net.dreamlu.iot.mqtt.codec.MqttCodecUtil Maven / Gradle / Ivy
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/*
* Copyright 2014 The Netty Project
*
* The Netty Project 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:
*
* https://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 net.dreamlu.iot.mqtt.codec;
import org.tio.core.ChannelContext;
import static net.dreamlu.iot.mqtt.codec.MqttConstant.MIN_CLIENT_ID_LENGTH;
/**
* 编解码工具
*
* @author netty
* @author L.cm
*/
public final class MqttCodecUtil {
public static final char TOPIC_WILDCARDS_ONE = '+';
public static final char TOPIC_WILDCARDS_MORE = '#';
private static final String MQTT_VERSION_KEY = "MQTT_V";
/**
* mqtt 版本
*
* @param ctx ChannelContext
* @return MqttVersion
*/
public static MqttVersion getMqttVersion(ChannelContext ctx) {
MqttVersion version = ctx.get(MQTT_VERSION_KEY);
if (version == null) {
return MqttVersion.MQTT_3_1_1;
}
return version;
}
protected static void setMqttVersion(ChannelContext ctx, MqttVersion version) {
ctx.set(MQTT_VERSION_KEY, version);
}
/**
* 判断是否 topic filter
*
* @param topicFilter topicFilter
* @return 是否 topic filter
*/
public static boolean isTopicFilter(String topicFilter) {
char[] topicFilterChars = topicFilter.toCharArray();
for (char ch : topicFilterChars) {
if (TOPIC_WILDCARDS_ONE == ch || TOPIC_WILDCARDS_MORE == ch) {
return true;
}
}
return false;
}
/**
* 是否校验过的 topicName
*
* @param topicName topicName
* @return 是否校验过的 topicName
*/
public static boolean isValidPublishTopicName(String topicName) {
// publish topic name must not contain any wildcard
return !isTopicFilter(topicName);
}
protected static boolean isValidClientId(MqttVersion mqttVersion, int maxClientIdLength, String clientId) {
if (clientId == null) {
return false;
}
switch (mqttVersion) {
case MQTT_3_1:
return clientId.length() >= MIN_CLIENT_ID_LENGTH && clientId.length() <= maxClientIdLength;
case MQTT_3_1_1:
case MQTT_5:
// In 3.1.3.1 Client Identifier of MQTT 3.1.1 and 5.0 specifications, The Server MAY allow ClientId’s
// that contain more than 23 encoded bytes. And, The Server MAY allow zero-length ClientId.
return true;
default:
throw new IllegalArgumentException(mqttVersion + " is unknown mqtt version");
}
}
protected static MqttFixedHeader validateFixedHeader(ChannelContext ctx, MqttFixedHeader mqttFixedHeader) {
switch (mqttFixedHeader.messageType()) {
case PUBREL:
case SUBSCRIBE:
case UNSUBSCRIBE:
if (MqttQoS.QOS1 != mqttFixedHeader.qosLevel()) {
throw new DecoderException(mqttFixedHeader.messageType().name() + " message must have QoS 1");
}
return mqttFixedHeader;
case AUTH:
if (MqttVersion.MQTT_5 != MqttCodecUtil.getMqttVersion(ctx)) {
throw new DecoderException("AUTH message requires at least MQTT 5");
}
return mqttFixedHeader;
default:
return mqttFixedHeader;
}
}
protected static MqttFixedHeader resetUnusedFields(MqttFixedHeader mqttFixedHeader) {
switch (mqttFixedHeader.messageType()) {
case CONNECT:
case CONNACK:
case PUBACK:
case PUBREC:
case PUBCOMP:
case SUBACK:
case UNSUBACK:
case PINGREQ:
case PINGRESP:
case DISCONNECT:
if (mqttFixedHeader.isDup() ||
MqttQoS.QOS0 != mqttFixedHeader.qosLevel() ||
mqttFixedHeader.isRetain()) {
return new MqttFixedHeader(
mqttFixedHeader.messageType(),
false,
MqttQoS.QOS0,
false,
mqttFixedHeader.remainingLength());
}
return mqttFixedHeader;
case PUBREL:
case SUBSCRIBE:
case UNSUBSCRIBE:
if (mqttFixedHeader.isRetain()) {
return new MqttFixedHeader(
mqttFixedHeader.messageType(),
mqttFixedHeader.isDup(),
mqttFixedHeader.qosLevel(),
false,
mqttFixedHeader.remainingLength());
}
return mqttFixedHeader;
default:
return mqttFixedHeader;
}
}
private MqttCodecUtil() {
}
}