wiki:NCHCCloudCourse100929_4_HBEX

Version 10 (modified by waue, 10 years ago) (diff)

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HBase 進階課程
程式範例練習

回課程大綱 << 第一關 > 下一關

注意

  • 請將以下給個 hbase 重要的檔複製到 hadoop lib 目錄下,並且重新啟動 hbase 與 hadoop
    $ cd /opt/hbase
    $ cp hbase-*.jar lib/zookeeper-3.2.2.jar contrib/transactional/hbase-0.20.6-transactional.jar /opt/hadoop/lib/
    $ /opt/hbase/bin/stop-hbase.sh
    $ /opt/hadoop/bin/stop-all.sh
    $ /opt/hadoop/bin/start-all.sh
    $ /opt/hbase/bin/start-hbase.sh
    
  • 若編譯以下範例的環境為console 端,請設定完整的classpath,詳細方法請看教材投影片
  • 若開發是透過 eclipse ,請將 hbase-core.jar , zookeeper*.jar , hbase-*-transactional.jar 匯入到 project library 中,詳細方法請看教材投影片
  • 注意: 若此程式執行於 eclipse ,則方便起見,請將程式的 eclipse only 的後兩行的註解取消,如:
        // eclipse only
        String[] args = {"ex1Table","Detail"};
        argv = args;
    

範例一:新增Table

bin/hadoop jar TCRCExample.jar CreateTable ex1Table Detail

CreateTable.java

package org.nchc.hbase;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.util.GenericOptionsParser;

public class CreateTable {
  public static void createHBaseTable(String tablename, String family)
      throws IOException {
    // HTableDescriptor 用來描述table的屬性
    HTableDescriptor htd = new HTableDescriptor(tablename);

    // HTableDescriptor 透過 add() 方法來加入Column family
    htd.addFamily(new HColumnDescriptor(family));

    // HBaseConfiguration 能接收 hbase-site.xml 的設定值
    HBaseConfiguration config = new HBaseConfiguration();

    // 檔案的操作則使用 HBaseAdmin
    HBaseAdmin admin = new HBaseAdmin(config);

    // 檢查
    if (admin.tableExists(tablename)) {
      System.out.println("Table: " + tablename + "Existed.");
    } else {

      // 建立
      admin.createTable(htd);

      // 
      System.out.println( tablename + " created.");
    }
  }

  static public void main(String argv[]) throws IOException {
    // eclipse only
//    String[] args = {"ex1Table","Detail"};
//    argv = args;

    String[] otherArgs = new GenericOptionsParser(new Configuration(), argv)
        .getRemainingArgs();
    if (otherArgs.length < 2) {
      System.out.println("CreateTable <newTableName> <Family>");
      return;
    }
    
    String tablename = otherArgs[0];
    String family = otherArgs[1];

    System.out.println("1. create table :" + tablename);

    createHBaseTable(tablename, family);
  }
}


  • 執行結果
1. create table :ex1Table
ex1Table created.