springboot redis自定义KeyGenerator----单机版-蒲公英云

springboot redis自定义KeyGenerator----单机版

这个自定义在单机情况正常，集群情况下不能很好的对同一接口生成一样的hash key，需要考虑所缓存的方法有固定类参数，比如这个方法参数为User.class,或者Student.class。

public class MCacheKeyGenerator implements KeyGenerator {
    public static final Logger LOGGER = LoggerFactory.getLogger(MCacheKeyGenerator.class);
    // custom cache key
    public static final int NO_PARAM_KEY = 0;
    public static final int NULL_PARAM_KEY = 53;
    @Override
    public Object generate(Object target, Method method, Object... params) {
        StringBuilder key = new StringBuilder();
        Cacheable cacheable = method.getAnnotation(Cacheable.class);
        if (null!=cacheable && StringUtils.isNotBlank(cacheable.value().toString())){
            key.append(cacheable.value());
        }
        LOGGER.info("Cache Key cacheable'value: {}", cacheable.value()[0]);
        key.append(cacheable.value()[0] + "::");
        if (params.length == 0) {
            key.append(NO_PARAM_KEY);
            LOGGER.info("params's length is 0 Cache Key: {}", key);
        } else {
            if (params.length == 1) {
                Object param = params[0];
                if (param == null) {
                    key.append(NULL_PARAM_KEY);
                    LOGGER.info("param is null Cache Key: {}", key);
                } else if (!param.getClass().isArray()) {
                    key.append(param);
                    LOGGER.info("param is not array Cache Key: {}", key);
                }
            } else {
                //注意这个调用的deepHashCode，可能会有在不同机器产生不同hash的情况
                key.append(Arrays.deepHashCode(params));
                LOGGER.info("deepHashCode(params) Cache Key: {}", key);
            }
        }
        return key.toString();
    }
}