• 站内信的实现
• 站内信
“站内信”主要实现站内用户的沟通，有两个基本功能。
一：点到点的消息传送。用户给用户发送站内信，管理员给用户发送站内信。
二：点到面的消息传送。管理员给用户（指定满足某一条件的用户群）群发消息
站内信的开发流程
1. Database Column
2. Model：模型定义，和数据库相匹配
3. DAO：数据读取
4. Service：服务包装
5. Controller：业务入口
6. Test
1. Database Column
private int id;
private int from_Id;
private int to_Id;
private String content;
private Date createdDate;
private int hasRead;
2. Model：模型定义，和数据库相匹配
package com.LG.model;
import java.util.Date;
/**
* @Author liguo
* @Description
* @Data 2018-09-06 14:21
*/
public class Message {
private int id;
private int fromId;
private int toId;
private String content;
private Date createdDate;
private int hasRead;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getFromId() {
return fromId;
}
public void setFromId(int fromId) {
this.fromId = fromId;
}
public int getToId() {
return toId;
}
public void setToId(int toId) {
this.toId = toId;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public Date getCreatedDate() {
return createdDate;
}
public void setCreatedDate(Date createdDate) {
this.createdDate = createdDate;
}
public int getHasRead() {
return hasRead;
}
public void setHasRead(int hasRead) {
this.hasRead = hasRead;
}
public String getConversationId() {
if (fromId < toId) {
return String.format("%d_%d", fromId, toId);
} else {
return String.format("%d_%d", toId, fromId);
}
}
public void setConversationId(String conversationId) {
String conversationId1 = conversationId;
}
}
3. DAO：数据读取
package com.LG.dao;
import com.LG.model.Message;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import java.util.List;
/**
* @Author liguo
* @Description
* @Data 2018-09-06 14:38
*/
@Mapper
public interface MessageDAO {
String TABLE_NAME = " message ";
String INSERT_FIELDS = " from_id, to_id, content, has_read, conversation_id, created_date ";
String SELECT_FIELDS = " id, " + INSERT_FIELDS;
@Insert({"insert into ", TABLE_NAME, "(", INSERT_FIELDS,
") values (#{fromId},#{toId},#{content},#{hasRead},#{conversationId},#{createdDate})"})
int addMessage(Message message);
@Select({"select ", SELECT_FIELDS, " from ", TABLE_NAME,
" where conversation_id=#{conversationId} order by created_date desc limit #{offset}, #{limit}"})
List<Message> getConversationDetail(@Param("conversationId") String conversationId,
@Param("offset") int offset,
@Param("limit") int limit);
@Select({"select ", INSERT_FIELDS, " , count(id) as id from ( select * from ", TABLE_NAME,
" where from_id=#{userId} or to_id=#{userId} order by created_date desc) tt group by conversation_id order by created_date desc limit #{offset}, #{limit}"})
//实现分页功能；offset是分的页数目 ，limit为每页显示的内容；
List <Message> getConversationList(@Param("userId") int userId,
@Param("offset") int offset,
@Param("limit") int limit);
@Select({"select count(id) from ", TABLE_NAME, " where has_read=0 and to_id=#{userId} and conversation_id=#{conversationId}"})
int getConversationUnreadCount(@Param("userId") int userId, @Param("conversationId") String conversationId);
}
4. Service：服务包装
5. Controller：业务入口
6. Test