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我写了一个hbase java客户端如下。

package hbase;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;

public class Sample {


    public static void main(String[] args) throws IOException{
        // Instantiating Configuration class
           System.out.println("Trying to connect...");

           Configuration conf = HBaseConfiguration.create();
           System.out.println("HBase is running!");

           Connection conn = ConnectionFactory.createConnection(conf);
           Table  table = conn.getTable(TableName.valueOf("demo"));
           Scan scan1 = new Scan();

           ResultScanner scanner1 = table.getScanner(scan1);

           for(Result res: scanner1){
               System.out.print(res);
           }

           System.out.println("Table created Successfully...");

    }
}

以下是输出

Trying to connect...
HBase is running!
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
2017-03-22 18:24:32.271 java[29447:3527085] Unable to load realm mapping info from SCDynamicStore
Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: java.lang.NullPointerException
    at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:208)
    at org.apache.hadoop.hbase.client.ClientScanner.call(ClientScanner.java:320)
    at org.apache.hadoop.hbase.client.ClientScanner.nextScanner(ClientScanner.java:295)
    at org.apache.hadoop.hbase.client.ClientScanner.initializeScannerInConstruction(ClientScanner.java:160)
    at org.apache.hadoop.hbase.client.ClientScanner.<init>(ClientScanner.java:155)
    at org.apache.hadoop.hbase.client.HTable.getScanner(HTable.java:821)
    at hbase.Sample.main(Sample.java:29)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException
    at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:208)
    at org.apache.hadoop.hbase.client.ClientSmallReversedScanner.loadCache(ClientSmallReversedScanner.java:211)
    at org.apache.hadoop.hbase.client.ClientSmallReversedScanner.next(ClientSmallReversedScanner.java:185)
    at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegionInMeta(ConnectionManager.java:1249)
    at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1155)
    at org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.getRegionLocations(RpcRetryingCallerWithReadReplicas.java:300)
    at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:151)
    at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:59)
    at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
    ... 6 more
Caused by: java.lang.NullPointerException
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.getMetaReplicaNodes(ZooKeeperWatcher.java:395)
    at org.apache.hadoop.hbase.zookeeper.MetaTableLocator.blockUntilAvailable(MetaTableLocator.java:553)
    at org.apache.hadoop.hbase.client.ZooKeeperRegistry.getMetaRegionLocation(ZooKeeperRegistry.java:61)
    at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateMeta(ConnectionManager.java:1185)
    at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1152)
    at org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.getRegionLocations(RpcRetryingCallerWithReadReplicas.java:300)
    at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:151)
    at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:59)
    at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
    ... 14 more

我已经使用 hbase shell 在 hbase 中创建了一个表。我在 OS X EI Captian 上运行 HDP 2.5 和我的 eclipse 代码。
我在本地路径中复制了 hbase-site.xml。

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1 回答 1

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根据您的代码，我可以理解您正在创建 HbaseConfiguration 而不在您的类中添加任何配置信息。所以我假设你会在类路径中添加 hbase-site.xml。如果没有，您必须添加它或在您的类中设置 zookeeper znode 和 quorum 详细信息，如下所示。

       Configuration conf = HBaseConfiguration.create();
       conf.set("zookeeper.znode.parent", <hbase znode>) 
       conf.set("hbase.zookeeper.quorum", <quorum ip>);
       conf.set("hbase.zookeeper.property.clientPort", <port>);

       Connection conn = ConnectionFactory.createConnection(conf);
于 2017-03-23T16:36:56.237 回答