參考

Lua 腳本
Programming in Lua

api

• 使用 RedisScript<T>
• 使用 RedisTemplate.execute(RedisScript<T> script, List<K> keys, Object... args)

幾點(diǎn)需要關(guān)注的地方

redisScript.resultType

事實(shí)上， DefaultScriptExecutor 拿到 connection.eval 的返回結(jié)果后， 只是判斷 redisScript.resultType 是否為空，為空則直接返回為空，
如果不為空， 則根據(jù) 返回結(jié)果是 byte[] 還是 list 調(diào)用反序列化函數(shù)進(jìn)行反序列化。

    protected <T> T eval(RedisConnection connection, RedisScript<T> script, ReturnType returnType, int numKeys,
                byte[][] keysAndArgs, RedisSerializer<T> resultSerializer) {
    
            Object result;
            try {
                result = connection.evalSha(script.getSha1(), returnType, numKeys, keysAndArgs);
            } catch (Exception e) {
    
                if (!exceptionContainsNoScriptError(e)) {
                    throw e instanceof RuntimeException ? (RuntimeException) e : new RedisSystemException(e.getMessage(), e);
                }
    
                result = connection.eval(scriptBytes(script), returnType, numKeys, keysAndArgs);
            }
    
            if (script.getResultType() == null) {
                return null;
            }
    
            return deserializeResult(resultSerializer, result);
    }
        
    ....
    
    
    @SuppressWarnings({ "rawtypes", "unchecked" })
    protected <T> T deserializeResult(RedisSerializer<T> resultSerializer, Object result) {
        if (result instanceof byte[]) {
            if (resultSerializer == null) {
                return (T) result;
            }
            return resultSerializer.deserialize((byte[]) result);
        }
        if (result instanceof List) {
            List results = new ArrayList();
            for (Object obj : (List) result) {
                results.add(deserializeResult(resultSerializer, obj));
            }
            return (T) results;
        }
        return (T) result;
    }
    

而序列化工具類則是調(diào)用 RedisTemplate

public <T> T execute(final RedisScript<T> script, final List<K> keys, final Object... args) {
        // use the Template's value serializer for args and result
        return execute(script, template.getValueSerializer(), (RedisSerializer<T>) template.getValueSerializer(), keys,
                args);
}

返回值

redis 的返回值里, 只有 byte[] 字節(jié), 或者 list<byte[]> 的我值數(shù)據(jù), 所以不要寫以下的代碼
foo 下的數(shù)據(jù)不會(huì)返回.

local result = { foo = "name", "breaker", "time" }
return result

關(guān)于參數(shù)

    @SuppressWarnings("unchecked")
    public <T> T execute(final RedisScript<T> script, final List<K> keys, final Object... args) {
        // use the Template's value serializer for args and result
        return execute(script, template.getValueSerializer(), (RedisSerializer<T>) template.getValueSerializer(), keys,
                args);
    }
    
    ... 
    
    @SuppressWarnings({ "unchecked", "rawtypes" })
    protected byte[][] keysAndArgs(RedisSerializer argsSerializer, List<K> keys, Object[] args) {
        final int keySize = keys != null ? keys.size() : 0;
        byte[][] keysAndArgs = new byte[args.length + keySize][];
        int i = 0;
        if (keys != null) {
            for (K key : keys) {
                if (keySerializer() == null && key instanceof byte[]) {
                    keysAndArgs[i++] = (byte[]) key;
                } else {
                    keysAndArgs[i++] = keySerializer().serialize(key);
                }
            }
        }
        for (Object arg : args) {
            if (argsSerializer == null && arg instanceof byte[]) {
                keysAndArgs[i++] = (byte[]) arg;
            } else {
                keysAndArgs[i++] = argsSerializer.serialize(arg);
            }
        }
        return keysAndArgs;
    }

顯然, key 與 args 都是有使用 redisTemplate 的 值 序列化進(jìn)行處理.

關(guān)于多個(gè)序列化工具的問(wèn)題,

有時(shí)候,我們想對(duì)key 與值采用不同的序列化工具, 如 key , 使用 string 序列化, value 使用 json 序列化, 從代碼上看, 需要重寫
redisTemplate

另外, 如果想在 lua 腳本中使用 json, 可以使用全局變量 cjson

local value = { true, { foo = 'mindasset', joo = 'java' } }
local json_text = cjson.encode(value)

return json_text