Netty+SpringBoot+FastDFS+Html5实现聊天App(五)

Shimmer

Netty+SpringBoot+FastDFS+Html5实现聊天App,项目介绍

Netty+SpringBoot+FastDFS+Html5实现聊天App,项目github链接

本章完整代码链接

本章主要讲的是聊天App_PigChat中关于聊天功能的实现。

移除方法与处理异常方法的重写

在ChatHandler中重写其移除channel的方法handlerRemoved,以及处理异常的方法exceptionCaught。

    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        
        String channelId = ctx.channel().id().asShortText();
        System.out.println("客户端被移除,channelId为:" + channelId);
        
        // 当触发handlerRemoved,ChannelGroup会自动移除对应客户端的channel
        users.remove(ctx.channel());
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        // 发生异常之后关闭连接(关闭channel),随后从ChannelGroup中移除
        ctx.channel().close();
        users.remove(ctx.channel());
    }

定义消息的实体类

public class ChatMsg implements Serializable {

    private static final long serialVersionUID = 3611169682695799175L;
    
    private String senderId;        // 发送者的用户id    
    private String receiverId;        // 接受者的用户id
    private String msg;                // 聊天内容
    private String msgId;            // 用于消息的签收
    
    public String getSenderId() {
        return senderId;
    }
    public void setSenderId(String senderId) {
        this.senderId = senderId;
    }
    public String getReceiverId() {
        return receiverId;
    }
    public void setReceiverId(String receiverId) {
        this.receiverId = receiverId;
    }
    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    public String getMsgId() {
        return msgId;
    }
    public void setMsgId(String msgId) {
        this.msgId = msgId;
    }
    
}

对实体类再做一层包装

public class DataContent implements Serializable {

    private static final long serialVersionUID = 8021381444738260454L;

    private Integer action;        // 动作类型
    private ChatMsg chatMsg;    // 用户的聊天内容entity
    private String extand;        // 扩展字段
    
    public Integer getAction() {
        return action;
    }
    public void setAction(Integer action) {
        this.action = action;
    }
    public ChatMsg getChatMsg() {
        return chatMsg;
    }
    public void setChatMsg(ChatMsg chatMsg) {
        this.chatMsg = chatMsg;
    }
    public String getExtand() {
        return extand;
    }
    public void setExtand(String extand) {
        this.extand = extand;
    }
}

定义发送消息的动作的枚举类型

public enum MsgActionEnum {
    
    CONNECT(1, "第一次(或重连)初始化连接"),
    CHAT(2, "聊天消息"),    
    SIGNED(3, "消息签收"),
    KEEPALIVE(4, "客户端保持心跳"),
    PULL_FRIEND(5, "拉取好友");
    
    public final Integer type;
    public final String content;
    
    MsgActionEnum(Integer type, String content){
        this.type = type;
        this.content = content;
    }
    
    public Integer getType() {
        return type;
    }  
}



定义记录用户与channel关系的类

/**
 * @Description: 用户id和channel的关联关系处理
 */
public class UserChannelRel {

    private static HashMap<String, Channel> manager = new HashMap<>();

    public static void put(String senderId, Channel channel) {
        manager.put(senderId, channel);
    }
    
    public static Channel get(String senderId) {
        return manager.get(senderId);
    }
    
    public static void output() {
        for (HashMap.Entry<String, Channel> entry : manager.entrySet()) {
            System.out.println("UserId: " + entry.getKey() 
                            + ", ChannelId: " + entry.getValue().id().asLongText());
        }
    }
}

接受与处理消息方法的重写

重写ChatHandler读取消息的channelRead0方法。

具体步骤如下:

(1)获取客户端发来的消息;

(2)判断消息类型,根据不同的类型来处理不同的业务;

(2.1)当websocket 第一次open的时候,初始化channel,把用的channel和userid关联起来;

(2.2)聊天类型的消息,把聊天记录保存到数据库,同时标记消息的签收状态[未签收];
然后实现消息的发送,首先从全局用户Channel关系中获取接受方的channel,然后当receiverChannel不为空的时候,从ChannelGroup去查找对应的channel是否存在,若用户在线,则使用writeAndFlush方法向其发送消息;

(2.3)签收消息类型,针对具体的消息进行签收,修改数据库中对应消息的签收状态[已签收];

(2.4)心跳类型的消息

    // 用于记录和管理所有客户端的channle
    public static ChannelGroup users = 
            new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
    
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) 
            throws Exception {
        System.out.println("read..........");
        // 获取客户端传输过来的消息
        String content = msg.text();
        
        Channel currentChannel = ctx.channel();

        // 1. 获取客户端发来的消息
        DataContent dataContent = JsonUtils.jsonToPojo(content, DataContent.class);
        Integer action = dataContent.getAction();
        // 2. 判断消息类型,根据不同的类型来处理不同的业务

        if (action == MsgActionEnum.CONNECT.type) {
            //     2.1  当websocket 第一次open的时候,初始化channel,把用的channel和userid关联起来
            String senderId = dataContent.getChatMsg().getSenderId();
            UserChannelRel.put(senderId, currentChannel);
            
            // 测试
            for (Channel c : users) {
                System.out.println(c.id().asLongText());
            }
            UserChannelRel.output();
        } else if (action == MsgActionEnum.CHAT.type) {
            //  2.2  聊天类型的消息,把聊天记录保存到数据库,同时标记消息的签收状态[未签收]
            ChatMsg chatMsg = dataContent.getChatMsg();
            String msgText = chatMsg.getMsg();
            String receiverId = chatMsg.getReceiverId();
            String senderId = chatMsg.getSenderId();
            
            // 保存消息到数据库,并且标记为 未签收
            UserService userService = (UserService)SpringUtil.getBean("userServiceImpl");
            String msgId = userService.saveMsg(chatMsg);
            chatMsg.setMsgId(msgId);
            
            DataContent dataContentMsg = new DataContent();
            dataContentMsg.setChatMsg(chatMsg);
            
            // 发送消息
            // 从全局用户Channel关系中获取接受方的channel
            Channel receiverChannel = UserChannelRel.get(receiverId);
            if (receiverChannel == null) {
                // TODO channel为空代表用户离线,推送消息(JPush,个推,小米推送)
            } else {
                // 当receiverChannel不为空的时候,从ChannelGroup去查找对应的channel是否存在
                Channel findChannel = users.find(receiverChannel.id());
                if (findChannel != null) {
                    // 用户在线
                    receiverChannel.writeAndFlush(
                            new TextWebSocketFrame(
                                    JsonUtils.objectToJson(dataContentMsg)));
                } else {
                    // 用户离线 TODO 推送消息
                }
            }
            
        } else if (action == MsgActionEnum.SIGNED.type) {
            //  2.3  签收消息类型,针对具体的消息进行签收,修改数据库中对应消息的签收状态[已签收]
            UserService userService = (UserService)SpringUtil.getBean("userServiceImpl");
            // 扩展字段在signed类型的消息中,代表需要去签收的消息id,逗号间隔
            String msgIdsStr = dataContent.getExtand();
            String msgIds[] = msgIdsStr.split(",");
            
            List<String> msgIdList = new ArrayList<>();
            for (String mid : msgIds) {
                if (StringUtils.isNotBlank(mid)) {
                    msgIdList.add(mid);
                }
            }
            
            System.out.println(msgIdList.toString());
            
            if (msgIdList != null && !msgIdList.isEmpty() && msgIdList.size() > 0) {
                // 批量签收
                userService.updateMsgSigned(msgIdList);
            }
            
        } else if (action == MsgActionEnum.KEEPALIVE.type) {
            //  2.4  心跳类型的消息
            System.out.println("收到来自channel为[" + currentChannel + "]的心跳包...");
        }
    }
    

获取未签收的消息列表的接口

在controller中添加获取未签收的消息列表的接口getUnReadMsgList。

    /**
     * 
     * @Description: 用户手机端获取未签收的消息列表
     */
    @PostMapping("/getUnReadMsgList")
    public IMoocJSONResult getUnReadMsgList(String acceptUserId) {
        // 0. userId 判断不能为空
        if (StringUtils.isBlank(acceptUserId)) {
            return IMoocJSONResult.errorMsg("");
        }
        
        // 查询列表
        List<com.imooc.pojo.ChatMsg> unreadMsgList = userService.getUnReadMsgList(acceptUserId);
        
        return IMoocJSONResult.ok(unreadMsgList);
    }

测试

在这里插入图片描述

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