手写MQ框架（二）-服务端实现

一、起航

书接上文->手写MQ框架（一）-准备启程

本着从无到有，从有到优的原则，所以计划先通过web实现功能，然后再优化改写为socket的形式。

1、关于技术选型

web框架使用了之前写的gmvc框架（手写MVC框架（一）-再出发），消息存储采用存在数据库的方式，使用的框架也是前段时间写的gdao（手写DAO框架（一）-从“1”开始 ）。

2、项目搭建

项目本来是单项目的形式，但是考虑到将服务端、客户端分开不是很友好，所以采用了maven父子模块的形式。

其中，父pom配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.shuimutong</groupId>
    <artifactId>gmq</artifactId>
    <version>${global.version}</version>
    <packaging>pom</packaging>
    <url>http://maven.apache.org</url>

    <modules>
        <module>gmq-server</module>
        <module>gmq-client</module>
    </modules>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <global.version>0.0.1-SNAPSHOT</global.version>
        <fastjson.version>1.2.60</fastjson.version>
        <gdao.version>2.0.0-SNAPSHOT</gdao.version>
        <gmvc.version>1.0.1-SNAPSHOT</gmvc.version>
        <gutil.version>0.0.2-SNAPSHOT</gutil.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>me.lovegao</groupId>
                <artifactId>gdao</artifactId>
                <version>${gdao.version}</version>
            </dependency>
            <dependency>
                <groupId>com.shuimutong</groupId>
                <artifactId>gmvc</artifactId>
                <version>${gmvc.version}</version>
            </dependency>
            <dependency>
                <groupId>com.shuimutong</groupId>
                <artifactId>gutil</artifactId>
                <version>${gutil.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>${fastjson.version}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.4</version>
            </dependency>
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>1.2.16</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
                <version>1.6.1</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
                <version>1.6.2</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <target>1.8</target>
                    <source>1.8</source>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

这次要说的mq服务端pom配置如下：

<?xml version="1.0"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.shuimutong</groupId>
        <artifactId>gmq</artifactId>
        <version>${global.version}</version>
    </parent>
    <groupId>com.shuimutong</groupId>
    <artifactId>gmq-server</artifactId>
    <packaging>war</packaging>
    <version>${global.version}</version>
    <name>gmq-server</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>me.lovegao</groupId>
            <artifactId>gdao</artifactId>
        </dependency>
        <dependency>
            <groupId>com.shuimutong</groupId>
            <artifactId>gmvc</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>javax.servlet</groupId>
                    <artifactId>javax.servlet-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
        </dependency>
    </dependencies>
    <build>
        <finalName>com.shuimutong.gmq_server</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <target>1.8</target>
                    <source>1.8</source>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

 项目依赖的gdao（https://gitee.com/simpleha/gdao.git）、gmvc（https://gitee.com/simpleha/gmvc.git）、gutil（https://gitee.com/simpleha/gutil.git）需要先clone到本地并编译到maven仓库。

二、接口梳理

1、SyncController

在发布消息或者订阅消息前，我们需要先新增topic。我这里把新增topic和后面的发布订阅消息分开了，主要是考虑到两个类被访问频率有差别，分开后有利于以后的针对优化。

具体实现如下：

package com.shuimutong.gmq.server.controller;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.fastjson.JSONObject;
import com.shuimutong.gmq.server.bean.enums.RequestParamEnum;
import com.shuimutong.gmq.server.bean.enums.ResponseCodeEnum;
import com.shuimutong.gmq.server.bean.vo.ResponseDataVo;
import com.shuimutong.gmq.server.bean.vo.UriDescVo;
import com.shuimutong.gmq.server.exception.ServiceException;
import com.shuimutong.gmq.server.service.SyncService;
import com.shuimutong.gmq.server.service.TopicService;
import com.shuimutong.gmvc.annotation.XAutowired;
import com.shuimutong.gmvc.annotation.XController;
import com.shuimutong.gmvc.annotation.XRequestMapping;
import com.shuimutong.gmvc.util.RequestResolveUtil;

/**
 * 非消息信息同步controller
 * @ClassName:  MessageController   
 * @Description:(这里用一句话描述这个类的作用)   
 * @author: 水木桶
 * @date:   2019年10月20日 下午9:45:47     
 * @Copyright: 2019 [水木桶]  All rights reserved.
 */
@XController
@XRequestMapping("/sync")
public class SyncController {
    private final static Logger log = LoggerFactory.getLogger(SyncController.class);
    @XAutowired
    private TopicService topicService;
    @XAutowired
    private SyncService syncService;

    /**
     * 获取uri说明
     * @param request
     * @param reponse
     */
    @XRequestMapping("/getPath")
    public void getPath(HttpServletRequest request, HttpServletResponse reponse) {
        List<UriDescVo> uriList = syncService.listUriDesc();
        ResponseDataVo responseData = new ResponseDataVo(ResponseCodeEnum.OK, uriList);
        RequestResolveUtil.returnJson(request, reponse, JSONObject.toJSONString(responseData));
    }
    
    /**
     * 新增topic
     * @param request
     * @param reponse
     */
    @XRequestMapping("/addTopic")
    public void addTopic(HttpServletRequest request, HttpServletResponse reponse) {
        ResponseDataVo responseData = null;
        String topic = request.getParameter(RequestParamEnum.TOPIC.getParamName());
        if(StringUtils.isBlank(topic)) {
            responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题为空");
        } else {
            try {
                boolean addState = topicService.addTopic(topic);
                if(addState) {
                    responseData = new ResponseDataVo(ResponseCodeEnum.OK, "添加成功");
                } else {
                    responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题已存在");
                }
            } catch (ServiceException e) {
                log.error("addTopicException," + topic, e);
                responseData = new ResponseDataVo(ResponseCodeEnum.SERVER_ERROR);
            }
        }
        RequestResolveUtil.returnJson(request, reponse, JSONObject.toJSONString(responseData));
    }
}

其中getPath()暂时没有用到，以后用到再讨论吧。

2、MessageController

消息的topic创建之后，就是消息的发布和订阅了。

具体实现如下：

package com.shuimutong.gmq.server.controller;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.fastjson.JSONObject;
import com.shuimutong.gmq.server.bean.SystemConstant;
import com.shuimutong.gmq.server.bean.dos.TopicDo;
import com.shuimutong.gmq.server.bean.enums.RequestParamEnum;
import com.shuimutong.gmq.server.bean.enums.ResponseCodeEnum;
import com.shuimutong.gmq.server.bean.vo.ResponseDataVo;
import com.shuimutong.gmq.server.exception.ServiceException;
import com.shuimutong.gmq.server.service.MessageService;
import com.shuimutong.gmq.server.service.TopicService;
import com.shuimutong.gmvc.annotation.XAutowired;
import com.shuimutong.gmvc.annotation.XController;
import com.shuimutong.gmvc.annotation.XRequestMapping;
import com.shuimutong.gmvc.util.RequestResolveUtil;
import com.shuimutong.guti.bean.TwoTuple;

/**
 * 发消息、收消息controller
 * @ClassName:  MessageController   
 * @Description:(这里用一句话描述这个类的作用)   
 * @author: 水木桶
 * @date:   2019年10月20日 下午9:45:47     
 * @Copyright: 2019 [水木桶]  All rights reserved.
 */
@XController
@XRequestMapping(SystemConstant.STR_URL_MESSAGE)
public class MessageController {
    private final static Logger log = LoggerFactory.getLogger(MessageController.class);
    @XAutowired
    private MessageService messageService;
    @XAutowired
    private TopicService topicService;
    

    /**
     * 获取消息
     * @param request
     * @param reponse
     */
    @XRequestMapping(SystemConstant.STR_URL_GET_MESSAGE)
    public void getMessage(HttpServletRequest request, HttpServletResponse reponse) {
        ResponseDataVo responseData = null;
        String topic = request.getParameter(RequestParamEnum.TOPIC.getParamName());
        String offsetStr = request.getParameter(RequestParamEnum.OFFSET.getParamName());
        String sizeStr = request.getParameter(RequestParamEnum.SIZE.getParamName());
        
        if(StringUtils.isBlank(topic) || !StringUtils.isNumeric(offsetStr) || !StringUtils.isNumeric(sizeStr)) {
            responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题为空或者数字非法");
        } else {
            int offset = Integer.parseInt(offsetStr);
            int size = Integer.parseInt(sizeStr);
            if(offset < 0 || size < 1) {
                responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "数字异常");
            } else {
                try {
                    TopicDo topicDo = topicService.findByTopic(topic);
                    if(topicDo == null) {
                        responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题不存在");
                    } else {
                        List<TwoTuple<Long, String>> list = messageService.listMessage(topic, offset, size);
                        responseData = new ResponseDataVo(ResponseCodeEnum.OK, list);
                    }
                } catch (ServiceException e) {
                    log.error("getMessageException", e);
                    responseData = new ResponseDataVo(ResponseCodeEnum.SERVER_ERROR);
                }
            }
        }
        RequestResolveUtil.returnJson(request, reponse, JSONObject.toJSONString(responseData));
    }
    
    
    /**
     * 生产方发送消息到服务端
     * @param request
     * @param reponse
     */
    @XRequestMapping(SystemConstant.STR_URL_SEND_MESSAGE)
    public void sendMessage(HttpServletRequest request, HttpServletResponse reponse) {
        ResponseDataVo responseData = null;
        String topic = request.getParameter(RequestParamEnum.TOPIC.getParamName());
        String message = request.getParameter(RequestParamEnum.MESSAGE.getParamName());
        if(StringUtils.isBlank(topic) || StringUtils.isBlank(message)) {
            responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题或者消息为空");
        } else {
            try {
                TopicDo topicDo = topicService.findByTopic(topic);
                if(topicDo == null) {
                    responseData = new ResponseDataVo(ResponseCodeEnum.PARAM_ERROR, "主题不存在");
                } else {
                    messageService.saveMessage(topic, message);
                    responseData = new ResponseDataVo(ResponseCodeEnum.OK);
                }
            } catch (ServiceException e) {
                log.error("sendMessageException", e);
                responseData = new ResponseDataVo(ResponseCodeEnum.SERVER_ERROR);
            }
        }
        RequestResolveUtil.returnJson(request, reponse, JSONObject.toJSONString(responseData));
    }
}

3、CacheController

设计的mq的消费形式是拉的形式。采用拉的形式，就需要客户端自己去计数，消费到哪了。

所以这里增加了这个缓存接口，提供kv存储的功能。数据存储在数据库里。

代码请移步到下文的gitee连接查看。

有了上面这几个接口，就可以实现简单的发布消息、订阅消息的功能了，当然是手动的方式获取。

三、相关表

既然为了分享，资料就得提供全。所以这里就列一下关联的数据库表结构。

1、主题表

CREATE TABLE `gmq_topic` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
  `topic` varchar(255) NOT NULL DEFAULT '' COMMENT '主题',
  `create_time` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp() COMMENT '创建时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uniq_idx_topic` (`topic`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COMMENT='gmq-主题表';

2、消息表

CREATE TABLE `gmq_message` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
  `topic` varchar(255) NOT NULL DEFAULT '' COMMENT '主题',
  `message_body` text NOT NULL COMMENT '消息内容',
  `create_time` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp() COMMENT '创建时间',
  PRIMARY KEY (`id`),
  KEY `idx_id_topic` (`id`,`topic`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COMMENT='存储的消息';

3、kv表

CREATE TABLE `gmq_message` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
  `topic` varchar(255) NOT NULL DEFAULT '' COMMENT '主题',
  `message_body` text NOT NULL COMMENT '消息内容',
  `create_time` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp() COMMENT '创建时间',
  PRIMARY KEY (`id`),
  KEY `idx_id_topic` (`id`,`topic`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COMMENT='存储的消息';

四、总结

主要功能就是上面些。回头看来也不算很多，但是具体实现过程中真是曲折重重，这其中一部分是框架的原因。

所以上篇博客到这篇博客中间，我不仅写完了这个项目，其实还顺便修复了框架使用中遇到的一些问题。比如bigint类型的数据查出来真的是BigDecimal，而不是long。

gmq项目主要包括两块，上面介绍的是服务端，接下来会介绍客户端。

最后，附上代码地址：https://gitee.com/simpleha/gmq.git

下一篇，客户端的实现->手写MQ框架（三）-客户端实现