原文链接:https://www.cnblogs.com/commissar-Xia/p/7759484.html
最近使用Redis优化项目功能,其中有一部分为模糊查询,找了很多帖子,也没有找到很好的解决方案和思路,最终皇天不负有心人啊,终于让我找到了!!!
感谢该帖作者:WalkerAlone 原文链接:http://blog.csdn.net/qq_28893679/article/details/53005057
可以通过Redis中keys命令进行获取key值,具体命令格式:keys pattern
文中提到redis中允许模糊查询的有3个通配符,分别是:*,?,[]
其中:
*:通配任意多个字符
?:通配单个字符
[]:通配括号内的某一个字符
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在实际项目中有可能会使用spring集成redis的RedisTemplate进行操作,这样在注入模板时可能会出现模糊查询不好用的情况,是因为
keys方法是存在于StringRedisTemplate子类中(父类-RedisTemplate)的
在spring配置时,一定要注意!!!
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实际操作中具体的思路:
1. 将要查询的条件当做key进行ZSet存储
2. 在获取时,调用StringRedisTemplate.keys(pattern),例:
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5
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public
Set keys(String pattern){
return
stringRedisTemplate.keys(
"*"
+ pattern +
"*"
);
// return stringRedisTemplate.keys("?" + pattern);
// return stringRedisTemplate.keys("[" + pattern + "]");
}
|
ps:模糊查找适用于 String数据结构,对redis支持的其他结构(List、set等),没有 验证是否支持。
实践代码:
/**
* redis缓存操作类
*/
@Service
public class RedisCacheService implements InitializingBean {
private ValueOperations<String, String> valueOperations;
@Autowired
private StringRedisTemplate redisTemplate;
@SuppressWarnings("unchecked")
@Override
public void afterPropertiesSet() throws Exception {
RedisSerializer<String> redisSerializer = new StringRedisSerializer();
valueOperations = redisTemplate.opsForValue();
}
/**
* 从缓存中获取资源信息
* @param key
* @return
*/
public List<ResourceCacheBO> getCacheResource(String key) {
Set<String> keys = redisTemplate.keys(key);
if (CollectionUtils.isEmpty(keys)) {
return new ArrayList<>();
}
List<ResourceCacheBO> resourceCacheBOList = new ArrayList<>();
for (String accurateKey : keys) {
String cacheValue = valueOperations.get(accurateKey);
List<ResourceCacheBO> sub = JSONArray.parseArray(cacheValue, ResourceCacheBO.class);
resourceCacheBOList.addAll(sub);
}
return resourceCacheBOList;
}
遇到问题:存在key:“A_091_JPFX”,但是用 模糊key:“A_*_JPFX”匹配时,却匹配不到;有资料说是编码问题,按下面方式解决:
原文链接:
redisTemplate.keys(pattern)模糊查询找不到keys:https://blog.csdn.net/cutterwolf/article/details/77990112
在使用redisTemplate.keys查找keys时,发现明明相应的key是存在的,模糊查询就是查找不出来;原因有二:
1.确定你的查询字符串是否正确
2.就是的你key值有可能是乱码了就是遇到\xca\xed加上你key之类的乱码!例如:这里写图片描述
你需要重新定义key
@Bean
public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {
RedisTemplate<String, String> redisTemplate = new RedisTemplate<String, String>();
redisTemplate.setConnectionFactory(factory);
//key序列化方式;(不然会出现乱码;),但是如果方法上有Long等非String类型的话,会报类型转换错误;
//所以在没有自己定义key生成策略的时候,以下这个代码建议不要这么写,可以不配置或者自己实现ObjectRedisSerializer
//或者JdkSerializationRedisSerializer序列化方式;
RedisSerializer<String> redisSerializer = new StringRedisSerializer();//Long类型不可以会出现异常信息;
redisTemplate.setKeySerializer(redisSerializer);
redisTemplate.setHashKeySerializer(redisSerializer);
return redisTemplate;
}
完整代码:
package cn.xxt.word.analysis.service;
import cn.xxt.ssm.commons.exception.BizException;
import cn.xxt.ssm.commons.json.JacksonJsonUtil;
import cn.xxt.word.analysis.pojo.bo.QuestCacheBO;
import cn.xxt.word.analysis.pojo.bo.ResourceCacheBO;
import com.alibaba.fastjson.JSONArray;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
/**
* redis缓存操作类
*/
@Service
public class RedisCacheService implements InitializingBean {
private ValueOperations<String, String> valueOperations;
@Autowired
private StringRedisTemplate redisTemplate;
@SuppressWarnings("unchecked")
@Override
public void afterPropertiesSet() throws Exception {
RedisSerializer<String> redisSerializer = new StringRedisSerializer();//Long类型不可以会出现异常信息;
redisTemplate.setKeySerializer(redisSerializer);
redisTemplate.setHashKeySerializer(redisSerializer);
valueOperations = redisTemplate.opsForValue();
}
/**
* 缓存资源
* @param key
* @param resourceCacheBOList
*/
public void cacheResource(String key, List<ResourceCacheBO> resourceCacheBOList) {
// 参数校验
if (CollectionUtils.isEmpty(resourceCacheBOList)) {
throw new BizException(1, "参数有误");
}
// 缓存
String resourceCacheValue = JacksonJsonUtil.objectToString(resourceCacheBOList);
valueOperations.set(key, resourceCacheValue);
}
/**
* 从缓存中获取资源信息
* @param key
* @return
*/
// TODO 待测试
public List<ResourceCacheBO> getCacheResource(String key) {
Set<String> keys = redisTemplate.keys(key);
if (CollectionUtils.isEmpty(keys)) {
return new ArrayList<>();
}
List<ResourceCacheBO> resourceCacheBOList = new ArrayList<>();
for (String accurateKey : keys) {
String cacheValue = valueOperations.get(accurateKey);
List<ResourceCacheBO> sub = JSONArray.parseArray(cacheValue, ResourceCacheBO.class);
resourceCacheBOList.addAll(sub);
}
return resourceCacheBOList;
}
/**
* 缓存 关键字的编码
* @param key
* @return
*/
public void cacheKeyWordCode(String key, String code) {
// 参数校验
if (StringUtils.isEmpty(key) || StringUtils.isEmpty(code)) {
throw new BizException(1, "参数有误");
}
// 缓存
valueOperations.set(key, code);
}
/**
* 获取 关键字的编码
* @param key
* @return
*/
public String getKeyWordCode(String key) {
String keyWordCode = valueOperations.get(key);
if (StringUtils.isEmpty(keyWordCode)) {
return null;
} else {
return keyWordCode;
}
}
/**
* 批量获取 关键字的编码
* @param keys
* @return
*/
public List<String> batchGetKeyWordCode(List<String> keys) {
List<String> codes = valueOperations.multiGet(keys);
if (CollectionUtils.isEmpty(codes)) {
return new ArrayList<>();
} else {
codes.removeAll(Collections.singleton(null));
return codes;
}
}
}