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Hbase 的Java API 操作

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Hbase 的Java API 操作 

 

package com.wzt.dao;

//package hbaseExec2;

/*
* 创建一个students表,并进行相关操作
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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.KeyValue;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
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;

public class HBaseJavaAPI {
  // 声明静态配置
  private static Configuration conf = null;

  static {
      conf = HBaseConfiguration.create();
      conf.set("hbase.zookeeper.quorum", "cloud5:2181,cloud6:2181,cloud7:2181");
  }

  //判断表是否存在
  private static boolean isExist(String tableName) throws IOException {
      HBaseAdmin hAdmin = new HBaseAdmin(conf);
      return hAdmin.tableExists(tableName);
  }

  // 创建数据库表
  public static void createTable(String tableName, String[] columnFamilys)
          throws Exception {
      // 新建一个数据库管理员
      HBaseAdmin hAdmin = new HBaseAdmin(conf);
      if (hAdmin.tableExists(tableName)) {
          System.out.println("表 "+tableName+" 已存在！");
          System.exit(0);
      } else {
          // 新建一个students表的描述
          HTableDescriptor tableDesc = new HTableDescriptor(tableName);
          // 在描述里添加列族
          for (String columnFamily : columnFamilys) {
              tableDesc.addFamily(new HColumnDescriptor(columnFamily));
          }
          // 根据配置好的描述建表
          hAdmin.createTable(tableDesc);
          System.out.println("创建表 "+tableName+" 成功!");
      }
  }

  // 删除数据库表
  public static void deleteTable(String tableName) throws Exception {
      // 新建一个数据库管理员
      HBaseAdmin hAdmin = new HBaseAdmin(conf);
      if (hAdmin.tableExists(tableName)) {
          // 关闭一个表
          hAdmin.disableTable(tableName);
          hAdmin.deleteTable(tableName);
          System.out.println("删除表 "+tableName+" 成功！");
      } else {
          System.out.println("删除的表 "+tableName+" 不存在！");
          System.exit(0);
      }
  }

  // 添加一条数据
  public static void addRow(String tableName, String row,
          String columnFamily, String column, String value) throws Exception {
      HTable table = new HTable(conf, tableName);
      Put put = new Put(Bytes.toBytes(row));// 指定行
      // 参数分别:列族、列、值
      put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column),
              Bytes.toBytes(value));
      table.put(put);
  }

  // 删除一条(行)数据
  public static void delRow(String tableName, String row) throws Exception {
      HTable table = new HTable(conf, tableName);
      Delete del = new Delete(Bytes.toBytes(row));
      table.delete(del);
  }

  // 删除多条数据
  public static void delMultiRows(String tableName, String[] rows)
          throws Exception {
      HTable table = new HTable(conf, tableName);
      List<Delete> delList = new ArrayList<Delete>();
      for (String row : rows) {
          Delete del = new Delete(Bytes.toBytes(row));
          delList.add(del);
      }
      table.delete(delList);
  }

  // 获取一条数据
  public static void getRow(String tableName, String row) throws Exception {
      HTable table = new HTable(conf, tableName);
      Get get = new Get(Bytes.toBytes(row));
      Result result = table.get(get);
      // 输出结果,raw方法返回所有keyvalue数组
      for (KeyValue rowKV : result.raw()) {
          System.out.print("行名:" + new String(rowKV.getRow()) + " ");
          System.out.print("时间戳:" + rowKV.getTimestamp() + " ");
          System.out.print("列族名:" + new String(rowKV.getFamily()) + " ");
          System.out.print("列名:" + new String(rowKV.getQualifier()) + " ");
          System.out.println("值:" + new String(rowKV.getValue()));
      }
  }

  // 获取所有数据
  public static void getAllRows(String tableName) throws Exception {
      HTable table = new HTable(conf, tableName);
      Scan scan = new Scan();
      ResultScanner results = table.getScanner(scan);
      // 输出结果
      for (Result result : results) {
          for (KeyValue rowKV : result.raw()) {
              System.out.print("行名:" + new String(rowKV.getRow()) + " ");
              System.out.print("时间戳:" + rowKV.getTimestamp() + " ");
              System.out.print("列族名:" + new String(rowKV.getFamily()) + " ");
              System.out
                      .print("列名:" + new String(rowKV.getQualifier()) + " ");
              System.out.println("值:" + new String(rowKV.getValue()));
          }
      }
  }

  // 主函数
  public static void main(String[] args) {
      try {
          String tableName = "student";
          // 第一步：创建数据库表：“student”
          String[] columnFamilys = { "info", "course" };
          HBaseJavaAPI.createTable(tableName, columnFamilys);
          // 第二步：向数据表的添加数据
          // 添加第一行数据
          if (isExist(tableName)) {
              HBaseJavaAPI.addRow(tableName, "zpc", "info", "age", "20");
              HBaseJavaAPI.addRow(tableName, "zpc", "info", "sex", "boy");
              HBaseJavaAPI.addRow(tableName, "zpc", "course", "china", "97");
              HBaseJavaAPI.addRow(tableName, "zpc", "course", "math", "128");
              HBaseJavaAPI.addRow(tableName, "zpc", "course", "english", "85");
              // 添加第二行数据
              HBaseJavaAPI.addRow(tableName, "henjun", "info", "age", "19");
              HBaseJavaAPI.addRow(tableName, "henjun", "info", "sex", "boy");
              HBaseJavaAPI.addRow(tableName, "henjun", "course", "china","90");
              HBaseJavaAPI.addRow(tableName, "henjun", "course", "math","120");
              HBaseJavaAPI.addRow(tableName, "henjun", "course", "english","90");
              // 添加第三行数据
              HBaseJavaAPI.addRow(tableName, "niaopeng", "info", "age", "18");
              HBaseJavaAPI.addRow(tableName, "niaopeng", "info", "sex","girl");
              HBaseJavaAPI.addRow(tableName, "niaopeng", "course", "china","100");
              HBaseJavaAPI.addRow(tableName, "niaopeng", "course", "math","100");
              HBaseJavaAPI.addRow(tableName, "niaopeng", "course", "english","99");
              // 第三步：获取一条数据
              System.out.println("**************获取一条(zpc)数据*************");
              HBaseJavaAPI.getRow(tableName, "zpc");
              // 第四步：获取所有数据
              System.out.println("**************获取所有数据***************");
              HBaseJavaAPI.getAllRows(tableName);

              // 第五步：删除一条数据
              System.out.println("************删除一条(zpc)数据************");
              HBaseJavaAPI.delRow(tableName, "zpc");
              HBaseJavaAPI.getAllRows(tableName);
              // 第六步：删除多条数据
              System.out.println("**************删除多条数据***************");
              String rows[] = new String[] { "qingqing","xiaoxue" };
              HBaseJavaAPI.delMultiRows(tableName, rows);
              HBaseJavaAPI.getAllRows(tableName);
              // 第七步：删除数据库
              System.out.println("***************删除数据库表**************");
              HBaseJavaAPI.deleteTable(tableName);
              System.out.println("表"+tableName+"存在吗？"+isExist(tableName));
          } else {
              System.out.println(tableName + "此数据库表不存在！");
          }

      } catch (Exception e) {
          e.printStackTrace();
      }
  }

}

 

from  http://www.2cto.com/database/201503/381955.html 

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