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第三章：Kafka，构建TB级异步消息系统
一、阻塞队列
BlockingQueue- 解决线程通信的问题。
- 阻塞方法：
put、take。
生产者消费者模式
- 生产者：产生数据的线程。
- 消费者：使用数据的线程。
实现类
ArrayBlockingQueueLinkedBlockingQueuePriorityBlockingQueue、SynchronousQueue、DelayQueue等。
1. 阻塞队列测试方法
在 test 中添加 BlockingQueueTests类，来表示阻塞队列的测试方法，代码如下：
public class BlockingQueueTests {
public static void main(String[] args) {
BlockingQueue queue = new ArrayBlockingQueue(10);
new Thread(new Producer(queue)).start();
new Thread(new Consumer(queue)).start();
new Thread(new Consumer(queue)).start();
new Thread(new Consumer(queue)).start();
}
}
class Producer implements Runnable{
private BlockingQueue<Integer> queue;
public Producer(BlockingQueue<Integer> queue) {
this.queue = queue;
}
@Override
public void run(){
try{
for(int i = 0; i < 20; i ++ ) {
Thread.sleep(20);
queue.put(i);
System.out.println(Thread.currentThread().getName()+"生产："+ queue.size());
}
}catch (Exception e){
e.printStackTrace();
}
}
}
class Consumer implements Runnable{
private BlockingQueue<Integer> queue;
public Consumer(BlockingQueue<Integer> queue) {
this.queue = queue;
}
@Override
public void run() {
try {
while (true){
Thread.sleep(new Random().nextInt(1000));
queue.take();
System.out.println(Thread.currentThread().getName()+"消费："+ queue.size());
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}2. 测试结果
Thread-0生产：1
Thread-0生产：2
Thread-0生产：3
Thread-0生产：4
Thread-0生产：5
Thread-0生产：6
Thread-0生产：7
Thread-0生产：8
Thread-0生产：9
Thread-0生产：10
Thread-3消费：9
Thread-0生产：10
Thread-1消费：9
Thread-0生产：10
Thread-2消费：9
Thread-0生产：10
Thread-3消费：9
Thread-0生产：10
Thread-1消费：9
Thread-0生产：10
Thread-2消费：9
Thread-0生产：10
Thread-1消费：9
Thread-0生产：10
Thread-1消费：9
Thread-0生产：10
Thread-3消费：9
Thread-0生产：10
Thread-1消费：9
Thread-0生产：10
Thread-1消费：9
Thread-1消费：8
Thread-2消费：7
Thread-1消费：6
Thread-2消费：5
Thread-1消费：4
Thread-3消费：3
Thread-3消费：2
Thread-2消费：1
Thread-3消费：0二、Kafka入门
Kafka简介
- Kafka是一个分布式的流媒体平台。
- 应用：消息系统、日志收集、用户行为追踪、流式处理。
Kafka特点
- 高吞吐量、消息持久化、高可靠性、高扩展性。
Kafka术语
Broker、ZookeeperTopic、Partition、OffsetLeader Replica、Follower Replica
1. Kafka下载
Kafka官网: https://kafka.apache.org/
2. Kafka安装与配置
下载Kafka的安装包后进行解压，就相当于安装成功了。
需要进行以下配置：修改 config包下的 zookeeper.properties:
修改 config包下的 server.properties:
3. Kafka的启动
首先在命令行中启动 Zookeeper:
C:\Users\Andrew> d:
D:\> cd d:\kafka_2.13-3.2.3
d:\kafka_2.13-3.2.3>bin\windows\zookeeper-server-start.bat config\zookeeper.properties启动成功后不关闭此窗口，重新打开一个新的命令窗口，用于启动 kafka：
C:\Users\Andrew> d:
D:\> cd d:\kafka_2.13-3.2.3
d:\kafka_2.13-3.2.3>bin\windows\kafka-server-start.bat config\server.properties注意： 当遇到“‘wmic’不是内部或外部命令，也不是可运行程序”。
在C盘下找到wbem文件夹，且里面包含WMIC.exe，将其添加到系统变量path中去。
比如我的路径是：C:\Windows\System32\wbem，在系统变量path中新建该路径。就可以正常启动Kafka了。
4. Kafka使用
- 创建主题
cd到 …\kafka_2.13-2.8.0\bin\windows这里，然后输入 kafka-topics.bat --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic test
创建服务器端口号为9092（Kafka默认端口号）的topic，指生产者发布消息存储的位置在该服务器上localhost:9092。--replication-factor 1 指1个副本。--partitions 1 指1个分区。--topic test 指该主题名为 test。
- 以生产者身份发送消息
输入：kafka-console-producer.bat --broker-list localhost:9092 --topic test
生产者身份打开服务器列表中为localhost:9092的服务器上的test主题。--broker-list 指服务器列表。
并且输入要发送的消息：
- 以消费者身份读取消息
新打开一个命令行窗口，且cd到…\kafka_2.13-2.8.0\bin\windows，并输入：kafka-console-consumer.bat --bootstrap-server localhost:9092 --topic test --from-beginning
可以看到生产者发送的消息。并且这个消息队列中可以实时传送消息。
比如在生产者的命令行中继续输入信息，很快在消费者这边也能得到消息。
三、Spring整合Kafka
引入依赖
- `spring-kafka`配置Kafka
- 配置
server、consumer
- 配置
访问Kafka
- 生产者:
kafkaTemplate.send(topic, data);- 消费者:
@KafkaListener(topics = {"test"}public void handleMessage(ConsumerRecord record) {}
1. 引入依赖
在 pom.xml 添加相关的依赖：
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
<version>2.8.6</version>
</dependency> 2. 配置Kafka
#KafkaProperties
spring.kafka.bootstrap-servers=localhost:9092
spring.kafka.consumer.group-id=test-consumer-group
spring.kafka.consumer.enable-auto-commit=true
spring.kafka.consumer.auto-commit-interval=30003. 测试
在 test 包下添加 KafkaTests 类，代码如下：
@RunWith(SpringRunner.class)
@SpringBootTest
@ContextConfiguration(classes = CommunityApplication.class)
public class KafkaTests {
@Autowired
private KafkaProducer kafkaProducer;
@Test
public void testKafka() {
kafkaProducer.sendMessage("test", "你好");
kafkaProducer.sendMessage("test", "在吗");
try {
Thread.sleep(1000 * 20);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
@Component
class KafkaProducer {
@Autowired
private KafkaTemplate kafkaTemplate;
public void sendMessage(String topic, String content) {
kafkaTemplate.send(topic, content);
}
}
@Component
class KafkaConsumer {
@KafkaListener(topics = {"test"})
public void handleMessage(ConsumerRecord record) {
System.out.println(record.value());
}
}
4. 测试结果
四、发送系统消息
触发事件
- 评论后，发布通知
- 点赞后，发布通知
- 关注后，发布通知
处理事件
- 封装事件对象
- 开发事件的生产者
- 开发事件的消费者
1. 实体类
在 entity 包中添加 Event 实体类，代码如下：
public class Event {
private String topic;
private int userId; //用户Id
private int entityType; //实体类型
private int entityId; //实体Id
private int entityUserId; //实体作者Id
private Map<String,Object> data = new HashMap<>();
public String getTopic() {
return topic;
}
public Event setTopic(String topic) {
this.topic = topic;
return this;
}
public int getUserId() {
return userId;
}
public Event setUserId(int userId) {
this.userId = userId;
return this;
}
public int getEntityType() {
return entityType;
}
public Event setEntityType(int entityType) {
this.entityType = entityType;
return this;
}
public int getEntityId() {
return entityId;
}
public Event setEntityId(int entityId) {
this.entityId = entityId;
return this;
}
public int getEntityUserId() {
return entityUserId;
}
public Event setEntityUserId(int entityUserId) {
this.entityUserId = entityUserId;
return this;
}
public Map<String, Object> getData() {
return data;
}
public Event setData(String key,Object value) {
this.data.put(key,value);
return this;
}
}
创建 event 包，添加 EventProducer 类 和 EventConsumer 类，代码如下：
@Component
public class EventProducer {
@Autowired
private KafkaTemplate kafkaTemplate;
//处理事件
public void fireEvent(Event event){
//将事件发布到指定的主题
kafkaTemplate.send(event.getTopic(), JSONObject.toJSONString(event));
}
}@Component
public class EventConsumer implements CommunityConstant {
private static final Logger logger = LoggerFactory.getLogger(EventConsumer.class);
@Autowired
private MessageService messageService;
@KafkaListener(topics = {TOPIC_COMMENT, TOPIC_LIKE, TOPIC_FOLLOW})
public void handleCommentMessage(ConsumerRecord record) {
if (record == null || record.value() == null) {
logger.error("消息的内容为空!");
return;
}
Event event = JSONObject.parseObject(record.value().toString(), Event.class);
if (event == null) {
logger.error("消息格式错误!");
return;
}
// 发送站内通知
Message message = new Message();
message.setFromId(SYSTEM_USER_ID);
message.setToId(event.getEntityUserId());
message.setConversationId(event.getTopic());
message.setCreateTime(new Date());
Map<String, Object> content = new HashMap<>();
content.put("userId", event.getUserId());
content.put("entityType", event.getEntityType());
content.put("entityId", event.getEntityId());
//这里代码要再盘一下 额外数据，比如postId
if (!event.getData().isEmpty()) {
for (Map.Entry<String, Object> entry : event.getData().entrySet()) {
content.put(entry.getKey(), entry.getValue());
}
}
message.setContent(JSONObject.toJSONString(content));
messageService.addMessage(message);
}
}
2. util包
在 CommunityConstant 类中添加新的字段，代码如下：
public interface CommunityConstant {
/**
* 激活成功
*/
int ACTIVATION_SUCCESS = 0;
/**
* 重复激活
*/
int ACTIVATION_REPEAT = 1;
/**
* 激活失败
*/
int ACTIVATION_FAILURE = 2;
/**
* 默认状态的登录凭证的超时时间
*/
int DEFAULT_EXPIRED_SECONDS = 3600 * 12;
/**
* 记住状态的登录凭证超时时间
*/
int REMEMBER_EXPIRED_SECONDS = 3600 * 24 * 100;
/**
* 实体类型: 帖子
*/
int ENTITY_TYPE_POST = 1;
/**
* 实体类型: 评论
*/
int ENTITY_TYPE_COMMENT = 2;
/**
* 实体类型：用户
*/
int ENTITY_TYPE_USER = 3;
/**
* 主题: 评论
*/
String TOPIC_COMMENT = "comment";
/**
* 主题: 点赞
*/
String TOPIC_LIKE = "like";
/**
* 主题: 关注
*/
String TOPIC_FOLLOW = "follow";
/**
* 系统用户ID
*/
int SYSTEM_USER_ID = 1;
}
3. dao层
CommentMapper类中添加 selectCommentById 方法，代码如下：
@Mapper
public interface CommentMapper {
List<Comment> selectCommentsByEntity(int entityType, int entityId, int offset, int limit);
int selectCountByEntity(int entityType, int entityId);
int insertComment(Comment comment);
Comment selectCommentById(int id);
}对应的 comment-mapper.xml代码如下：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.nowcoder.community.dao.CommentMapper">
<sql id="selectFields">
id, user_id, entity_type, entity_id, target_id, content, status, create_time
</sql>
<sql id="insertFields">
user_id, entity_type, entity_id, target_id, content, status, create_time
</sql>
<select id="selectCommentsByEntity" resultType="com.nowcoder.community.entity.Comment">
select <include refid="selectFields"></include>
from comment
where status = 0
and entity_type = #{entityType}
and entity_id = #{entityId}
order by create_time asc
limit #{offset}, #{limit}
</select>
<select id="selectCountByEntity" resultType="int">
select count(id)
from comment
where status = 0
and entity_type = #{entityType}
and entity_id = #{entityId}
</select>
<insert id="insertComment" parameterType="com.nowcoder.community.entity.Comment">
insert into comment(<include refid="insertFields"></include>)
values(#{userId},#{entityType},#{entityId},#{targetId},#{content},#{status},#{createTime})
</insert>
<select id = "selectCommentById" resultType="com.nowcoder.community.entity.Comment">
select <include refid="selectFields"></include>
from comment
where id = #{id}
</select>
</mapper>
4. service包
在 CommentService 类中添加 findCommentById 方法，代码如下：
@Service
public class CommentService implements CommunityConstant {
@Autowired
private CommentMapper commentMapper;
@Autowired
private SensitiveFilter sensitiveFilter;
@Autowired
private DiscussPostService discussPostService;
public List<Comment> findCommentsByEntity(int entityType, int entityId, int offset, int limit) {
return commentMapper.selectCommentsByEntity(entityType, entityId, offset, limit);
}
public int findCommentCount(int entityType, int entityId) {
return commentMapper.selectCountByEntity(entityType, entityId);
}
@Transactional(isolation = Isolation.READ_COMMITTED, propagation = Propagation.REQUIRED)
public int addComment(Comment comment) {
if (comment == null) {
throw new IllegalArgumentException("参数不能为空！");
}
// 添加评论
comment.setContent(HtmlUtils.htmlEscape(comment.getContent()));
comment.setContent(sensitiveFilter.filter(comment.getContent()));
int rows = commentMapper.insertComment(comment);
// 更新帖子评论数量
if (comment.getEntityType() == ENTITY_TYPE_POST) {
int count = commentMapper.selectCountByEntity(comment.getEntityType(), comment.getEntityId());
discussPostService.updateCommentCount(comment.getEntityId(), count);
}
return rows;
}
public Comment findCommentById(int id) {
return commentMapper.selectCommentById(id);
}
}
## 5.controller层
在 commentcontroller 类中添加触发评论事件，代码如下：
@Controller
@RequestMapping("/comment")
public class CommentController implements CommunityConstant {
@Autowired
private CommentService commentService;
@Autowired
private HostHolder hostHolder;
@Autowired
private EventProducer eventProducer;
@Autowired
private DiscussPostService discussPostService;
@RequestMapping(value = "/add/{discussPostId}", method = RequestMethod.POST)
public String addComment(@PathVariable("discussPostId") int discussPostId, Comment comment) {
comment.setUserId(hostHolder.getUser().getId());
comment.setStatus(0);
comment.setCreateTime(new Date());
commentService.addComment(comment);
// 触发评论事件
Event event = new Event()
.setTopic(TOPIC_COMMENT)
.setUserId(hostHolder.getUser().getId())
.setEntityType(comment.getEntityType())
.setEntityId(comment.getEntityId())
.setData("postId", discussPostId);
if (comment.getEntityType() == ENTITY_TYPE_POST) {
DiscussPost target = discussPostService.findDiscussPostById(comment.getEntityId());
event.setEntityUserId(target.getUserId());
} else if (comment.getEntityType() == ENTITY_TYPE_COMMENT) {
Comment target = commentService.findCommentById(comment.getEntityId());
event.setEntityUserId(target.getUserId());
}
eventProducer.fireEvent(event);
return "redirect:/discuss/detail/" + discussPostId;
}
}
在 likecontroller 类中添加触发点赞事件，代码如下：
@Controller
public class LikeController implements CommunityConstant {
@Autowired
private LikeService likeService;
@Autowired
private HostHolder hostHolder;
@Autowired
private EventProducer eventProducer;
@RequestMapping(path = "/like", method = RequestMethod.POST)
@ResponseBody
public String like(int entityType, int entityId, int entityUserId, int postId) {
User user = hostHolder.getUser();
// 点赞
likeService.like(user.getId(), entityType, entityId, entityUserId);
// 数量
long likeCount = likeService.findEntityLikeCount(entityType, entityId);
// 状态
int likeStatus = likeService.findEntityLikeStatus(user.getId(), entityType, entityId);
// 返回的结果
Map<String, Object> map = new HashMap<>();
map.put("likeCount", likeCount);
map.put("likeStatus", likeStatus);
// 触发点赞事件
if (likeStatus == 1) {
Event event = new Event()
.setTopic(TOPIC_LIKE)
.setUserId(hostHolder.getUser().getId())
.setEntityType(entityType)
.setEntityId(entityId)
.setEntityUserId(entityUserId)
.setData("postId", postId); //postId对于点赞的是帖子而言，这个数据是冗余的
eventProducer.fireEvent(event);
}
return CommunityUtil.getJSONString(0, null, map);
}
}在 followeController 中添加触发关注事件，代码如下：
@Controller
public class FollowController implements CommunityConstant {
@Autowired
private FollowService followService;
@Autowired
private HostHolder hostHolder;
@Autowired
private UserService userService;
@Autowired
private EventProducer eventProducer;
@RequestMapping(path = "/follow", method = RequestMethod.POST)
@ResponseBody
public String follow(int entityType, int entityId) {
User user = hostHolder.getUser();
followService.follow(user.getId(), entityType, entityId);
// 触发关注事件
Event event = new Event()
.setTopic(TOPIC_FOLLOW)
.setUserId(hostHolder.getUser().getId())
.setEntityType(entityType)
.setEntityId(entityId)
.setEntityUserId(entityId);
eventProducer.fireEvent(event);
return CommunityUtil.getJSONString(0, "已关注！");
}
@RequestMapping(path = "/unfollow", method = RequestMethod.POST)
@ResponseBody
public String unfollow(int entityType, int entityId) {
User user = hostHolder.getUser();
followService.unfollow(user.getId(), entityType, entityId);
return CommunityUtil.getJSONString(0, "已取消关注!");
}
@RequestMapping(path = "/followees/{userId}", method = RequestMethod.GET)
public String getFollowees(@PathVariable("userId") int userId, Page page, Model model) {
User user = userService.findUserById(userId);
if (user == null) {
throw new RuntimeException("该用户不存在!");
}
model.addAttribute("user", user);
page.setLimit(5);
page.setPath("/followees/" + userId);
page.setRows((int) followService.findFolloweeCount(userId, ENTITY_TYPE_USER));
List<Map<String, Object>> userList = followService.findFollowees(userId, page.getOffset(), page.getLimit());
if (userList != null) {
for (Map<String, Object> map : userList) {
User u = (User) map.get("user");
map.put("hasFollowed", hasFollowed(u.getId()));
}
}
model.addAttribute("users", userList);
return "/site/followee";
}
@RequestMapping(path = "/followers/{userId}", method = RequestMethod.GET)
public String getFollowers(@PathVariable("userId") int userId, Page page, Model model) {
User user = userService.findUserById(userId);
if (user == null) {
throw new RuntimeException("该用户不存在!");
}
model.addAttribute("user", user);
page.setLimit(5);
page.setPath("/followers/" + userId);
page.setRows((int) followService.findFollowerCount(ENTITY_TYPE_USER, userId));
List<Map<String, Object>> userList = followService.findFollowers(userId, page.getOffset(), page.getLimit());
if (userList != null) {
for (Map<String, Object> map : userList) {
User u = (User) map.get("user");
map.put("hasFollowed", hasFollowed(u.getId()));
}
}
model.addAttribute("users", userList);
return "/site/follower";
}
private boolean hasFollowed(int userId) {
if (hostHolder.getUser() == null) {
return false;
}
return followService.hasFollowed(hostHolder.getUser().getId(), ENTITY_TYPE_USER, userId);
}
}
6. view层
对 discudd-detail.html 中的like 方法进行重构。discuss.js：
function like(btn, entityType, entityId, entityUserId, postId) {
$.post(
CONTEXT_PATH + "/like",
{"entityType":entityType,"entityId":entityId,"entityUserId":entityUserId,"postId":postId},
function(data) {
data = $.parseJSON(data);
if(data.code == 0) {
$(btn).children("i").text(data.likeCount);
$(btn).children("b").text(data.likeStatus==1?'已赞':"赞");
} else {
alert(data.msg);
}
}
);
} 
五、显示系统通知
通知列表
- 显示评论、点赞、关注三种类型的通知
通知详情
- 分页显示某一类主题所包含的通知
未读消息
- 在页面头部显示所有的未读消息数量
1. dao层
在 MessageMapper 类中添加 selectLatestNotice、selectNoticeCount、selectNoticeUnreadCount、selectNotices 方法，代码如下：
@Mapper
public interface MessageMapper {
// 查询当前用户的会话列表,针对每个会话只返回一条最新的私信.
List<Message> selectConversations(int userId, int offset, int limit);
// 查询当前用户的会话数量.
int selectConversationCount(int userId);
// 查询某个会话所包含的私信列表.
List<Message> selectLetters(String conversationId, int offset, int limit);
// 查询某个会话所包含的私信数量.
int selectLetterCount(String conversationId);
// 查询未读私信的数量
int selectLetterUnreadCount(int userId, String conversationId);
// 新增消息
int insertMessage(Message message);
// 修改消息的状态
int updateStatus(List<Integer> ids, int status);
// 查询某个主题下最新的通知
Message selectLatestNotice(int userId, String topic);
// 查询某个主题所包含的通知数量
int selectNoticeCount(int userId, String topic);
// 查询未读的通知的数量
int selectNoticeUnreadCount(int userId, String topic);
// 查询某个主题所包含的通知列表
List<Message> selectNotices(int userId, String topic, int offset, int limit);
}
对应的 message-mapper.xml 代码如下：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gerrard.community.dao.MessageMapper">
<sql id="selectFields">
id, from_id, to_id, conversation_id, content, status, create_time
</sql>
<sql id="insertFields">
from_id, to_id, conversation_id, content, status, create_time
</sql>
<select id="selectConversations" resultType="Message">
select <include refid="selectFields"></include>
from message
where id in (
select max(id) from message
where status != 2
and from_id != 1
and (from_id = #{userId} or to_id = #{userId})
group by conversation_id
)
order by id desc
limit #{offset}, #{limit}
</select>
<select id="selectConversationCount" resultType="int">
select count(m.maxid) from (
select max(id) as maxid from message
where status != 2
and from_id != 1
and (from_id = #{userId} or to_id = #{userId})
group by conversation_id
) as m
</select>
<select id="selectLetters" resultType="Message">
select <include refid="selectFields"></include>
from message
where status != 2
and from_id != 1
and conversation_id = #{conversationId}
order by id desc
limit #{offset}, #{limit}
</select>
<select id="selectLetterCount" resultType="int">
select count(id)
from message
where status != 2
and from_id != 1
and conversation_id = #{conversationId}
</select>
<select id="selectLetterUnreadCount" resultType="int">
select count(id)
from message
where status = 0
and from_id != 1
and to_id = #{userId}
<if test="conversationId!=null">
and conversation_id = #{conversationId}
</if>
</select>
<insert id="insertMessage" parameterType="Message" keyProperty="id">
insert into message(<include refid="insertFields"></include>)
values(#{fromId},#{toId},#{conversationId},#{content},#{status},#{createTime})
</insert>
<update id="updateStatus">
update message set status = #{status}
where id in
<foreach collection="ids" item="id" open="(" separator="," close=")">
#{id}
</foreach>
</update>
<select id="selectLatestNotice" resultType="Message">
select <include refid="selectFields"></include>
from message
where id in (
select max(id) from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
)
</select>
<select id="selectNoticeCount" resultType="int">
select count(id) from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
</select>
<select id="selectNoticeUnreadCount" resultType="int">
select count(id) from message
where status = 0
and from_id = 1
and to_id = #{userId}
<if test="topic!=null">
and conversation_id = #{topic}
</if>
</select>
<select id="selectNotices" resultType="Message">
select <include refid="selectFields"></include>
from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
order by create_time desc
limit #{offset}, #{limit}
</select>
</mapper>
2. service层
在 MessageService 类中添加 findLatesNotice、findNoticeCount 、findNoticeUnreadCount、findNotices方法，代码如下：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gerrard.community.dao.MessageMapper">
<sql id="selectFields">
id, from_id, to_id, conversation_id, content, status, create_time
</sql>
<sql id="insertFields">
from_id, to_id, conversation_id, content, status, create_time
</sql>
<select id="selectConversations" resultType="Message">
select <include refid="selectFields"></include>
from message
where id in (
select max(id) from message
where status != 2
and from_id != 1
and (from_id = #{userId} or to_id = #{userId})
group by conversation_id
)
order by id desc
limit #{offset}, #{limit}
</select>
<select id="selectConversationCount" resultType="int">
select count(m.maxid) from (
select max(id) as maxid from message
where status != 2
and from_id != 1
and (from_id = #{userId} or to_id = #{userId})
group by conversation_id
) as m
</select>
<select id="selectLetters" resultType="Message">
select <include refid="selectFields"></include>
from message
where status != 2
and from_id != 1
and conversation_id = #{conversationId}
order by id desc
limit #{offset}, #{limit}
</select>
<select id="selectLetterCount" resultType="int">
select count(id)
from message
where status != 2
and from_id != 1
and conversation_id = #{conversationId}
</select>
<select id="selectLetterUnreadCount" resultType="int">
select count(id)
from message
where status = 0
and from_id != 1
and to_id = #{userId}
<if test="conversationId!=null">
and conversation_id = #{conversationId}
</if>
</select>
<insert id="insertMessage" parameterType="Message" keyProperty="id">
insert into message(<include refid="insertFields"></include>)
values(#{fromId},#{toId},#{conversationId},#{content},#{status},#{createTime})
</insert>
<update id="updateStatus">
update message set status = #{status}
where id in
<foreach collection="ids" item="id" open="(" separator="," close=")">
#{id}
</foreach>
</update>
<select id="selectLatestNotice" resultType="Message">
select <include refid="selectFields"></include>
from message
where id in (
select max(id) from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
)
</select>
<select id="selectNoticeCount" resultType="int">
select count(id) from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
</select>
<select id="selectNoticeUnreadCount" resultType="int">
select count(id) from message
where status = 0
and from_id = 1
and to_id = #{userId}
<if test="topic!=null">
and conversation_id = #{topic}
</if>
</select>
<select id="selectNotices" resultType="Message">
select <include refid="selectFields"></include>
from message
where status != 2
and from_id = 1
and to_id = #{userId}
and conversation_id = #{topic}
order by create_time desc
limit #{offset}, #{limit}
</select>
</mapper>
3. controller层
在 MessageController 类中添加 getNoticeList、getNoticerDetail 方法，代码如下：
@Controller
public class MessageController implements CommunityConstant {
@Autowired
private MessageService messageService;
@Autowired
private HostHolder hostHolder;
@Autowired
private UserService userService;
// 私信列表
@RequestMapping(path = "/letter/list", method = RequestMethod.GET)
public String getLetterList(Model model, Page page) {
User user = hostHolder.getUser();
// 分页信息
page.setLimit(5);
page.setPath("/letter/list");
page.setRows(messageService.findConversationCount(user.getId()));
// 会话列表
List<Message> conversationList = messageService.findConversations(
user.getId(), page.getOffset(), page.getLimit());
List<Map<String, Object>> conversations = new ArrayList<>();
if (conversationList != null) {
for (Message message : conversationList) {
Map<String, Object> map = new HashMap<>();
map.put("conversation", message);
map.put("letterCount", messageService.findLetterCount(message.getConversationId()));
map.put("unreadCount", messageService.findLetterUnreadCount(user.getId(), message.getConversationId()));
int targetId = user.getId() == message.getFromId() ? message.getToId() : message.getFromId();
map.put("target", userService.findUserById(targetId));
conversations.add(map);
}
}
model.addAttribute("conversations", conversations);
// 查询未读消息数量
int letterUnreadCount = messageService.findLetterUnreadCount(user.getId(), null);
model.addAttribute("letterUnreadCount", letterUnreadCount);
int noticeUnreadCount = messageService.findNoticeUnreadCount(user.getId(), null);
model.addAttribute("noticeUnreadCount", noticeUnreadCount);
return "/site/letter";
}
@RequestMapping(path = "/letter/detail/{conversationId}", method = RequestMethod.GET)
public String getLetterDetail(@PathVariable("conversationId") String conversationId, Page page, Model model) {
// 分页信息
page.setLimit(5);
page.setPath("/letter/detail/" + conversationId);
page.setRows(messageService.findLetterCount(conversationId));
// 私信列表
List<Message> letterList = messageService.findLetters(conversationId, page.getOffset(), page.getLimit());
List<Map<String, Object>> letters = new ArrayList<>();
if (letterList != null) {
for (Message message : letterList) {
Map<String, Object> map = new HashMap<>();
map.put("letter", message);
map.put("fromUser", userService.findUserById(message.getFromId()));
letters.add(map);
}
}
model.addAttribute("letters", letters);
// 私信目标
model.addAttribute("target", getLetterTarget(conversationId));
// 设置已读
List<Integer> ids = getLetterIds(letterList);
if (!ids.isEmpty()) {
messageService.readMessage(ids);
}
return "/site/letter-detail";
}
private User getLetterTarget(String conversationId) {
String[] ids = conversationId.split("_");
int id0 = Integer.parseInt(ids[0]);
int id1 = Integer.parseInt(ids[1]);
if (hostHolder.getUser().getId() == id0) {
return userService.findUserById(id1);
} else {
return userService.findUserById(id0);
}
}
private List<Integer> getLetterIds(List<Message> letterList) {
List<Integer> ids = new ArrayList<>();
if (letterList != null) {
for (Message message : letterList) {
if (hostHolder.getUser().getId() == message.getToId() && message.getStatus() == 0) {
ids.add(message.getId());
}
}
}
return ids;
}
@RequestMapping(path = "/letter/send", method = RequestMethod.POST)
@ResponseBody
public String sendLetter(String toName, String content) {
User target = userService.findUserByName(toName);
if (target == null) {
return CommunityUtil.getJSONString(1, "目标用户不存在!");
}
Message message = new Message();
message.setFromId(hostHolder.getUser().getId());
message.setToId(target.getId());
if (message.getFromId() < message.getToId()) {
message.setConversationId(message.getFromId() + "_" + message.getToId());
} else {
message.setConversationId(message.getToId() + "_" + message.getFromId());
}
message.setContent(content);
message.setCreateTime(new Date());
messageService.addMessage(message);
return CommunityUtil.getJSONString(0);
}
@RequestMapping(path = "/notice/list", method = RequestMethod.GET)
public String getNoticeList(Model model) {
User user = hostHolder.getUser();
// 查询评论类通知
Message message = messageService.findLatestNotice(user.getId(), TOPIC_COMMENT);
Map<String, Object> messageVO = new HashMap<>();
if (message != null) {
messageVO.put("message", message);
String content = HtmlUtils.htmlUnescape(message.getContent());
Map<String, Object> data = JSONObject.parseObject(content, HashMap.class);
messageVO.put("user", userService.findUserById((Integer) data.get("userId")));
messageVO.put("entityType", data.get("entityType"));
messageVO.put("entityId", data.get("entityId"));
messageVO.put("postId", data.get("postId"));
int count = messageService.findNoticeCount(user.getId(), TOPIC_COMMENT);
messageVO.put("count", count);
int unread = messageService.findNoticeUnreadCount(user.getId(), TOPIC_COMMENT);
messageVO.put("unread", unread);
}
model.addAttribute("commentNotice", messageVO);
// 查询点赞类通知
message = messageService.findLatestNotice(user.getId(), TOPIC_LIKE);
messageVO = new HashMap<>();
if (message != null) {
messageVO.put("message", message);
String content = HtmlUtils.htmlUnescape(message.getContent());
Map<String, Object> data = JSONObject.parseObject(content, HashMap.class);
messageVO.put("user", userService.findUserById((Integer) data.get("userId")));
messageVO.put("entityType", data.get("entityType"));
messageVO.put("entityId", data.get("entityId"));
messageVO.put("postId", data.get("postId"));
int count = messageService.findNoticeCount(user.getId(), TOPIC_LIKE);
messageVO.put("count", count);
int unread = messageService.findNoticeUnreadCount(user.getId(), TOPIC_LIKE);
messageVO.put("unread", unread);
}
model.addAttribute("likeNotice", messageVO);
// 查询关注类通知
message = messageService.findLatestNotice(user.getId(), TOPIC_FOLLOW);
messageVO = new HashMap<>();
if (message != null) {
messageVO.put("message", message);
String content = HtmlUtils.htmlUnescape(message.getContent());
Map<String, Object> data = JSONObject.parseObject(content, HashMap.class);
messageVO.put("user", userService.findUserById((Integer) data.get("userId")));
messageVO.put("entityType", data.get("entityType"));
messageVO.put("entityId", data.get("entityId"));
int count = messageService.findNoticeCount(user.getId(), TOPIC_FOLLOW);
messageVO.put("count", count);
int unread = messageService.findNoticeUnreadCount(user.getId(), TOPIC_FOLLOW);
messageVO.put("unread", unread);
}
model.addAttribute("followNotice", messageVO);
// 查询未读消息数量
int letterUnreadCount = messageService.findLetterUnreadCount(user.getId(), null);
model.addAttribute("letterUnreadCount", letterUnreadCount);
int noticeUnreadCount = messageService.findNoticeUnreadCount(user.getId(), null);
model.addAttribute("noticeUnreadCount", noticeUnreadCount);
return "/site/notice";
}
@RequestMapping(path = "/notice/detail/{topic}", method = RequestMethod.GET)
public String getNoticeDetail(@PathVariable("topic") String topic, Page page, Model model) {
User user = hostHolder.getUser();
page.setLimit(5);
page.setPath("/notice/detail/" + topic);
page.setRows(messageService.findNoticeCount(user.getId(), topic));
List<Message> noticeList = messageService.findNotices(user.getId(), topic, page.getOffset(), page.getLimit());
List<Map<String, Object>> noticeVoList = new ArrayList<>();
if (noticeList != null) {
for (Message notice : noticeList) {
Map<String, Object> map = new HashMap<>();
// 通知
map.put("notice", notice);
// 内容
String content = HtmlUtils.htmlUnescape(notice.getContent());
Map<String, Object> data = JSONObject.parseObject(content, HashMap.class);
map.put("user", userService.findUserById((Integer) data.get("userId")));
map.put("entityType", data.get("entityType"));
map.put("entityId", data.get("entityId"));
map.put("postId", data.get("postId"));
// 通知作者
map.put("fromUser", userService.findUserById(notice.getFromId()));
noticeVoList.add(map);
}
}
model.addAttribute("notices", noticeVoList);
// 设置已读
List<Integer> ids = getLetterIds(noticeList);
if (!ids.isEmpty()) {
messageService.readMessage(ids);
}
return "/site/notice-detail";
}
}
旧版：新建 MessageInterceptor 类拦截器。
新版：在 LoginTicketinterceptor 中对 posthandle 方法进行修改，代码如下：
@Component
public class LoginTicketInterceptor implements HandlerInterceptor {
@Autowired
private UserService userService;
@Autowired
private HostHolder hostHolder;
@Autowired
private MessageService messageService;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//从cookie中获取凭证
String ticket= CookieUtil.getValue(request,"ticket");
if(ticket!=null){
//查询凭证
LoginTicket loginTicket=userService.findLoginTicket(ticket);
//检查凭证是否有效
//一般不会检测到过期，因为时间一到，cookie自动被销毁了？？？？？
if(loginTicket!=null && loginTicket.getStatus()==0 && loginTicket.getExpired().after(new Date())){
//根据凭证查询用户
User user=userService.findUserById(loginTicket.getUserId());
//在本次请求中持有用户
hostHolder.setUser(user);
//构建用户认证的结果，并存入SecurityContext，以便于Security进行授权
Authentication authentication=new UsernamePasswordAuthenticationToken(
user,user.getPassword(),userService.getAuthorities(user.getId()));
SecurityContextHolder.setContext(new SecurityContextImpl(authentication));
}
}
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
User user=hostHolder.getUser();
if(user!=null && modelAndView !=null){
int unReadLetterCount=messageService.findLetterUnreadCount(user.getId(),null);
int unReadNoticeCount=messageService.findNoticeUnreadCount(user.getId(),null);
modelAndView.addObject("loginUser",user);
modelAndView.addObject("messageUnRead",unReadLetterCount+unReadNoticeCount);
}
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
hostHolder.clear();
// SecurityContextHolder.clearContext();
}
}
4. view层
前端页面代码的修改在项目汇总中可进行查看。
5. 功能测试
5. 功能测试
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