大数据之路Week10_day07 (JavaAPI 操作Redis 与Hbase建立索引，通过查询redis中的索引查询Hbase数据）

在这里是简单模拟将索引存到redis中，再通过先查询索引再将Hbase中的数据查询出来。

需要考虑的问题：

　　1、建立redis的连接，建立Hbase的连接

　　2、如何创建索引，即创建索引的key和value的设计

　　3、如何通过将查到的索引，去查询到对应Hbase的数据

代码的难度并不大，主要是这个思路。

package com.wyh.redis;


import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import redis.clients.jedis.Jedis;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Set;


/**
 * 通过存在redis的索引查询Hbase的数据
 */
public class HbaseOnRediseIndex {
    private HConnection conn;
    private HBaseAdmin admin;
    private Jedis jedis;


    /**
     * 初始化建立连接
     * 连接Hbase，连接到redis
     *
     */
    @Before
    public void Cli(){
        try {
            //建立与Hbase的连接
            Configuration conf = new Configuration();
            conf.set("hbase.zookeeper.quorum","master:2181,node1:2181,node2:2181");
            conn = HConnectionManager.createConnection(conf);
            admin = new HBaseAdmin(conf);

            //建立与redis的连接
            jedis = new Jedis("master", 6379);
            System.out.println("与Hbase建立连接成功。。"+conn);
            System.out.println("与redis建立连接成功。。"+jedis);

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


    /**
     * 创建表将学生信息导入到Hbase中
     *
     */
    @Test
    public void createTable(){
        try {
            HTableDescriptor student2 = new HTableDescriptor("student2");
            HColumnDescriptor info = new HColumnDescriptor("info");

            student2.addFamily(info);

            String name = Bytes.toString(student2.getName());

            admin.createTable(student2);

            System.out.println(name+"表 创建成功。。。");
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    /**
     * 往创建的Hbase表中put数据
     */
    @Test
    public void putData(){
        try {
            ArrayList<Put> puts = new ArrayList<>();

            HTableInterface student2 = conn.getTable("student2");
            BufferedReader br = new BufferedReader(new FileReader("D:\shujia\shujia006\hadoop\src\data\students.txt"));
            String line;
            while ((line=br.readLine())!=null){
                String[] split = line.split(",");
                String id = split[0];
                String name = split[1];
                String age = split[2];
                String gender = split[3];
                String clazz = split[4];


                Put put = new Put(id.getBytes());
                put.add("info".getBytes(),"name".getBytes(),name.getBytes());
                put.add("info".getBytes(),"age".getBytes(),age.getBytes());
                put.add("info".getBytes(),"gender".getBytes(),gender.getBytes());
                put.add("info".getBytes(),"clazz".getBytes(),clazz.getBytes());

                puts.add(put);
            }


            student2.put(puts);
            System.out.println("数据插入完毕。。。");

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


    /**
     * 读取数据，将学号插入到redis当作索引
     * set集合的方式
     *
     */
    @Test
    public void setData(){
        try {
            String tableName = "student_gender";
            BufferedReader br = new BufferedReader(new FileReader("D:\shujia\shujia006\hadoop\src\data\students.txt"));
            String line;
            while ((line=br.readLine())!=null){
                String[] split = line.split(",");
                String id = split[0];

                String gender = split[3];
                String key = tableName +":" + gender;
                jedis.sadd(key,id);
            }

            System.out.println("redis索引构建完毕。。。");

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 通过redis的索引查询Hbase的数据
     *      先查询索引表，再查询Hbase
     *
     */
    @Test
    public void indexData(){

        String gender = "男";

        Set<String> set = jedis.smembers("student_gender:" + gender);

        System.out.println("所有性别为 "+ gender+" 的学生如下：");
        for (String id : set) {

            try {
                HTableInterface student2 = conn.getTable("student2");
                Get get = new Get(id.getBytes());

                Result result = student2.get(get);
                if(result!=null){
                    String id1 = Bytes.toString(result.getRow());
                    String name = Bytes.toString(result.getValue("info".getBytes(), "name".getBytes()));
                    String age = Bytes.toString(result.getValue("info".getBytes(), "age".getBytes()));
                    String gander1 = Bytes.toString(result.getValue("info".getBytes(), "gender".getBytes()));
                    String clazz = Bytes.toString(result.getValue("info".getBytes(), "clazz".getBytes()));

                    System.out.println(id1+"	"+name+"	"+age+"	"+gander1+"	"+clazz);
                }

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


        }


    }




    /**
     * 关闭连接
     */
    @After
    public void close(){
        if(admin!=null){
            try {
                admin.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        if(conn!=null){
            try {
                conn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        if(jedis!=null){
            jedis.close();
        }


    }



}