小编div*_*gon的帖子

假设我插入了5个字符串ArrayList.插入和检索的顺序ArrayList是否相同？

有没有办法以JSON格式转换Hive查询结果？

我正在尝试阅读有关Kafka主题的消息,但我无法阅读它.一段时间后该进程被杀死,无需读取任何消息.

这是我得到的重新平衡错误:

[2014-03-21 10:10:53,215] ERROR Error processing message, stopping consumer:  (kafka.consumer.ConsoleConsumer$)
kafka.common.ConsumerRebalanceFailedException: topic-1395414642817-47bb4df2 can't rebalance after 4 retries
    at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.syncedRebalance(ZookeeperConsumerConnector.scala:428)
    at kafka.consumer.ZookeeperConsumerConnector.kafka$consumer$ZookeeperConsumerConnector$$reinitializeConsumer(ZookeeperConsumerConnector.scala:718)
    at kafka.consumer.ZookeeperConsumerConnector$WildcardStreamsHandler.<init>(ZookeeperConsumerConnector.scala:752)
    at kafka.consumer.ZookeeperConsumerConnector.createMessageStreamsByFilter(ZookeeperConsumerConnector.scala:142)
    at kafka.consumer.ConsoleConsumer$.main(ConsoleConsumer.scala:196)
    at kafka.consumer.ConsoleConsumer.main(ConsoleConsumer.scala)
Consumed 0 messages

我试图跑ConsumerOffsetChecker,这是我得到的错误.我不知道如何解决这个问题.任何人,任何想法？

./kafka-run-class.sh kafka.tools.ConsumerOffsetChecker --zkconnect localhost:9092 --topic mytopic --group  topic_group
Group           Topic                          Pid Offset          logSize         Lag             Owner
Exception in thread "main" org.I0Itec.zkclient.exception.ZkNoNodeException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /consumers/
        at org.I0Itec.zkclient.exception.ZkException.create(ZkException.java:47)
        at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:685)
        at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:766)
        at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:761)
        at kafka.utils.ZkUtils$.readData(ZkUtils.scala:459)
        at kafka.tools.ConsumerOffsetChecker$.kafka$tools$ConsumerOffsetChecker$$processPartition(ConsumerOffsetChecker.scala:59)
        at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply$mcVI$sp(ConsumerOffsetChecker.scala:89)
        at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:89)
        at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:89) …

我使用以下代码块来生成MD5哈希:

public static String encode(String data) throws Exception {

    /* Check the validity of data */
    if (data == null || data.isEmpty()) {
        throw new IllegalArgumentException("Null value provided for "
                + "MD5 Encoding");
    }

    /* Get the instances for a given digest scheme MD5 or SHA */
    MessageDigest m = MessageDigest.getInstance("MD5");

    /* Generate the digest. Pass in the text as bytes, length to the
     * bytes(offset) to be hashed; for full string pass 0 to text.length()
     */
    m.update(data.getBytes(), 0, data.length()); …

我有一个非常基本的Spring Boot应用程序,它期望来自命令行的参数,并且没有它不起作用.这是代码.

@SpringBootApplication
public class Application implements CommandLineRunner {

    private static final Logger log = LoggerFactory.getLogger(Application.class);

    @Autowired
    private Reader reader;

    @Autowired
    private Writer writer;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Override
    public void run(String... args) throws Exception {

        Assert.notEmpty(args);

        List<> cities = reader.get("Berlin");
         writer.write(cities);
    }
}

这是我的JUnit测试类.

@RunWith(SpringRunner.class)
@SpringBootTest
public class CityApplicationTests {

    @Test
    public void contextLoads() {
    }
}

现在,Assert.notEmpty()要求传递一个论点.但是,现在,我正在编写JUnit测试.但是,我得到了以下异常加注Assert.

2016-08-25 16:59:38.714 ERROR 9734 --- [           main] o.s.boot.SpringApplication               : Application startup failed …

为什么相同的JSON目标代码使用ul元素生成输出,但不生成table标记.

我有我的Mustache模板,如:

<div id="template-ul">
    <h3>{{name}}</h3>
    <ul>
        {{#students}}
        <li>{{name}} - {{age}}</li>
        {{/students}}
    </ul>
</div>

<div id="template-table">
    <table>
        <thead>
            <th>Name</th>
            <th>Age</th>
        </thead>
        <tbody>
        {{#students}}
            <tr>
                <td>{{name}}</td>
                <td>{{age}}</td>
            </tr>
        {{/students}}
        </tbody>
    </table>
</div>

这是javascript代码:

var testing = {
    "name" : "student-collection",
    "students" : [
        {
            "name" : "John",
            "age" : 23
        },
        {
            "name" : "Mary",
            "age" : 21
        }
    ]
};

var divUl = document.getElementById("template-ul");
var divTable = document.getElementById("template-table");

divUl.innerHTML = Mustache.render(divUl.innerHTML, testing);
divTable.innerHTML = Mustache.render(divTable.innerHTML, testing);

这是jsFiddle上的代码 …

我正在尝试启动ActiveMQ 5.11,我看到WARNING如下:

 WARN | Transport Connection to: tcp://127.0.0.1:40890 failed: java.io.EOFException

我activemq.xml的如下:

<transportConnectors>
    <transportConnector name="openwire" uri="tcp://0.0.0.0:${JMS_PORT}" />
    <transportConnector name="stomp" uri="stomp://0.0.0.0:${JMS_STOMP_PORT}"/>
    <transportConnector name="ssl" uri="ssl://0.0.0.0:${JMS_SSL_PORT}"/>
</transportConnectors>

<sslContext>
    <sslContext
        keyStore="file:${JMS_KEY_STORE}"
        keyStorePassword="${JMS_KEY_STORE_PASSWORD}"
        trustStore="file:${JMS_TRUST_STORE}"
        trustStorePassword="${JMS_TRUST_STORE_PASSWORD}"
    />
</sslContext>

<networkConnectors>
    <networkConnector 
        name="host1 and host2" 
        uri="static://(${JMS_X_SITE_CSV_URL})?wireFormat=ssl&amp;wireFormat.maxInactivityDuration=30000"
        dynamicOnly="true"
        suppressDuplicateQueueSubscriptions = "true"
        networkTTL="1"
    />
</networkConnectors>

这是整个控制台日志.

Java Runtime: Oracle Corporation 1.7.0_05 /usr/java/jdk1.7.0_05/jre
  Heap sizes: current=1004928k  free=994439k  max=1004928k
    JVM args: -Xmx1G -Dorg.apache.activemq.UseDedicatedTaskRunner=true -Djava.util.logging.config.file=logging.properties -Djava.security.auth.login.config=/home/dragon/activemq/conf/login.config -Dcom.sun.management.jmxremote -Djava.io.tmpdir=/home/dragon/activemq/tmp -Dactivemq.classpath=/home/dragon/activemq/conf; -Dactivemq.home=/home/dragon/activemq -Dactivemq.base=/home/dragon/activemq -Dactivemq.conf=/home/dragon/activemq/conf -Dactivemq.data=/home/dragon/activemq/data
Extensions classpath:
  [/home/dragon/activemq/lib,/home/dragon/activemq/lib/camel,/home/dragon/activemq/lib/optional,/home/dragon/activemq/lib/web,/home/dragon/activemq/lib/extra]
ACTIVEMQ_HOME: /home/dragon/activemq
ACTIVEMQ_BASE: /home/dragon/activemq …

我不知道如何,但我的STS有重复的工具栏项目,我不知道如何删除它们.这是我的重复工具栏的样子.

我想摆脱这些.我试图隐藏工具栏,但这没有帮助.有没有人知道如何摆脱重复的？

考虑一个hadoop集群,其默认块大小为64MB hdfs-site.xml.但是,后来团队决定将此更改为128MB.以下是我对上述场景的疑问？

1. 此更改是否需要重新启动群集,否则它将自动占用,所有新文件的默认块大小为128MB？
2. 块大小为64M的现有文件会发生什么？配置中的更改是否会自动应用于现有文件？如果它将自动完成,那么何时完成 - 一旦完成更改或群集启动？如果没有自动完成,那么如何手动执行此块更改？

我想在map中计算类似的值,其中key是Hive表列中的值,对应的值是count.

例如,对于下表:

+-------+-------+
| Col 1 | Col 2 |
+-------+-------+
| Key1  | Val1  |
| Key1  | Val2  |
| Key2  | Val1  |
+-------+-------+

所以hive查询应该返回类似的东西

Key1=2
Key2=1