✨ 完善 stater，添加遗嘱消息配置。

mica-mqtt-core/src/main/java/net/dreamlu/iot/mqtt/core/client/MqttWillMessage.java

@@ -114,6 +114,10 @@ public final class MqttWillMessage {
 		}
 
 		public MqttWillMessage build() {
+			// 遗嘱标志被设置为 false，遗嘱 QoS 也必须设置为 0。
+			if (!this.retain && MqttQoS.AT_MOST_ONCE != this.qos) {
+				throw new IllegalArgumentException("WillMessage retain is false and QoS must be 0");
+			}
 			return new MqttWillMessage(this.topic, this.message, this.retain, this.qos, this.willProperties);
 		}
 	}

mica-mqtt-spring-boot-starter/src/main/java/net/dreamlu/iot/mqtt/spring/client/MqttClientConfiguration.java

@@ -18,11 +18,15 @@ package net.dreamlu.iot.mqtt.spring.client;
 
 import net.dreamlu.iot.mqtt.core.client.MqttClient;
 import net.dreamlu.iot.mqtt.core.client.MqttClientCreator;
+import net.dreamlu.iot.mqtt.core.client.MqttWillMessage;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.util.StringUtils;
+
+import java.nio.charset.StandardCharsets;
 
 /**
  * mqtt client 配置
@@ -62,6 +66,18 @@ public class MqttClientConfiguration {
 		if (reInterval1 != null && reInterval1 > 0) {
 			clientCreator.reInterval(reInterval1);
 		}
+		// 构造遗嘱消息
+		MqttClientProperties.WillMessage willMessage = properties.getWillMessage();
+		if (willMessage != null && StringUtils.hasText(willMessage.getTopic())) {
+			MqttWillMessage.Builder builder = MqttWillMessage.builder();
+			builder.topic(willMessage.getTopic())
+				.qos(willMessage.getQos())
+				.retain(willMessage.isRetain());
+			if (StringUtils.hasText(willMessage.getMessage())) {
+				builder.message(willMessage.getMessage().getBytes(StandardCharsets.UTF_8));
+			}
+			clientCreator.willMessage(builder.build());
+		}
 		// 自定义处理
 		customizers.ifAvailable((customizer) -> customizer.customize(clientCreator));
 		return clientCreator;

mica-mqtt-spring-boot-starter/src/main/java/net/dreamlu/iot/mqtt/spring/client/MqttClientProperties.java

@@ -20,6 +20,7 @@ import lombok.Getter;
 import lombok.Setter;
 import net.dreamlu.iot.mqtt.codec.ByteBufferAllocator;
 import net.dreamlu.iot.mqtt.codec.MqttConstant;
+import net.dreamlu.iot.mqtt.codec.MqttQoS;
 import net.dreamlu.iot.mqtt.codec.MqttVersion;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -101,5 +102,30 @@ public class MqttClientProperties {
 	 * ByteBuffer Allocator，支持堆内存和堆外内存，默认为：堆内存
 	 */
 	private ByteBufferAllocator bufferAllocator = ByteBufferAllocator.HEAP;
+	/**
+	 * 遗嘱消息
+	 */
+	private WillMessage willMessage;
+
+	@Getter
+	@Setter
+	public static class WillMessage {
+		/**
+		 * 遗嘱消息 topic
+		 */
+		private String topic;
+		/**
+		 * 遗嘱消息 qos，默认： qos0
+		 */
+		private MqttQoS qos = MqttQoS.AT_MOST_ONCE;
+		/**
+		 * 遗嘱消息 payload
+		 */
+		private String message;
+		/**
+		 * 遗嘱消息保留标识符，默认: false
+		 */
+		private boolean retain = false;
+	}
 
 }

mica-mqtt-spring-boot-starter/src/main/java/net/dreamlu/iot/mqtt/spring/server/MqttServerConfiguration.java

@@ -78,7 +78,8 @@ public class MqttServerConfiguration {
 			.heartbeatTimeout(properties.getHeartbeatTimeout())
 			.readBufferSize(properties.getReadBufferSize())
 			.maxBytesInMessage(properties.getMaxBytesInMessage())
-			.bufferAllocator(properties.getBufferAllocator());
+			.bufferAllocator(properties.getBufferAllocator())
+			.maxClientIdLength(properties.getMaxClientIdLength());
 		if (properties.isDebug()) {
 			serverCreator.debug();
 		}

mica-mqtt-spring-boot-starter/src/main/java/net/dreamlu/iot/mqtt/spring/server/MqttServerProperties.java

@@ -72,6 +72,10 @@ public class MqttServerProperties {
 	 * debug
 	 */
 	private boolean debug = false;
+	/**
+	 * mqtt 3.1 会校验此参数
+	 */
+	private int maxClientIdLength = MqttConstant.DEFAULT_MAX_CLIENT_ID_LENGTH;
 	/**
 	 * ssl 配置
 	 */