spring-boot集成mybatis,用redis做缓存

网上有很多例子了,执行源码起码有3个,都是各种各样的小问题。

现在做了个小demo,实现spring-boot 用redis做缓存的实例,简单记录下思路,分享下源码。

缓存的实现,分担了数据库的压力,在CRUD中

C:需要同时更新redis和mysql中的数据。

R:看redis中 有无数据,有,就从缓存中取,没有就从数据库中取,同时更新缓存。

U:删除redis中的数据,并update数据库。

D:删除redis和mysql的数据。

1、基本步骤

  (1)redis安装  http://download.csdn.net/download/xsx531588644/9565831

  (2)配置pom.xml

  (3)添加工具类

  (4)添加项目启动扫描类

  (5)修改controller

2、实现

  (1)安装redis

                 有一个redis图形管理工具很好用RedisManager,可以一起装上。

      引入操作redis的客户端包jedis,见下方的总结。

  (2)配置pom.xml

    添加代码

  

<!-- 热部署 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        
        <!-- redis cache related.....start -->  
        <dependency>  
            <groupId>org.springframework.data</groupId>  
            <artifactId>spring-data-redis</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>redis.clients</groupId>  
            <artifactId>jedis</artifactId>  
        </dependency>

完整pom.xml代码

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.sun</groupId>
  <artifactId>spring-boot-test</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
      <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.1.RELEASE</version>
    </parent>
    
    <dependencies>
          <!-- web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.2.0</version>
        </dependency>
        
        
        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        
        
        <!-- 热部署 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        
        <!-- redis cache related.....start -->  
        <dependency>  
            <groupId>org.springframework.data</groupId>  
            <artifactId>spring-data-redis</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>redis.clients</groupId>  
            <artifactId>jedis</artifactId>  
        </dependency>
    </dependencies>

  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>
View Code

    (3)添加redis工具类

    

package com.sun.beans;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.data.redis.core.BoundSetOperations;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.ListOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Service;

@Service
public class RedisCacheUtil<T>
{

    
    @Autowired @Qualifier("jedisTemplate")
    public RedisTemplate redisTemplate;
    

    
    /**
     * 缓存基本的对象,Integer、String、实体类等
     * @param key    缓存的键值
     * @param value    缓存的值
     * @return        缓存的对象
     */
    public <T> ValueOperations<String,T> setCacheObject(String key,T value)
    {
        
        ValueOperations<String,T> operation = redisTemplate.opsForValue(); 
        operation.set(key,value);
        return operation;
    }
    
    /**
     * 获得缓存的基本对象。
     * @param key        缓存键值
     * @param operation
     * @return            缓存键值对应的数据
     */
    public <T> T getCacheObject(String key/*,ValueOperations<String,T> operation*/)
    {
        ValueOperations<String,T> operation = redisTemplate.opsForValue(); 
        return operation.get(key);
    }
    
    /**
     * 缓存List数据
     * @param key        缓存的键值
     * @param dataList    待缓存的List数据
     * @return            缓存的对象
     */
    public <T> ListOperations<String, T> setCacheList(String key,List<T> dataList)
    {
        ListOperations listOperation = redisTemplate.opsForList();
        if(null != dataList)
        {
            int size = dataList.size();
            for(int i = 0; i < size ; i ++)
            {
                
                listOperation.rightPush(key,dataList.get(i));
            }
        }
        
        return listOperation;
    }
    
    /**
     * 获得缓存的list对象
     * @param key    缓存的键值
     * @return        缓存键值对应的数据
     */
    @SuppressWarnings({ "unchecked", "hiding" })
    public <T> List<T> getCacheList(String key)
    {
        List<T> dataList = new ArrayList<T>();
        ListOperations<String,T> listOperation = redisTemplate.opsForList();
        Long size = listOperation.size(key);
        
        for(int i = 0 ; i < size ; i ++)
        {
            dataList.add((T) listOperation.leftPop(key));
        }
        
        return dataList;
    }
    
    /**
     * 缓存Set
     * @param key        缓存键值
     * @param dataSet    缓存的数据
     * @return            缓存数据的对象
     */
    @SuppressWarnings({ "unchecked", "hiding" })
    public <T> BoundSetOperations<String,T> setCacheSet(String key,Set<T> dataSet)
    {
        BoundSetOperations<String,T> setOperation = redisTemplate.boundSetOps(key);    
        /*T[] t = (T[]) dataSet.toArray();
             setOperation.add(t);*/
        
        
        Iterator<T> it = dataSet.iterator();
        while(it.hasNext())
        {
            setOperation.add(it.next());
        }
        
        return setOperation;
    }
    
    /**
     * 获得缓存的set
     * @param key
     * @param operation
     * @return
     */
    public Set<T> getCacheSet(String key/*,BoundSetOperations<String,T> operation*/)
    {
        Set<T> dataSet = new HashSet<T>();
        BoundSetOperations<String,T> operation = redisTemplate.boundSetOps(key);    
        
        Long size = operation.size();
        for(int i = 0 ; i < size ; i++)
        {
            dataSet.add(operation.pop());
        }
        return dataSet;
    }
    
    /**
     * 缓存Map
     * @param key
     * @param dataMap
     * @return
     */
    public <T> HashOperations<String,String,T> setCacheMap(String key,Map<String,T> dataMap)
    {
        
        HashOperations hashOperations = redisTemplate.opsForHash();
        if(null != dataMap)
        {
            
            for (Map.Entry<String, T> entry : dataMap.entrySet()) {  
                  
                /*System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());  */
                hashOperations.put(key,entry.getKey(),entry.getValue());
            } 
            
        }
        
        return hashOperations;
    }
    
    /**
     * 获得缓存的Map
     * @param key
     * @param hashOperation
     * @return
     */
    public <T> Map<String,T> getCacheMap(String key/*,HashOperations<String,String,T> hashOperation*/)
    {
        Map<String, T> map = redisTemplate.opsForHash().entries(key);
        /*Map<String, T> map = hashOperation.entries(key);*/
        return map;
    }
    
    
    
    
    
    
    
    /**
     * 缓存Map
     * @param key
     * @param dataMap
     * @return
     */
    public <T> HashOperations<String,Integer,T> setCacheIntegerMap(String key,Map<Integer,T> dataMap)
    {
        HashOperations hashOperations = redisTemplate.opsForHash();
        if(null != dataMap)
        {
            
            for (Map.Entry<Integer, T> entry : dataMap.entrySet()) {  
                  
                /*System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());  */
                hashOperations.put(key,entry.getKey(),entry.getValue());
            } 
            
        }
        
        return hashOperations;
    }
    
    /**
     * 获得缓存的Map
     * @param key
     * @param hashOperation
     * @return
     */
    public <T> Map<Integer,T> getCacheIntegerMap(String key/*,HashOperations<String,String,T> hashOperation*/)
    {
        Map<Integer, T> map = redisTemplate.opsForHash().entries(key);
        /*Map<String, T> map = hashOperation.entries(key);*/
        return map;
    }
}
View Code

    (4)添加redis监听,项目启动时自动缓存数据

package com.sun.beans;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.Resource;

import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Service;

import com.sun.dao.UserMapper;
import com.sun.model.User;

/*
 * 监听器,用于项目启动的时候初始化信息
 */
@Service
public class StartAddCacheListener implements ApplicationListener<ContextRefreshedEvent>
{
    @Resource
    private RedisCacheUtil<Object> redisCache;
    

    @Resource
    private UserMapper userMapper;
    
    @Override
    public void onApplicationEvent(ContextRefreshedEvent  event) 
    { 
        //spring 启动的时候缓存user等信息
        if(event.getApplicationContext().getParent() == null)
        {
            System.out.println("


_________

缓存数据 

 ________



");
            List<User> userList = userMapper.selectAll();
            
            Map<Integer,User> userMap = new HashMap<Integer,User>();
            
            int cityListSize = userList.size();
            
            for(int i = 0 ; i < cityListSize ; i ++ )
            {
                userMap.put(userList.get(i).getId(), userList.get(i));
            }
            
            
            redisCache.setCacheIntegerMap("userMap", userMap);
        }
    }
    
}
View Code

    

    (5)修改TestController添加如下代码:

    

@Autowired
    private RedisCacheUtil<User> redisCache;

    @RequestMapping("/testGetCache")
    public String testGetCache()
    {

        System.out.println("------------user");
        Map<Integer,User> userMap = redisCache.getCacheIntegerMap("userMap");
        for(int key : userMap.keySet())
        {
            System.out.println("key = " + key + ",value=" + userMap.get(key));
        }
        return userMap.toString();
    }

注意:这里要序列化User实体类,也就是public class User  implements Serializable{

3、总结

  (1)redis是用客户端jedis操作的。所以jedis包我都是手动添加,工程根节点building path-》

  

这样添加的。如果你有更好的方式,请留言。版本号是2.9.0。

而且做这个redis的时候我发现版本号的问题十分讨厌,在网上下了redis的windows安装版本,但是安装了却没有jar包,

所以又在网上下了redis的3.2.100版本,但是却在工程里不知道版本号怎么写,后来使用的例子代码多了,发现maven管理的jar包中最高有1.8的,

就一直这么写了,有大神可以分析下为什么吗?

(2)redis的Windows版是自启动的,这样我改了redis-server.conf密码后,在项目中仍然设置了密码,提示auth错误。

注释掉项目中的密码设置就可以了。

(3)在applicationContext.xml中设置redis的配置文件,查资料说2种方式都可以,但是发现一种是报错的,只有

<context:property-placeholder location="classpath*:redis.properties" ignore-unresolvable="true" /> 这样可行,不知道为什么?有大神解答么?

(4)添加了几个配置文件applicationContext.xml和redis.properties和spring-redis.xml。

需要注意在启动类中的扫描代码:

@ImportResource(locations={"classpath:applicationContext.xml"})

最后给一下源码https://github.com/sunfengjiajia/spring-boot-test

欢迎大家加我qq:309620263探讨技术问题。
原文地址:https://www.cnblogs.com/PPBoy/p/7126681.html