redis SCAN 代替 keys *

话不多说直接干代码:

keys * 这个命令别在生产环境乱用。特别是数据庞大的情况下。因为Keys会引发Redis锁,并且增加Redis的CPU占用。很多公司的运维都是禁止了这个命令的, 后续的操作 会导致连接耗尽报错。

基于 scan 进行操作

 /**
     * 通过scan 获取redis key 避免阻塞
     * @param redisTemplate redisTemplate
     * @param redisPattern 需要匹配的key
     * @param size 每次指定扫描的key的数量
     */
    public Set<Object> redisScanFormatValue(RedisTemplate<String,Object> redisTemplate,String redisPattern,long size){
    
    

        return redisTemplate.execute((RedisCallback<Set<Object>>) redisConnection->{
    
    
            Set<Object> keySet =  new HashSet<>();
            try (Cursor<byte[]> scan = redisConnection.scan(new ScanOptions.ScanOptionsBuilder().match(redisPattern).count(size).build())){
    
    
                while (scan.hasNext()){
    
    
                    byte[] bytes = redisConnection.get(scan.next());
                    Object deserialize = redisTemplate.getValueSerializer().deserialize(bytes);
                    keySet.add(deserialize);
                }
            }catch ( Exception e){
    
    
                e.printStackTrace();
            }
            return keySet;
        });
    }

    /**
     * 通过scan 获取redis key 避免阻塞
     * @param redisTemplate redisTemplate
     * @param redisPattern 需要匹配的key
     * @param size 每次指定扫描的key的数量
     */
    public Set<String> redisScanFormatKey(RedisTemplate<String,Object> redisTemplate,String redisPattern,long size) {
    
    
        return redisTemplate.execute((RedisCallback<Set<String>>)connect->{
    
    
           Set<String> keySet = new HashSet<>();
            try (Cursor<byte[]> cursor = connect.scan(ScanOptions.scanOptions().match(redisPattern).count(size).build())){
    
    
                while (cursor.hasNext()){
    
    
                    byte[] next = cursor.next();
                    Object deserialize = redisTemplate.getKeySerializer().deserialize(next);
                    keySet.add(String.valueOf(deserialize));
                }
            }catch (Exception e){
    
    
                e.printStackTrace();
            }
           return keySet;
        });
    }

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转载自blog.csdn.net/qq_16183731/article/details/120008031