com.mobaijun.websocket.handler.CustomWebSocketHandler Maven / Gradle / Ivy
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/*
* Copyright (C) 2022 [www.mobaijun.com]
*
* Licensed 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 com.mobaijun.websocket.handler;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.json.JsonReadFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mobaijun.websocket.exception.ErrorJsonMessageException;
import com.mobaijun.websocket.hodler.JsonMessageHandlerHolder;
import com.mobaijun.websocket.message.JsonWebSocketMessage;
import io.micrometer.common.lang.NonNull;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
/**
* Description: 自定义 WebSocket 消息处理器
* Author: [mobaijun]
* Date: [2024/8/23 9:27]
* IntelliJ IDEA Version: [IntelliJ IDEA 2023.1.4]
*/
@Slf4j
public class CustomWebSocketHandler extends TextWebSocketHandler {
/**
* 消息解析器，用于解析 JSON 消息
*/
private static final ObjectMapper MAPPER = new ObjectMapper();
static {
// 启用对未转义控制字符的处理，避免解析 JSON 时因转义问题抛出异常
MAPPER.enable(JsonReadFeature.ALLOW_UNESCAPED_CONTROL_CHARS.mappedFeature());
}
/**
* 普通文本消息处理器，如果解析 JSON 失败，则使用该处理器处理
*/
private PlanTextMessageHandler planTextMessageHandler;
/**
* 构造函数注入 PlanTextMessageHandler 实例
*/
public CustomWebSocketHandler() {
}
/**
* 构造函数注入 PlanTextMessageHandler 实例
*
* @param planTextMessageHandler 普通文本消息处理器
*/
public CustomWebSocketHandler(PlanTextMessageHandler planTextMessageHandler) {
this.planTextMessageHandler = planTextMessageHandler;
}
/**
* 处理 WebSocket 文本消息
*
* 根据消息的内容决定是进行 JSON 处理还是回退到普通文本处理。
* 如果 JSON 处理失败，将使用 PlanTextMessageHandler 处理普通文本消息。
*
* @param session 当前 WebSocket 会话
* @param message 接收到的文本消息
*/
@Override
public void handleTextMessage(@NonNull WebSocketSession session, TextMessage message) {
// 空消息不处理
if (message.getPayloadLength() == 0) {
return;
}
// 获取消息载荷
String payload = message.getPayload();
try {
// 尝试使用 JSON 处理
handleWithJson(session, payload);
} catch (ErrorJsonMessageException ex) {
log.debug("消息载荷 [{}] 回退使用 PlanTextMessageHandler，原因：{}", payload, ex.getMessage());
// 处理 JSON 异常后，使用 PlanTextMessageHandler 处理普通文本消息
if (this.planTextMessageHandler != null) {
this.planTextMessageHandler.handle(session, payload);
} else {
log.error("[handleTextMessage] 普通文本消息（{}）没有对应的消息处理器", payload);
}
}
}
/**
* 使用 JSON 处理消息
*
* 解析消息载荷，检查其格式，并调用相应的消息处理器。
*
* @param session 当前 WebSocket 会话
* @param payload 消息载荷
*/
private void handleWithJson(WebSocketSession session, String payload) {
// 消息类型必有一个属性 type，先解析以获取该属性
JsonNode jsonNode;
try {
jsonNode = MAPPER.readTree(payload);
} catch (JsonProcessingException e) {
throw new ErrorJsonMessageException("json 解析异常");
}
// 确保消息类型是 object 类型
if (!jsonNode.isObject()) {
throw new ErrorJsonMessageException("json 格式异常！非 object 类型！");
}
JsonNode typeNode = jsonNode.get(JsonWebSocketMessage.TYPE_FIELD);
String messageType = typeNode.asText();
if (messageType == null) {
throw new ErrorJsonMessageException("json 无 type 属性");
}
// 根据消息类型获取对应的消息处理器
JsonMessageHandler jsonMessageHandler = JsonMessageHandlerHolder.getHandler(messageType);
if (jsonMessageHandler == null) {
log.error("[handleTextMessage] 消息类型（{}）不存在对应的消息处理器", messageType);
return;
}
// 处理消息
Class messageClass = jsonMessageHandler.getMessageClass();
JsonWebSocketMessage websocketMessageJson;
try {
websocketMessageJson = MAPPER.treeToValue(jsonNode, messageClass);
} catch (JsonProcessingException e) {
throw new ErrorJsonMessageException("消息序列化异常，class " + messageClass);
}
jsonMessageHandler.handle(session, websocketMessageJson);
}
}