簡介

hive是基于Hadoop的一個數據倉庫工具，可以將結構化的數據文件映射為一張數據庫表，并提供簡單的sql查詢功能，可以將sql語句轉換為MapReduce任務進行運行。

安裝

API

hive ddl

 如果文件數據是純文本，可以使用 STORED AS TEXTFILE。如果數據需要壓縮，使用 STORED AS SEQUENCE 

使用

//啟動
cd /
//進入命令行環(huán)境
/opt/hive/bin/hive
//語句
show tables;
create table test(key string);
insert into test values("123");
select * from test;

java操作

//依賴
<dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-jdbc</artifactId>
        <version>2.1.0</version>
</dependency>
<dependency>  
    <groupId>org.apache.hadoop</groupId>  
    <artifactId>hadoop-common</artifactId>  
    <version>2.6.0</version>  
</dependency>
//啟動服務
 hive --service hiveserver2

java示例程序

package com.test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class HiveJdbcClient {
    private static String driverName = "org.apache.hive.jdbc.HiveDriver"; 
    public static void main(String[] args) throws SQLException {  
       try {  
          Class.forName(driverName);  
        } catch (ClassNotFoundException e) {  
          // TODO Auto-generated catch block  
          e.printStackTrace();  
          System.exit(1);  
        }  
    
        //hive的默認端口是 10000，如果要修改就修改 hive-site.xml 文件的hive.server2.thrift.port 屬性值          
        Connection con = DriverManager.getConnection("jdbc:hive2://192.168.1.150:10000/default", "hadoop", "123456");  
          
        Statement stmt = con.createStatement();

        //測試的表名 testhivedrivertable  
        String tableName = "testhivedrivertable";  
          
        //如果已經存在就刪除  
        stmt.execute("drop table if exists " + tableName);  
          
        //創(chuàng)建這張表  
        stmt.execute("create table " + tableName + " (key int, value string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\054'");  
        //看下創(chuàng)建是否成功  
        String sql = "show tables '" + tableName + "'";  
        System.out.println("Running: " + sql);  
        ResultSet res = stmt.executeQuery(sql);  
        if (res.next()) {  
          System.out.println(res.getString(1));  
        }  
          
        //看下表結構  
        sql = "describe " + tableName;  
        System.out.println("Running: " + sql);  
        res = stmt.executeQuery(sql);  
        while (res.next()) {  
          System.out.println(res.getString(1) + "\t" + res.getString(2));  
        }    
    }
}

示例程序運行結果

Paste_Image.png

報錯

1. hadoop is not allowed to impersonate anonymous
   API參考

#hadoop:core-site.xml
#這里不能設置為root
<property><name>hadoop.proxyuser.hadoop.hosts</name><value>*</value></property>
<property><name>hadoop.proxyuser.hadoop.groups</name><value>*</value></property>
#重啟hadoop
#java程序
#設置用戶名hadoop,不使用空
Connection con = DriverManager.getConnection("jdbc:hive2://192.168.1.100:10000/default", "hadoop", "123456");

參考文章

Hive:用Java代碼通過JDBC連接Hiveserver
hadoop is not allowed to impersonate anonymous