SpringBoot + Thymeleaf + redis实现页面缓存

先奉上redis操做工具类html

package com.hz1202.miaosha.service;

import com.alibaba.fastjson.JSON;
import com.hz1202.miaosha.redis.KeyPrefix;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;

/**
 * @Author: mol
 * @Description:
 * @Date: create in 13:19 2018/5/3
 */
@Service
public class RedisService {

    @Autowired
    JedisPool jedisPool;

    /**
     * redis get方法(该工具中为了保证全部key都惟一  因此给每个key都加了前缀)
     * @param prefix 前缀
     * @param key key值
     * @param clazz 获取后要转换成的对象类型
     * @return 转换后的对象
     */
    public <T> T get(KeyPrefix prefix,String key, Class<T> clazz){
        Jedis jedis = null;
        try {
            //获取jedis
            jedis = jedisPool.getResource();
            //获取真正的key
            String realKey = prefix.getPrefix()+key;
            String str = jedis.get(realKey);
            //将获取到的String转换成clazz对象
            T t = StringToBean(str,clazz);
            return t;
        }finally {
            //完成后回收资源
            returnToPool(jedis);
        }
    }

    /**
     * redis set方法(该工具中为了保证全部key都惟一  因此给每个key都加了前缀)
     * @param prefix 前缀
     * @param key key值
     * @param value 要保存的数据
     */
    public <T> Boolean set(KeyPrefix prefix,String key,T value){
        Jedis jedis = null;
        try {
            //获取jedis
            jedis = jedisPool.getResource();
            //将对象转换为字符串
            String str = beanToString(value);
            if(str == null || str.length() <= 0){
                return false;
            }
            //生成真正的key
            String realKey = prefix.getPrefix()+key;
            //获取key有效时间
            int seconds = prefix.expireSeconds();
            //若是有效时间小于等于0,说名该key值永久有效,不然在保存数据时须要加入有效时间
            if(seconds <= 0){
                jedis.set(realKey,str);
            }else{
                jedis.setex(realKey,seconds,str);
            }
            return true;
        }finally {
            returnToPool(jedis);
        }
    }

    /**
     * 判断key是否存在
     * @param prefix 前缀
     * @param key key值
     * @return
     */
    public Boolean exists(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix()+key;
            jedis.exists(realKey);
            return true;
        }finally {
            returnToPool(jedis);
        }
    }


    /**
     * 给当前的key对应的value + 1
     * @param prefix 前缀
     * @param key key值
     * @return
     */
    public Boolean incr(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix()+key;
            jedis.incr(realKey);
            return true;
        }finally {
            returnToPool(jedis);
        }
    }

    /**
     * 给当前key对应的value - 1
     * @param prefix 前缀
     * @param key key
     * @return
     */
    public Boolean decr(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            //生成真正的key
            String realKey = prefix.getPrefix()+key;
            jedis.decr(realKey);
            return true;
        }finally {
            returnToPool(jedis);
        }
    }

    /**
     * 将对象转换为字符串
     * @param value
     * @param <T>
     * @return
     */
    private <T> String beanToString(T value) {
        if(value == null){
            return null;
        }
        Class<?> clazz = value.getClass();
        if(clazz == int.class || clazz == Integer.class){
            return  value+"";
        }else if(clazz == String.class){
            return (String) value;
        }else if(clazz == Long.class || clazz == long.class){
            return  value+"";
        }else{
            return JSON.toJSONString(value);
        }
    }

    /**
     * 将String 转换为对象
     * @param str
     * @param clazz
     * @param <T>
     * @return
     */
    @SuppressWarnings("unchecked")
    private <T> T StringToBean(String str,Class<T> clazz) {
        if(str == null || str.length() <= 0 || clazz == null){
            return null;
        }
        if(clazz == int.class || clazz == Integer.class){
            return  (T)Integer.valueOf(str);
        }else if(clazz == String.class){
            return (T)str;
        }else if(clazz == Long.class || clazz == long.class){
            return  (T)Long.valueOf(str);
        }else{
            return JSON.toJavaObject(JSON.parseObject(str),clazz);
        }
    }

    /**
     * 回收redis资源
     * @param jedis
     */
    private void returnToPool(Jedis jedis) {
        if(jedis!=null){
            jedis.close();
        }
    }
}

前缀和有效时间前端

package com.hz1202.miaosha.redis;

/**
 * @Author: mol
 * @Description:
 * @Date: create in 14:46 2018/5/3
 */
public abstract class BasePrefix implements KeyPrefix{

    //有效时间
    private int expireSeconds;

    //前缀
    private String prefix;

    public BasePrefix(String prefix) {
       this.expireSeconds = 0;
       this.prefix = prefix;
    }

    public BasePrefix(int expireSeconds, String prefix) {
        this.expireSeconds = expireSeconds;
        this.prefix = prefix;
    }

    @Override
    public int expireSeconds() {//默认0表明永不过时
        return expireSeconds;
    }

    @Override
    public String getPrefix() {
        String simpleName = getClass().getSimpleName();
        return simpleName+":"+prefix;
    }
}
package com.hz1202.miaosha.redis;

/**
 * @Author: mol
 * @Description:
 * @Date: create in 14:44 2018/5/3
 */
public interface KeyPrefix {

    int expireSeconds();

    String getPrefix();
}

各个模块的前缀和有效时间均可以经过继承 BasePrefix  来控制java

例如商品模块redis

package com.hz1202.miaosha.redis;

public class GoodsKey extends BasePrefix {

    private GoodsKey(String prefix,int expireSeconds) {
        super(expireSeconds,prefix);
    }
    
    //前缀为“gl”有效时间为“60”秒
    public static GoodsKey getGoodsList =new GoodsKey("gl",60);
    //前缀为“gd”有效时间为“60”秒
    public static GoodsKey getGoodsDetail =new GoodsKey("gd",60);

}

正常状况下咱们可能经过如下代码进入商品列表页面spring

@RequestMapping(value = "/to_list")
    public String toListHtml(Model model){
        List<GoodsVo> goodsVos = goodsService.listGoodsVo();
        model.addAttribute("goodsList",goodsVos);
        return "goods_list";
    }

在作页面缓存时,咱们直接将一个HTML代码返回给前端页面json

@RequestMapping(value = "/to_list",produces="text/html")
    @ResponseBody
    public String toListHtml(Model model, MiaoShaUser user, HttpServletRequest request,
                             HttpServletResponse response){
        //取缓存
        String str = redisService.get(GoodsKey.getGoodsList, "", String.class);
        if(!StringUtils.isEmpty(str)){
            return str;
        }
        //缓存中没有,咱们先获取商品信息
        List<GoodsVo> goodsVos = goodsService.listGoodsVo();
        model.addAttribute("goodsList",goodsVos);
        model.addAttribute("user",user);
        //而后进行手动渲染
        SpringWebContext swc = new SpringWebContext(request,response,request.getServletContext(),
                request.getLocale(),model.asMap(),application);
        //goods_list 指的是前端页面模版(即你要将数据返回到哪一个页面)
        str = thymeleafViewResolver.getTemplateEngine().process("goods_list", swc);
        //存入redis
        if(!StringUtils.isEmpty(str)){
            redisService.set(GoodsKey.getGoodsList,"",str);
        }
        return str;
    }

以上咱们看处处理页面缓存,只须要在原有的基础上作如下处理:缓存

一、在RequestMapping中加上 produces = "text/html",表示该方法将产生HTML代码数据app

二、先从redis中获取数据ide

三、若是redis中没有数据则经过业务逻辑获取相关的数据后进行手动渲染,生成HTML代码,而后存入redis,最后将生成的代码返回给模板工具