java - Jedis 管道异常

Question

当我像下面的代码一样使用 jedis 时:

public class JedisTest extends Sync {
    private static final String _SET_KEY_1 = "test1";
    private static final String _SET_KEY_2 = "test2";

    public void process() throws SQLException {
        Set<String> appSet = getAllUserableAppkey();
        final ShardedJedis jedis = RedisHelper.getJedis();
        final ShardedJedisPipeline pipeline = jedis.pipelined();

        for (String key : appSet) {
            Set<String> result = jedis.smembers(_SET_KEY_1);
            Set<String> result2 = jedis.smembers(_SET_KEY_2);
            String rangName = String.format("%s::%s", "test", key);
            for (int i = 0; i < 10; i++) {
                pipeline.sadd(rangName, String.valueOf(i));
            }
        }
        pipeline.sync();
    }

    public Set<String> getAllUserableAppkey() {

    }

    public static void main(String[] args) throws Exception {
        DbHelper.init();
        RedisHelper.init();
        JedisTest jedisTest = new JedisTest();
        try {
            jedisTest.process();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

它像这样抛出异常:

Exception in thread "main" java.lang.ClassCastException: java.lang.Long cannot be cast to java.util.List
    at redis.clients.jedis.Connection.getBinaryMultiBulkReply(Connection.java:224)
    at redis.clients.jedis.Connection.getMultiBulkReply(Connection.java:217)
    at redis.clients.jedis.Jedis.smembers(Jedis.java:1055)
    at redis.clients.jedis.ShardedJedis.smembers(ShardedJedis.java:339)
    at com.snda.sync.impl.test.JedisTest.process(JedisTest.java:29)
    at com.snda.sync.impl.test.JedisTest.main(JedisTest.java:58)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

我可以修改代码来更正:

public void process() throws SQLException {
    Set<String> appSet = getAllUserableAppkey();
    final ShardedJedis jedis = RedisHelper.getJedis();
    for (String key : appSet) {
        final ShardedJedisPipeline pipeline = jedis.pipelined();
        Set<String> result = jedis.smembers(_SET_KEY_1);
        Set<String> result2 = jedis.smembers(_SET_KEY_2);
        //log.warn("result1 :{},result2:{}",result,result2);
        String rangName = String.format("%s::%s", "test", key);
        for (int i = 0; i < 10; i++) {
            pipeline.sadd(rangName, String.valueOf(i));
        }
        pipeline.sync();
    }
}

但我不知道为什么会抛出异常，pipline.sadd() 是否与 jedis.smembers 冲突？谢谢你回答我!

绝地武士最新:2.7.2

Answer 1

你不应该在流水线时直接使用 Jedis 实例。

管道使用 Jedis 实例的流(不初始化新流)，并且由于正常操作立即读取响应而管道稍后读取整个响应，混淆两种用法会使 Jedis 陷入困境。

P -- 流水线式/N -- 普通

请求 --> P(1) P(2) N(3) N(4) P(5)

Redis 响应 --> P(1) P(2) N(3) N(4) P(5)

匹配的请求-响应 --> N(1: 应该是 3) N(2: 应该是 4) P(3: 应该是 1) P(4: 应该是 2) P(5)

您可以看到响应很容易有缺陷。