小编use*_*253的帖子

如果我创建一个新的Date()对象.它将打印的默认时区是什么.

我的机器在GMT运行.我正在创建一个新的Date()对象.如果我打印为什么它显示Thu Jul 05 08:21:05 PKT 2012.如何将时区作为PKT？

什么时候我们应该使用这种方法.在JedisConnectionException,JedisDataException或任何JedisException上.据我所知,Jedis没有好的API文档.

try {
    Jedis jedis = JedisFactory.getInstance();
    Pipeline pipe = jedis.pipelined();
    Response<Set<Tuple>> idWithScore = pipe.zrangeWithScores(cachekey, from, to);
    **// some statement which may cause some other exception**
    Response<String> val = pipe.get(somekey);
    pipe.exec();
    pipe.sync();
}catch (JedisConnectionException e) {
    JedisFactory.returnBrokenResource(jedis);
}catch(Exception e){
    **// What API I should use here?, how to find whether to use returnBrokenResource(jedis) or returnResource(jedis)**
}finally{
    JedisFactory.returnResource(jedis);
}

QueueingConsumer consumer = new QueueingConsumer(channel);
System.out.println(consumer.getConsumerTag());
channel.basicConsume("queue1", consumer);
channel.basicConsume("queue3", consumer);

是否可以动态地单独停止从队列"queue3"中消费消息？

我试图在spark任务中使用lambda表达式,并抛出"java.lang.IllegalArgumentException:无效的lambda反序列化"异常.当代码如"transform(pRDD-> pRDD.map(t-> t._2))"时抛出此异常.代码片段如下.

JavaPairDStream<String,Integer> aggregate = pairRDD.reduceByKey((x,y)->x+y);
JavaDStream<Integer> con = aggregate.transform(
(Function<JavaPairRDD<String,Integer>, JavaRDD<Integer>>)pRDD-> pRDD.map( 
(Function<Tuple2<String,Integer>,Integer>)t->t._2));


JavaPairDStream<String,Integer> aggregate = pairRDD.reduceByKey((x,y)->x+y);
JavaDStream<Integer> con = aggregate.transform(
(Function<JavaPairRDD<String,Integer>, JavaRDD<Integer>> & Serializable)pRDD-> pRDD.map( 
(Function<Tuple2<String,Integer>,Integer> & Serializable)t->t._2));

以上两个选项没有奏效.好像我把对象"f"作为参数传递而不是lambda表达式"t-> t_.2".有用.

Function f = new Function<Tuple2<String,Integer>,Integer>(){
@Override
public Integer call(Tuple2<String,Integer> paramT1) throws Exception {
return paramT1._2;
}
}; 

我可以知道将该函数表示为lambda表达式的正确格式是什么.

    public static void main(String[] args) {

            Function f = new Function<Tuple2<String,Integer>,Integer>(){

                @Override
                public Integer call(Tuple2<String,Integer> paramT1) throws Exception {
                    return paramT1._2;
                }

            };

            JavaStreamingContext ssc = JavaStreamingFactory.getInstance();

            JavaReceiverInputDStream<String> lines …

在Jedis中使用Response Object,抛出ClassCastException.当我使用管道时,我无法从Redis获得任何价值.请帮忙.我正在使用Jedis 2.1.0

public class JedisPipeline {    
    public static void main(String args[]){
        final JedisPool pool = new JedisPool(new JedisPoolConfig(), "127.0.0.1", 6379);
        Jedis jedis = pool.getResource();
        Pipeline pipeline = jedis.pipelined();
        pipeline.multi();
        HashMap<String,String> map = new HashMap<String,String>();
        map.put("50", "50");
        pipeline.hmset("Id",map);
        Response <Long> incr = pipeline.hincrBy("Id", "100", 100);
        Response<Map<String,String>> map1 = pipeline.hgetAll("Id");
        pipeline.exec();
        List<Object> results = pipeline.syncAndReturnAll();
        System.out.println(results);
        System.out.println( incr.get());
        System.out.println( map1.get());
        pool.returnResource(jedis);
        pool.destroy();
    }
}

Exception in thread "main" java.lang.ClassCastException: [B cannot be cast to java.lang.Long
    at redis.clients.jedis.BuilderFactory$4.build(BuilderFactory.java:45)
    at redis.clients.jedis.BuilderFactory$4.build(BuilderFactory.java:48)
    at redis.clients.jedis.Response.get(Response.java:27) …