolicySpi;
import java.security.Provider;
import java.security.Provider.Service;
import java.util.Collections;
final class TestPolicySpiService extends Service {
TestPolicySpiService(Provider p) {
super(p, "Policy", "TestPolicy", PolicySpi.class.getName(), Collections.emptyList(), Collections.emptyMap());
}
#Override
public PolicySpi newInstance(Object constructorParameter) {
Parameters policyParams = null;
if (constructorParameter instanceof Parameters) {
policyParams = (Parameters) constructorParameter;
}
return new TestPolicySpi(policyParams);
}
#Override
public boolean supportsParameter(Object parameter) {
return parameter instanceof Parameters;
}
}
Author the actual service (the PolicySpi implementation in this case) that the service descriptor produces.
package com.example;
import java.security.Permission;
import java.security.Policy.Parameters;
import java.security.PolicySpi;
import java.security.ProtectionDomain;
final class TestPolicySpi extends PolicySpi {
TestPolicySpi(Parameters policyParams) {}
#Override
protected boolean engineImplies(ProtectionDomain domain, Permission permission) {
// deny unconditionally
return false;
}
}
Register the provider either statically, by modifying the security.provider.n properties in JAVA_HOME/lib/security/java.security, or programmatically, via java.security.Security.addProvider(Provider) / java.security.Security.insertProviderAt(Provider, int).
Replace the default Policy.
package com.example;
import java.security.NoSuchAlgorithmException;
import java.security.Policy;
public class Main {
public static void main(String... args) throws NoSuchAlgorithmException {
// the following assumes that the provider has been statically registered
Policy.setPolicy(Policy.getInstance("TestPolicy", null));
System.setSecurityManager(new SecurityManager());
// test
System.out.println(System.getProperty("user.home")); // should raise AccessControlException
}
}
Is there a better way to do this?
There certainly is a less involved way, as long as the consequent tight coupling between application and policy does not irk you too badly: Just subclass Policy directly and pass an instance of your implementation to Policy.setPolicy(Policy).
Further reading:
Java Cryptography Architecture (JCA) Reference Guide
How to Implement a Provider in the Java Cryptography Architecture
Standard Algorithm Name Documentation for JDK 8
Troubleshooting Security

As of Java 6, the default implementation for PolicySpi is sun.security.provider.PolicySpiFile. You can get inspired from the source code of PolicySpiFile:
package sun.security.provider;
import java.security.CodeSource;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.Policy;
import java.security.PolicySpi;
import java.security.ProtectionDomain;
import java.security.URIParameter;
import java.net.MalformedURLException;
/**
* This class wraps the PolicyFile subclass implementation of Policy
* inside a PolicySpi implementation that is available from the SUN provider
* via the Policy.getInstance calls.
*
*/
public final class PolicySpiFile extends PolicySpi {
private PolicyFile pf;
public PolicySpiFile(Policy.Parameters params) {
if (params == null) {
pf = new PolicyFile();
} else {
if (!(params instanceof URIParameter)) {
throw new IllegalArgumentException
("Unrecognized policy parameter: " + params);
}
URIParameter uriParam = (URIParameter)params;
try {
pf = new PolicyFile(uriParam.getURI().toURL());
} catch (MalformedURLException mue) {
throw new IllegalArgumentException("Invalid URIParameter", mue);
}
}
}
protected PermissionCollection engineGetPermissions(CodeSource codesource) {
return pf.getPermissions(codesource);
}
protected PermissionCollection engineGetPermissions(ProtectionDomain d) {
return pf.getPermissions(d);
}
protected boolean engineImplies(ProtectionDomain d, Permission p) {
return pf.implies(d, p);
}
protected void engineRefresh() {
pf.refresh();
}
}