Question

我正在基于Java的Hbase客户端编写一些非常基本的东西，用于在已启用的现有表上执行扫描操作。该计划基于： https://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/package-summary.html

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.Get;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.Put;
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.util.Bytes;
import org.apache.hadoop.hbase.protobuf.generated.*;


public class FirstHBaseClient {
  public static void main(String[] args) throws IOException {

    Configuration config = HBaseConfiguration.create();

    Connection connection = ConnectionFactory.createConnection(config);
    try {


      Table table = connection.getTable(TableName.valueOf("test"));
      try {

        Scan s = new Scan();
        ResultScanner scanner = table.getScanner(s);
        try {

           for (Result rr = scanner.next(); rr != null; rr = scanner.next()) {
             // print out the row we found and the columns we were looking for
             System.out.println("Found row: " + rr);
           }

         } finally {

           scanner.close();
         }

       } finally {
         if (table != null) table.close();
       }
     } finally {
       connection.close();
     }
  }
}

编译和执行很好......会话正在建立。但是我没有从扫描操作中得到任何结果，为什么？ Eclipse控制台输出：

15/09/17 19:37:18 INFO zookeeper.ZooKeeper: Client environment:user.dir=/root/workspace_hbase/HBaseIntro
15/09/17 19:37:18 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=90000 watcher=hconnection-0xea4a92b0x0, quorum=localhost:2181, baseZNode=/hbase
15/09/17 19:37:18 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
15/09/17 19:37:18 INFO zookeeper.ClientCnxn: Socket connection established to localhost/127.0.0.1:2181, initiating session
15/09/17 19:37:18 INFO zookeeper.ClientCnxn: Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x14fde0f7576000e, negotiated timeout = 40000

我做错了什么？我在Ubuntu Linux上使用Hbase - 1.1.2版本并运行JDK1.8.x。

Answer 1

Pheonix是完全不同的数据检索方法...... 我希望在那个测试时，测试数据可用!!! 以下代码应该有效。

for (Result result = scanner.next(); (result != null); result = scanner.next()) {
    for(KeyValue keyValue : result.list()) {
        System.out.println("Qualifier : " + keyValue.getKeyString() + " : Value : " + Bytes.toString(keyValue.getValue()));
    }
}

来自Java的HBase扫描api

1 个答案: