小编mvg*_*mvg的帖子

我正在尝试制作一个非常简单的Kafka Producer,我目前正在关注生产者示例,除了我的生产者没有分区器类.

将所需文件导出到jar后,我将它们传输到我的Linux映像并尝试运行它.

我得到这个例外:

Exception in thread "main" java.lang.reflect.InvocationTargetException
    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 org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)
Caused by: java.lang.NoClassDefFoundError: org/apache/kafka/common/utils/Utils
    at kafka.client.ClientUtils$$anonfun$parseBrokerList$1.apply(ClientUtils.scala:103)
    at kafka.client.ClientUtils$$anonfun$parseBrokerList$1.apply(ClientUtils.scala:102)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:194)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:194)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:60)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:44)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:194)
    at scala.collection.mutable.ArrayBuffer.map(ArrayBuffer.scala:44)
    at kafka.client.ClientUtils$.parseBrokerList(ClientUtils.scala:102)
    at kafka.producer.BrokerPartitionInfo.<init>(BrokerPartitionInfo.scala:32)
    at kafka.producer.async.DefaultEventHandler.<init>(DefaultEventHandler.scala:41)
    at kafka.producer.Producer.<init>(Producer.scala:60)
    at kafka.javaapi.producer.Producer.<init>(Producer.scala:26)
    at producers.HelloWorldProducer.main(HelloWorldProducer.java:20)
    ... 5 more
Caused by: java.lang.ClassNotFoundException: org.apache.kafka.common.utils.Utils
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 19 more

在看了kafka jar之后,我发现utils …

我正在学习不可变的对象.我正在尝试这段代码

  public final class ImmutableObject {

    private final String name;

    private final NormalObject obj =  new NormalObject();

    public String getName() {
        return name;
    }


    public ImmutableObject(String name) {
        this.name = name;
        obj.setName(name);
    }


    public NormalObject getObj() {

        NormalObject tempObj = obj;
        return tempObj;
    }
}

public class NormalObject {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

我想限制调用类更改NormalObject的name变量的值

但是以下代码更改了值

 ImmutableObject obj = new ImmutableObject("Siddle");

 System.out.println(obj.getObj().getName()); //prints Siddle
 obj.getObj().setName("Kelly"); …

我是Hibernate的新手.我正在使用JSF,Spring和Hibernate创建一个Web应用程序.我正在尝试使用hibernate实现从用户过滤器生成的此查询

select * from ( Select DATE_FORMAT(a.call_offered_time,'%d %b %Y %k:%i:%s') As 'call_date', a.caller_id as 'Caller', DATE_FORMAT(a.call_offered_time,'%d %b %Y %k:%i:%s') as  'Call Connected', DATE_FORMAT(a.call_disconnect_time,'%d %b %Y %k:%i:%s') as 'Call Disconnected',a.channel_no as 'Channel', a.call_status as 'Call Status', (Case When  a.call_routed_to_agent=Null or  a.call_routed_to_agent='' then 'IVRS' Else call_routed_to_agent  End ) as 'Call Routed To', b.ddi,TIMESTAMPDIFF(SECOND,a.call_offered_time,a.call_disconnect_time) as 'Duration'from CallDetail a,ddi_details b Where a.call_reference_no =b.call_reference_no and a.call_offered_time Between '2006-01-01 00:00:00' And '2010-11-20 23:59:00') as t order by STR_TO_DATE(t.call_date,'%d %b %Y %k:%i:%s')

为此,我尝试了以下代码

Session session = null; …

我正在浏览Hadoop-权威指南,我遇到了这些问题:

规范化给MapReduce带来了问题,因为它使得读取记录成为非本地操作,而MapReduce的一个主要假设是可以执行(高速)流读取和写入.

有人可以解释这些线条在外行语言中的实际含义吗？

我知道什么是规范化.它是如何使读取记录成为非本地操作的？参考hadoop的非本地操作是什么意思？