Binding Management

/**
 * Central service for managing bindings between applications and message brokers.
 */
public class BindingService implements BeanFactoryAware, DisposableBean, ApplicationContextAware {
    
    /**
     * Bind a consumer to the specified input name.
     * @param inputTarget the consumer binding target
     * @param inputName the logical input name
     * @return collection of created bindings
     */
    public Collection<Binding<Object>> bindConsumer(Object inputTarget, String inputName);
    
    /**
     * Bind a producer to the specified output name.
     * @param outputTarget the producer binding target
     * @param outputName the logical output name
     * @return the created binding
     */
    public Binding<MessageChannel> bindProducer(Object outputTarget, String outputName);
    
    /**
     * Unbind all consumers for the specified input name.
     * @param inputName the logical input name
     */
    public void unbindConsumers(String inputName);
    
    /**
     * Unbind all producers for the specified output name.
     * @param outputName the logical output name
     */
    public void unbindProducers(String outputName);
    
    /**
     * Get all consumer bindings.
     * @return map of consumer bindings keyed by input name
     */
    public Map<String, List<Binding<Object>>> getConsumerBindings();
    
    /**
     * Get all producer bindings.
     * @return map of producer bindings keyed by output name
     */
    public Map<String, Binding<MessageChannel>> getProducerBindings();
    
    public void setBeanFactory(BeanFactory beanFactory);
    public void setApplicationContext(ApplicationContext applicationContext);
    public void destroy();
}

/**
 * Marker interface for instances that can bind/unbind groups of inputs and outputs.
 */
public interface Bindable {
    
    /**
     * Get the names of all inputs that can be bound.
     * @return set of input names
     */
    Set<String> getInputs();
    
    /**
     * Get the names of all outputs that can be bound.
     * @return set of output names
     */
    Set<String> getOutputs();
    
    /**
     * Create and bind all inputs using the provided binding service.
     * @param bindingService the service to use for binding
     * @return collection of created bindings
     */
    Collection<Binding<Object>> createAndBindInputs(BindingService bindingService);
    
    /**
     * Create and bind all outputs using the provided binding service.
     * @param bindingService the service to use for binding  
     * @return collection of created bindings
     */
    Collection<Binding<Object>> createAndBindOutputs(BindingService bindingService);
    
    /**
     * Unbind all inputs.
     */
    void unbindInputs();
    
    /**
     * Unbind all outputs.
     */
    void unbindOutputs();
    
    /**
     * Bind all inputs using the provided binding service.
     * @param bindingService the service to use for binding
     */
    default void bindInputs(BindingService bindingService) {
        createAndBindInputs(bindingService);
    }
    
    /**
     * Bind all outputs using the provided binding service.
     * @param bindingService the service to use for binding
     */
    default void bindOutputs(BindingService bindingService) {
        createAndBindOutputs(bindingService);
    }
}

/**
 * Factory for creating binding targets.
 */
public interface BindingTargetFactory {
    
    /**
     * Check if this factory can create the specified type of binding target.
     * @param bindingTargetType the target type
     * @return true if this factory can create the target type
     */
    boolean canCreate(Class<?> bindingTargetType);
    
    /**
     * Create a binding target of the specified type.
     * @param name the binding target name
     * @param bindingTargetType the target type
     * @param properties additional properties for target creation
     * @return the created binding target
     */
    Object createInput(String name, Class<?> bindingTargetType, Properties properties);
    
    /**
     * Create an output binding target of the specified type.
     * @param name the binding target name
     * @param bindingTargetType the target type
     * @param properties additional properties for target creation
     * @return the created binding target
     */
    Object createOutput(String name, Class<?> bindingTargetType, Properties properties);
}

/**
 * Factory for subscribable channel binding targets.
 */
public class SubscribableChannelBindingTargetFactory implements BindingTargetFactory, ApplicationContextAware {
    
    public boolean canCreate(Class<?> bindingTargetType);
    public MessageChannel createInput(String name, Class<?> bindingTargetType, Properties properties);
    public MessageChannel createOutput(String name, Class<?> bindingTargetType, Properties properties);
    public void setApplicationContext(ApplicationContext applicationContext);
}

/**
 * Factory for message source binding targets.
 */
public class MessageSourceBindingTargetFactory implements BindingTargetFactory {
    
    public boolean canCreate(Class<?> bindingTargetType);
    public MessageSource<?> createInput(String name, Class<?> bindingTargetType, Properties properties);
    public MessageSource<?> createOutput(String name, Class<?> bindingTargetType, Properties properties);
}

/**
 * Factory for Flux message channel binding targets.
 */
public class FluxMessageChannelBindingTargetFactory implements BindingTargetFactory {
    
    public boolean canCreate(Class<?> bindingTargetType);
    public Object createInput(String name, Class<?> bindingTargetType, Properties properties);
    public Object createOutput(String name, Class<?> bindingTargetType, Properties properties);
}

/**
 * Base factory for creating bindable proxies.
 */
public abstract class AbstractBindableProxyFactory implements Bindable, BeanFactoryAware, ApplicationContextAware {
    
    protected final Class<?> type;
    protected BeanFactory beanFactory;
    protected ApplicationContext applicationContext;
    
    protected AbstractBindableProxyFactory(Class<?> type);
    
    public Set<String> getInputs();
    public Set<String> getOutputs();
    public void bindInputs(BindingService bindingService);
    public void bindOutputs(BindingService bindingService);
    public void unbindInputs();
    public void unbindOutputs();
    
    protected abstract Object createBindableProxy();
    
    public void setBeanFactory(BeanFactory beanFactory);
    public void setApplicationContext(ApplicationContext applicationContext);
}

/**
 * Factory for creating standard bindable proxies.
 */
public class BindableProxyFactory extends AbstractBindableProxyFactory {
    
    public BindableProxyFactory(Class<?> type);
    
    protected Object createBindableProxy();
    public Object invoke(Object proxy, Method method, Object[] args);
}

/**
 * Interface for configuring message channels.
 */
public interface MessageChannelConfigurer {
    
    /**
     * Configure the input channel.
     * @param channel the channel to configure
     * @param channelName the channel name
     */
    void configureInputChannel(MessageChannel channel, String channelName);
    
    /**
     * Configure the output channel.
     * @param channel the channel to configure
     * @param channelName the channel name
     */
    void configureOutputChannel(MessageChannel channel, String channelName);
}

/**
 * Extended configurer for channels and sources.
 */
public interface MessageChannelAndSourceConfigurer extends MessageChannelConfigurer {
    
    /**
     * Configure a pollable message source.
     * @param binding the binding target
     * @param name the source name
     * @param group the consumer group
     */
    void configurePollableSource(Object binding, String name, String group);
}

/**
 * Configurer for message converters.
 */
public class MessageConverterConfigurer implements MessageChannelConfigurer, BeanFactoryAware {
    
    public void configureInputChannel(MessageChannel channel, String channelName);
    public void configureOutputChannel(MessageChannel channel, String channelName);
    public void setBeanFactory(BeanFactory beanFactory);
}

/**
 * Composite configurer that delegates to multiple configurers.
 */
public class CompositeMessageChannelConfigurer implements MessageChannelConfigurer {
    
    private final List<MessageChannelConfigurer> configurers;
    
    public CompositeMessageChannelConfigurer(List<MessageChannelConfigurer> configurers);
    
    public void configureInputChannel(MessageChannel channel, String channelName);
    public void configureOutputChannel(MessageChannel channel, String channelName);
}

/**
 * Base class for binding lifecycle management.
 */
public abstract class AbstractBindingLifecycle implements SmartLifecycle, ApplicationContextAware {
    
    protected ApplicationContext applicationContext;
    protected volatile boolean running;
    
    public void start();
    public void stop();
    public boolean isRunning();
    public int getPhase();
    public boolean isAutoStartup();
    public void stop(Runnable callback);
    
    public void setApplicationContext(ApplicationContext applicationContext);
    
    protected abstract void doStartWithBindingService(BindingService bindingService);
    protected abstract void doStopWithBindingService(BindingService bindingService);
}

/**
 * Lifecycle management for input bindings.
 */
public class InputBindingLifecycle extends AbstractBindingLifecycle {
    
    private final Bindable bindable;
    private final Collection<String> inputNames;
    
    public InputBindingLifecycle(Bindable bindable, Collection<String> inputNames);
    
    protected void doStartWithBindingService(BindingService bindingService);
    protected void doStopWithBindingService(BindingService bindingService);
}

/**
 * Lifecycle management for output bindings.
 */
public class OutputBindingLifecycle extends AbstractBindingLifecycle {
    
    private final Bindable bindable;
    private final Collection<String> outputNames;
    
    public OutputBindingLifecycle(Bindable bindable, Collection<String> outputNames);
    
    protected void doStartWithBindingService(BindingService bindingService);
    protected void doStopWithBindingService(BindingService bindingService);
}

/**
 * Controller for managing bindings lifecycle.
 */
public class BindingsLifecycleController implements ApplicationContextAware {
    
    private ApplicationContext applicationContext;
    
    /**
     * Change the state of a binding.
     * @param name the binding name
     * @param state the desired state
     */
    public void changeState(String name, State state);
    
    /**
     * Query the states of all bindings.
     * @return map of binding states keyed by name
     */
    public Map<String, List<BindingInformation>> queryStates();
    
    /**
     * Query the state of a specific binding.
     * @param name the binding name
     * @return list of binding information for the named binding
     */
    public List<BindingInformation> queryState(String name);
    
    public void setApplicationContext(ApplicationContext applicationContext);
    
    /**
     * Information about a binding's current state.
     */
    public static class BindingInformation {
        private final String bindingName;
        private final State state;
        private final String group;
        private final boolean pausable;
        
        public BindingInformation(String bindingName, State state, String group, boolean pausable);
        
        public String getBindingName();
        public State getState();
        public String getGroup();
        public boolean isPausable();
    }
}

/**
 * Callback interface for new destination binding configuration.
 * @param <T> the binding target type
 */
public interface NewDestinationBindingCallback<T> {
    
    /**
     * Configure a new destination binding.
     * @param channelName the channel name
     * @param channel the channel being bound
     * @param producerProperties producer properties for the binding
     * @param extendedProducerProperties extended producer properties
     */
    void configure(String channelName, T channel, ProducerProperties producerProperties, Object extendedProducerProperties);
}

/**
 * Channel interceptor for partitioning messages.
 */
public class DefaultPartitioningInterceptor implements ChannelInterceptor, BeanFactoryAware {
    
    private BeanFactory beanFactory;
    
    /**
     * Intercept message sending to add partition information.
     * @param message the message being sent
     * @param channel the channel
     * @return the message with partition information added
     */
    public Message<?> preSend(Message<?> message, MessageChannel channel);
    
    public void setBeanFactory(BeanFactory beanFactory);
}

/**
 * Defines supported bindable features.
 */
public class SupportedBindableFeatures {
    
    private boolean synchronousConsumer = false;
    private boolean pollableConsumer = false;
    private boolean routeToDlq = false;
    
    public boolean isSynchronousConsumer();
    public void setSynchronousConsumer(boolean synchronousConsumer);
    
    public boolean isPollableConsumer();
    public void setPollableConsumer(boolean pollableConsumer);
    
    public boolean isRouteToDlq();
    public void setRouteToDlq(boolean routeToDlq);
}

/**
 * Router that is aware of binder configuration.
 */
public class BinderAwareRouter extends AbstractMappingMessageRouter implements ApplicationContextAware {
    
    private ApplicationContext applicationContext;
    
    protected String getChannelKey(Message<?> message);
    public void setApplicationContext(ApplicationContext applicationContext);
}

/**
 * Listener for context start after refresh events.
 */
public class ContextStartAfterRefreshListener implements ApplicationListener<ContextRefreshedEvent> {
    
    public void onApplicationEvent(ContextRefreshedEvent event);
}

import org.springframework.cloud.stream.binding.*;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.messaging.MessageChannel;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

// Creating a bindable service
@Component
public class MyMessageService implements Bindable {
    
    private final Map<String, MessageChannel> inputs = new HashMap<>();
    private final Map<String, MessageChannel> outputs = new HashMap<>();
    
    @Override
    public Set<String> getInputs() {
        return inputs.keySet();
    }
    
    @Override
    public Set<String> getOutputs() {
        return outputs.keySet();
    }
    
    @Override
    public void bindInputs(BindingService bindingService) {
        for (Map.Entry<String, MessageChannel> entry : inputs.entrySet()) {
            bindingService.bindConsumer(entry.getValue(), entry.getKey());
        }
    }
    
    @Override
    public void bindOutputs(BindingService bindingService) {
        for (Map.Entry<String, MessageChannel> entry : outputs.entrySet()) {
            bindingService.bindProducer(entry.getValue(), entry.getKey());
        }
    }
    
    @Override
    public void unbindInputs() {
        // Implementation for unbinding inputs
    }
    
    @Override
    public void unbindOutputs() {
        // Implementation for unbinding outputs
    }
    
    public void addInput(String name, MessageChannel channel) {
        inputs.put(name, channel);
    }
    
    public void addOutput(String name, MessageChannel channel) {
        outputs.put(name, channel);
    }
}

// Using BindingService directly
@Service
public class DynamicBindingService {
    
    private final BindingService bindingService;
    
    public DynamicBindingService(BindingService bindingService) {
        this.bindingService = bindingService;
    }
    
    public void createDynamicConsumer(String inputName) {
        MessageChannel channel = new DirectChannel();
        channel.subscribe(message -> {
            System.out.println("Received: " + message.getPayload());
        });
        
        Collection<Binding<Object>> bindings = bindingService.bindConsumer(channel, inputName);
        // Store bindings for later cleanup if needed
    }
    
    public void createDynamicProducer(String outputName) {
        MessageChannel channel = new DirectChannel();
        Binding<MessageChannel> binding = bindingService.bindProducer(channel, outputName);
        
        // Now you can send messages through this channel
        channel.send(MessageBuilder.withPayload("Hello World").build());
    }
}

// Custom channel configurer
@Component
public class CustomChannelConfigurer implements MessageChannelConfigurer {
    
    @Override
    public void configureInputChannel(MessageChannel channel, String channelName) {
        if (channel instanceof AbstractMessageChannel) {
            AbstractMessageChannel abstractChannel = (AbstractMessageChannel) channel;
            // Add custom interceptors
            abstractChannel.addInterceptor(new MyCustomInterceptor());
        }
    }
    
    @Override
    public void configureOutputChannel(MessageChannel channel, String channelName) {
        if (channel instanceof AbstractMessageChannel) {
            AbstractMessageChannel abstractChannel = (AbstractMessageChannel) channel;
            // Add custom interceptors for output
            abstractChannel.addInterceptor(new MyOutputInterceptor());
        }
    }
}

// Managing binding lifecycle
@Component
public class BindingController {
    
    private final BindingsLifecycleController lifecycleController;
    
    public BindingController(BindingsLifecycleController lifecycleController) {
        this.lifecycleController = lifecycleController;
    }
    
    public void pauseBinding(String bindingName) {
        lifecycleController.changeState(bindingName, State.PAUSED);
    }
    
    public void resumeBinding(String bindingName) {
        lifecycleController.changeState(bindingName, State.RESUMED);
    }
    
    public void stopBinding(String bindingName) {
        lifecycleController.changeState(bindingName, State.STOPPED);
    }
    
    public Map<String, List<BindingsLifecycleController.BindingInformation>> getAllBindingStates() {
        return lifecycleController.queryStates();
    }
}