backends-common/rabbitmq/src/main/java/org/apache/james/backends/rabbitmq/RabbitMQManagementAPI.java - james-project - Git at Google

 /****************************************************************
  * Licensed to the Apache Software Foundation (ASF) under one   *
  * or more contributor license agreements.  See the NOTICE file *
  * distributed with this work for additional information        *
  * regarding copyright ownership.  The ASF licenses this file   *
  * to you under the Apache License, Version 2.0 (the            *
  * "License"); you may not use this file except in compliance   *
  * with the License.  You may obtain a copy of the License at   *
  *                                                              *
  *   http://www.apache.org/licenses/LICENSE-2.0                 *
  *                                                              *
  * Unless required by applicable law or agreed to in writing,   *
  * software distributed under the License is distributed on an  *
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
  * KIND, either express or implied.  See the License for the    *
  * specific language governing permissions and limitations      *
  * under the License.                                           *
  ****************************************************************/

 package org.apache.james.backends.rabbitmq;

 import java.io.IOException;
 import java.security.KeyManagementException;
 import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
 import java.security.UnrecoverableKeyException;
 import java.security.cert.CertificateException;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;

 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.google.common.base.MoreObjects;

 import feign.Client;
 import feign.Feign;
 import feign.Logger;
 import feign.Param;
 import feign.RequestLine;
 import feign.RetryableException;
 import feign.Retryer;
 import feign.auth.BasicAuthRequestInterceptor;
 import feign.codec.ErrorDecoder;
 import feign.jackson.JacksonDecoder;
 import feign.jackson.JacksonEncoder;
 import feign.slf4j.Slf4jLogger;
 import org.apache.commons.lang3.NotImplementedException;
 import org.apache.http.conn.ssl.DefaultHostnameVerifier;
 import org.apache.http.ssl.SSLContextBuilder;
 import org.apache.http.ssl.TrustStrategy;

 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;

 public interface RabbitMQManagementAPI {

     class MessageQueue {
         @JsonProperty("name")
         String name;

         @JsonProperty("vhost")
         String vhost;

         @JsonProperty("auto_delete")
         boolean autoDelete;

         @JsonProperty("durable")
         boolean durable;

         @JsonProperty("exclusive")
         boolean exclusive;

         @JsonProperty("arguments")
         Map<String, String> arguments;

         public String getName() {
             return name;
         }

         public String getVhost() {
             return vhost;
         }

         public boolean isAutoDelete() {
             return autoDelete;
         }

         public boolean isDurable() {
             return durable;
         }

         public boolean isExclusive() {
             return exclusive;
         }

         public Map<String, String> getArguments() {
             return arguments;
         }
     }

     class MessageQueueDetails {
         @JsonProperty("name")
         String name;

         @JsonProperty("vhost")
         String vhost;

         @JsonProperty("auto_delete")
         boolean autoDelete;

         @JsonProperty("durable")
         boolean durable;

         @JsonProperty("exclusive")
         boolean exclusive;

         @JsonProperty("arguments")
         Map<String, String> arguments;

         @JsonProperty("consumer_details")
         List<ConsumerDetails> consumerDetails;

         public String getName() {
             return name;
         }

         public String getVhost() {
             return vhost;
         }

         public boolean isAutoDelete() {
             return autoDelete;
         }

         public boolean isDurable() {
             return durable;
         }

         public boolean isExclusive() {
             return exclusive;
         }

         public Map<String, String> getArguments() {
             return arguments;
         }

         public List<ConsumerDetails> getConsumerDetails() {
             return consumerDetails;
         }
     }

     class ConsumerDetails {
         @JsonProperty("consumer_tag")
         String tag;

         @JsonProperty("activity_status")
         ActivityStatus status;

         public ActivityStatus getStatus() {
             return this.status;
         }

         public String getTag() {
             return this.tag;
         }
     }

     @JsonFormat(shape = JsonFormat.Shape.STRING)
     enum ActivityStatus {
         Waiting("waiting"),
         SingleActive("single_active");

         private final String value;

         ActivityStatus(String value) {
             this.value = value;
         }

         @JsonValue
         String getValue() {
             return value;
         }
     }

     class Exchange {

         @JsonProperty("name")
         String name;

         @JsonProperty("type")
         String type;

         @JsonProperty("auto_delete")
         boolean autoDelete;

         @JsonProperty("durable")
         boolean durable;

         @JsonProperty("internal")
         boolean internal;

         @JsonProperty("arguments")
         Map<String, String> arguments;

         public String getName() {
             return name;
         }

         public String getType() {
             return type;
         }

         public boolean isAutoDelete() {
             return autoDelete;
         }

         public boolean isDurable() {
             return durable;
         }

         public boolean isInternal() {
             return internal;
         }

         public Map<String, String> getArguments() {
             return arguments;
         }

         @Override
         public String toString() {
             return MoreObjects.toStringHelper(this)
                 .add("name", name)
                 .add("type", type)
                 .add("autoDelete", autoDelete)
                 .add("durable", durable)
                 .add("internal", internal)
                 .add("arguments", arguments)
                 .toString();
         }
     }

     class BindingSource {
         private final String source;
         private final String vhost;
         private final String destination;
         private final String destinationType;
         private final String routingKey;
         private final Map<String, String> arguments;
         private final String propertiesKey;

         public BindingSource(@JsonProperty("source") String source,
                              @JsonProperty("vhost") String vhost,
                              @JsonProperty("destination") String destination,
                              @JsonProperty("destination_type") String destinationType,
                              @JsonProperty("routing_key") String routingKey,
                              @JsonProperty("arguments") Map<String, String> arguments,
                              @JsonProperty("properties_key") String propertiesKey) {
             this.source = source;
             this.vhost = vhost;
             this.destination = destination;
             this.destinationType = destinationType;
             this.routingKey = routingKey;
             this.arguments = arguments;
             this.propertiesKey = propertiesKey;
         }

         public String getSource() {
             return source;
         }

         public String getVhost() {
             return vhost;
         }

         public String getDestination() {
             return destination;
         }

         public String getDestinationType() {
             return destinationType;
         }

         public String getRoutingKey() {
             return routingKey;
         }

         public Map<String, String> getArguments() {
             return arguments;
         }

         public String getPropertiesKey() {
             return propertiesKey;
         }

         @Override
         public final boolean equals(Object o) {
             if (o instanceof BindingSource) {
                 BindingSource that = (BindingSource) o;

                 return Objects.equals(this.source, that.source)
                     && Objects.equals(this.vhost, that.vhost)
                     && Objects.equals(this.destination, that.destination)
                     && Objects.equals(this.destinationType, that.destinationType)
                     && Objects.equals(this.routingKey, that.routingKey)
                     && Objects.equals(this.arguments, that.arguments)
                     && Objects.equals(this.propertiesKey, that.propertiesKey);
             }
             return false;
         }

         @Override
         public final int hashCode() {
             return Objects.hash(source, vhost, destination, destinationType, routingKey, arguments, propertiesKey);
         }
     }

     static RabbitMQManagementAPI from(RabbitMQConfiguration configuration) {
         RabbitMQConfiguration.ManagementCredentials credentials = configuration.getManagementCredentials();

         RabbitMQManagementAPI rabbitMQManagementAPI = null;
         try {
             rabbitMQManagementAPI = Feign.builder()
                     .client(getClient(configuration))
                     .requestInterceptor(new BasicAuthRequestInterceptor(credentials.getUser(), new String(credentials.getPassword())))
                     .logger(new Slf4jLogger(RabbitMQManagementAPI.class))
                     .logLevel(Logger.Level.FULL)
                     .encoder(new JacksonEncoder())
                     .decoder(new JacksonDecoder())
                     .retryer(new Retryer.Default())
                     .errorDecoder(RETRY_500)
                     .target(RabbitMQManagementAPI.class, configuration.getManagementUri().toString());
         } catch (KeyManagementException | NoSuchAlgorithmException | CertificateException | KeyStoreException | IOException | UnrecoverableKeyException e) {
             throw new RuntimeException(e);
         }

         return rabbitMQManagementAPI;
     }

     private static Client getClient(RabbitMQConfiguration configuration) throws KeyManagementException, NoSuchAlgorithmException, CertificateException, KeyStoreException, IOException, UnrecoverableKeyException {
         if (configuration.useSslManagement()) {
             SSLContextBuilder sslContextBuilder = new SSLContextBuilder();

             setupSslValidationStrategy(sslContextBuilder, configuration);

             setupClientCertificateAuthentication(sslContextBuilder, configuration);

             SSLContext sslContext = sslContextBuilder.build();

             return new Client.Default(sslContext.getSocketFactory(), getHostNameVerifier(configuration));
         }
         else {
             return new Client.Default(null, null);
         }

     }

     private static HostnameVerifier getHostNameVerifier(RabbitMQConfiguration configuration) {
         switch (configuration.getSslConfiguration().getHostNameVerifier()) {
             case ACCEPT_ANY_HOSTNAME:
                 return ((hostname, session) -> true);
             default:
                 return new DefaultHostnameVerifier();
         }
     }

     private static void setupClientCertificateAuthentication(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws NoSuchAlgorithmException, KeyStoreException, UnrecoverableKeyException, CertificateException, IOException {
         Optional<RabbitMQConfiguration.SSLConfiguration.SSLKeyStore> keyStore = configuration.getSslConfiguration().getKeyStore();

         if (keyStore.isPresent()) {
             RabbitMQConfiguration.SSLConfiguration.SSLKeyStore sslKeyStore = keyStore.get();

             sslContextBuilder.loadKeyMaterial(sslKeyStore.getFile(), sslKeyStore.getPassword(), sslKeyStore.getPassword());
         }
     }

     private static void setupSslValidationStrategy(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws NoSuchAlgorithmException, KeyStoreException, CertificateException, IOException {
         RabbitMQConfiguration.SSLConfiguration.SSLValidationStrategy strategy = configuration
                 .getSslConfiguration()
                 .getStrategy();

         final TrustStrategy TRUST_ALL = (x509Certificates, authType) -> true;

         switch (strategy) {
             case DEFAULT:
                 break;
             case IGNORE:
                 sslContextBuilder.loadTrustMaterial(TRUST_ALL);
                 break;
             case OVERRIDE:
                 applyTrustStore(sslContextBuilder, configuration);
                 break;
             default:
                 throw new NotImplementedException(
                         String.format("unrecognized strategy '%s'", strategy.name()));
         }
     }

     private static SSLContextBuilder applyTrustStore(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws CertificateException, NoSuchAlgorithmException,
             KeyStoreException, IOException {

         RabbitMQConfiguration.SSLConfiguration.SSLTrustStore trustStore = configuration.getSslConfiguration()
                 .getTrustStore()
                 .orElseThrow(() -> new IllegalStateException("SSLTrustStore cannot to be empty"));

         return sslContextBuilder
                 .loadTrustMaterial(trustStore.getFile(), trustStore.getPassword());
     }

     ErrorDecoder RETRY_500 = (methodKey, response) -> {
         if (response.status() == 500) {
             throw new RetryableException(response.status(), "Error encountered, scheduling retry", response.request().httpMethod(), new Date());
         }
         throw new RuntimeException("Non recoverable exception status: " + response.status());
     };

     @RequestLine("GET /api/queues")
     List<MessageQueue> listQueues();

     @RequestLine(value = "GET /api/queues/{vhost}/{name}", decodeSlash = false)
     MessageQueueDetails queueDetails(@Param("vhost") String vhost, @Param("name") String name);

     @RequestLine(value = "DELETE /api/queues/{vhost}/{name}", decodeSlash = false)
     void deleteQueue(@Param("vhost") String vhost, @Param("name") String name);

     @RequestLine(value = "GET /api/exchanges/{vhost}/{name}/bindings/source", decodeSlash = false)
     List<BindingSource> listBindings(@Param("vhost") String vhost, @Param("name") String name);

     @RequestLine("GET /api/exchanges")
     List<Exchange> listExchanges();
 }
	/****************************************************************
	* Licensed to the Apache Software Foundation (ASF) under one *
	* or more contributor license agreements. See the NOTICE file *
	* distributed with this work for additional information *
	* regarding copyright ownership. The ASF licenses this file *
	* to you under the Apache License, Version 2.0 (the *
	* "License"); you may not use this file except in compliance *
	* with the License. You may obtain a copy of the License at *
	* *
	* http://www.apache.org/licenses/LICENSE-2.0 *
	* *
	* Unless required by applicable law or agreed to in writing, *
	* software distributed under the License is distributed on an *
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
	* KIND, either express or implied. See the License for the *
	* specific language governing permissions and limitations *
	* under the License. *
	****************************************************************/

	package org.apache.james.backends.rabbitmq;

	import java.io.IOException;
	import java.security.KeyManagementException;
	import java.security.KeyStoreException;
	import java.security.NoSuchAlgorithmException;
	import java.security.UnrecoverableKeyException;
	import java.security.cert.CertificateException;
	import java.util.Date;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Optional;

	import com.fasterxml.jackson.annotation.JsonFormat;
	import com.fasterxml.jackson.annotation.JsonProperty;
	import com.fasterxml.jackson.annotation.JsonValue;
	import com.google.common.base.MoreObjects;

	import feign.Client;
	import feign.Feign;
	import feign.Logger;
	import feign.Param;
	import feign.RequestLine;
	import feign.RetryableException;
	import feign.Retryer;
	import feign.auth.BasicAuthRequestInterceptor;
	import feign.codec.ErrorDecoder;
	import feign.jackson.JacksonDecoder;
	import feign.jackson.JacksonEncoder;
	import feign.slf4j.Slf4jLogger;
	import org.apache.commons.lang3.NotImplementedException;
	import org.apache.http.conn.ssl.DefaultHostnameVerifier;
	import org.apache.http.ssl.SSLContextBuilder;
	import org.apache.http.ssl.TrustStrategy;

	import javax.net.ssl.HostnameVerifier;
	import javax.net.ssl.SSLContext;

	public interface RabbitMQManagementAPI {

	class MessageQueue {
	@JsonProperty("name")
	String name;

	@JsonProperty("vhost")
	String vhost;

	@JsonProperty("auto_delete")
	boolean autoDelete;

	@JsonProperty("durable")
	boolean durable;

	@JsonProperty("exclusive")
	boolean exclusive;

	@JsonProperty("arguments")
	Map<String, String> arguments;

	public String getName() {
	return name;
	}

	public String getVhost() {
	return vhost;
	}

	public boolean isAutoDelete() {
	return autoDelete;
	}

	public boolean isDurable() {
	return durable;
	}

	public boolean isExclusive() {
	return exclusive;
	}

	public Map<String, String> getArguments() {
	return arguments;
	}
	}

	class MessageQueueDetails {
	@JsonProperty("name")
	String name;

	@JsonProperty("vhost")
	String vhost;

	@JsonProperty("auto_delete")
	boolean autoDelete;

	@JsonProperty("durable")
	boolean durable;

	@JsonProperty("exclusive")
	boolean exclusive;

	@JsonProperty("arguments")
	Map<String, String> arguments;

	@JsonProperty("consumer_details")
	List<ConsumerDetails> consumerDetails;

	public String getName() {
	return name;
	}

	public String getVhost() {
	return vhost;
	}

	public boolean isAutoDelete() {
	return autoDelete;
	}

	public boolean isDurable() {
	return durable;
	}

	public boolean isExclusive() {
	return exclusive;
	}

	public Map<String, String> getArguments() {
	return arguments;
	}

	public List<ConsumerDetails> getConsumerDetails() {
	return consumerDetails;
	}
	}

	class ConsumerDetails {
	@JsonProperty("consumer_tag")
	String tag;

	@JsonProperty("activity_status")
	ActivityStatus status;

	public ActivityStatus getStatus() {
	return this.status;
	}

	public String getTag() {
	return this.tag;
	}
	}

	@JsonFormat(shape = JsonFormat.Shape.STRING)
	enum ActivityStatus {
	Waiting("waiting"),
	SingleActive("single_active");

	private final String value;

	ActivityStatus(String value) {
	this.value = value;
	}

	@JsonValue
	String getValue() {
	return value;
	}
	}

	class Exchange {

	@JsonProperty("name")
	String name;

	@JsonProperty("type")
	String type;

	@JsonProperty("auto_delete")
	boolean autoDelete;

	@JsonProperty("durable")
	boolean durable;

	@JsonProperty("internal")
	boolean internal;

	@JsonProperty("arguments")
	Map<String, String> arguments;

	public String getName() {
	return name;
	}

	public String getType() {
	return type;
	}

	public boolean isAutoDelete() {
	return autoDelete;
	}

	public boolean isDurable() {
	return durable;
	}

	public boolean isInternal() {
	return internal;
	}

	public Map<String, String> getArguments() {
	return arguments;
	}

	@Override
	public String toString() {
	return MoreObjects.toStringHelper(this)
	.add("name", name)
	.add("type", type)
	.add("autoDelete", autoDelete)
	.add("durable", durable)
	.add("internal", internal)
	.add("arguments", arguments)
	.toString();
	}
	}

	class BindingSource {
	private final String source;
	private final String vhost;
	private final String destination;
	private final String destinationType;
	private final String routingKey;
	private final Map<String, String> arguments;
	private final String propertiesKey;

	public BindingSource(@JsonProperty("source") String source,
	@JsonProperty("vhost") String vhost,
	@JsonProperty("destination") String destination,
	@JsonProperty("destination_type") String destinationType,
	@JsonProperty("routing_key") String routingKey,
	@JsonProperty("arguments") Map<String, String> arguments,
	@JsonProperty("properties_key") String propertiesKey) {
	this.source = source;
	this.vhost = vhost;
	this.destination = destination;
	this.destinationType = destinationType;
	this.routingKey = routingKey;
	this.arguments = arguments;
	this.propertiesKey = propertiesKey;
	}

	public String getSource() {
	return source;
	}

	public String getVhost() {
	return vhost;
	}

	public String getDestination() {
	return destination;
	}

	public String getDestinationType() {
	return destinationType;
	}

	public String getRoutingKey() {
	return routingKey;
	}

	public Map<String, String> getArguments() {
	return arguments;
	}

	public String getPropertiesKey() {
	return propertiesKey;
	}

	@Override
	public final boolean equals(Object o) {
	if (o instanceof BindingSource) {
	BindingSource that = (BindingSource) o;

	return Objects.equals(this.source, that.source)
	&& Objects.equals(this.vhost, that.vhost)
	&& Objects.equals(this.destination, that.destination)
	&& Objects.equals(this.destinationType, that.destinationType)
	&& Objects.equals(this.routingKey, that.routingKey)
	&& Objects.equals(this.arguments, that.arguments)
	&& Objects.equals(this.propertiesKey, that.propertiesKey);
	}
	return false;
	}

	@Override
	public final int hashCode() {
	return Objects.hash(source, vhost, destination, destinationType, routingKey, arguments, propertiesKey);
	}
	}

	static RabbitMQManagementAPI from(RabbitMQConfiguration configuration) {
	RabbitMQConfiguration.ManagementCredentials credentials = configuration.getManagementCredentials();

	RabbitMQManagementAPI rabbitMQManagementAPI = null;
	try {
	rabbitMQManagementAPI = Feign.builder()
	.client(getClient(configuration))
	.requestInterceptor(new BasicAuthRequestInterceptor(credentials.getUser(), new String(credentials.getPassword())))
	.logger(new Slf4jLogger(RabbitMQManagementAPI.class))
	.logLevel(Logger.Level.FULL)
	.encoder(new JacksonEncoder())
	.decoder(new JacksonDecoder())
	.retryer(new Retryer.Default())
	.errorDecoder(RETRY_500)
	.target(RabbitMQManagementAPI.class, configuration.getManagementUri().toString());
	} catch (KeyManagementException \| NoSuchAlgorithmException \| CertificateException \| KeyStoreException \| IOException \| UnrecoverableKeyException e) {
	throw new RuntimeException(e);
	}

	return rabbitMQManagementAPI;
	}

	private static Client getClient(RabbitMQConfiguration configuration) throws KeyManagementException, NoSuchAlgorithmException, CertificateException, KeyStoreException, IOException, UnrecoverableKeyException {
	if (configuration.useSslManagement()) {
	SSLContextBuilder sslContextBuilder = new SSLContextBuilder();

	setupSslValidationStrategy(sslContextBuilder, configuration);

	setupClientCertificateAuthentication(sslContextBuilder, configuration);

	SSLContext sslContext = sslContextBuilder.build();

	return new Client.Default(sslContext.getSocketFactory(), getHostNameVerifier(configuration));
	}
	else {
	return new Client.Default(null, null);
	}

	}

	private static HostnameVerifier getHostNameVerifier(RabbitMQConfiguration configuration) {
	switch (configuration.getSslConfiguration().getHostNameVerifier()) {
	case ACCEPT_ANY_HOSTNAME:
	return ((hostname, session) -> true);
	default:
	return new DefaultHostnameVerifier();
	}
	}

	private static void setupClientCertificateAuthentication(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws NoSuchAlgorithmException, KeyStoreException, UnrecoverableKeyException, CertificateException, IOException {
	Optional<RabbitMQConfiguration.SSLConfiguration.SSLKeyStore> keyStore = configuration.getSslConfiguration().getKeyStore();

	if (keyStore.isPresent()) {
	RabbitMQConfiguration.SSLConfiguration.SSLKeyStore sslKeyStore = keyStore.get();

	sslContextBuilder.loadKeyMaterial(sslKeyStore.getFile(), sslKeyStore.getPassword(), sslKeyStore.getPassword());
	}
	}

	private static void setupSslValidationStrategy(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws NoSuchAlgorithmException, KeyStoreException, CertificateException, IOException {
	RabbitMQConfiguration.SSLConfiguration.SSLValidationStrategy strategy = configuration
	.getSslConfiguration()
	.getStrategy();

	final TrustStrategy TRUST_ALL = (x509Certificates, authType) -> true;

	switch (strategy) {
	case DEFAULT:
	break;
	case IGNORE:
	sslContextBuilder.loadTrustMaterial(TRUST_ALL);
	break;
	case OVERRIDE:
	applyTrustStore(sslContextBuilder, configuration);
	break;
	default:
	throw new NotImplementedException(
	String.format("unrecognized strategy '%s'", strategy.name()));
	}
	}

	private static SSLContextBuilder applyTrustStore(SSLContextBuilder sslContextBuilder, RabbitMQConfiguration configuration) throws CertificateException, NoSuchAlgorithmException,
	KeyStoreException, IOException {

	RabbitMQConfiguration.SSLConfiguration.SSLTrustStore trustStore = configuration.getSslConfiguration()
	.getTrustStore()
	.orElseThrow(() -> new IllegalStateException("SSLTrustStore cannot to be empty"));

	return sslContextBuilder
	.loadTrustMaterial(trustStore.getFile(), trustStore.getPassword());
	}

	ErrorDecoder RETRY_500 = (methodKey, response) -> {
	if (response.status() == 500) {
	throw new RetryableException(response.status(), "Error encountered, scheduling retry", response.request().httpMethod(), new Date());
	}
	throw new RuntimeException("Non recoverable exception status: " + response.status());
	};

	@RequestLine("GET /api/queues")
	List<MessageQueue> listQueues();

	@RequestLine(value = "GET /api/queues/{vhost}/{name}", decodeSlash = false)
	MessageQueueDetails queueDetails(@Param("vhost") String vhost, @Param("name") String name);

	@RequestLine(value = "DELETE /api/queues/{vhost}/{name}", decodeSlash = false)
	void deleteQueue(@Param("vhost") String vhost, @Param("name") String name);

	@RequestLine(value = "GET /api/exchanges/{vhost}/{name}/bindings/source", decodeSlash = false)
	List<BindingSource> listBindings(@Param("vhost") String vhost, @Param("name") String name);

	@RequestLine("GET /api/exchanges")
	List<Exchange> listExchanges();
	}