Hadoop生态组件之Hive环境搭建--第十讲(hive实战-java连接hive)

1.确认虚拟机防火墙已经关闭

2.启动hive

    2.1 shell模式

            切换到bin下    ./hive启动

    2.2 hive JDBC服务

            ./hive --service hiveserver2 &

   2.3测试jdbc连接是否可用

            切换到bin下    ./beeline

            然后输入  !connect jdbc:hive2://ip地址:10000 root root  后面两个是你创建的用户名和密码

如果能连接上就表示 jdbc没有问题了

            注： !connect jdbc:hive2://localhost:10000/hive root root  这里不要使用localhost，应该使用配置的ip

3.java操作

package com.lanqiao;
import java.sql.Connection;  
import java.sql.DriverManager;  
import java.sql.ResultSet;  
import java.sql.SQLException;  
import java.sql.Statement;  
  
import org.apache.log4j.Logger;  
  
/** 
 * Hive的JavaApi 
 *   
 * @author haowl
 *  
 */  
public class HiveJdbcCli {  
  
    private static String driverName = "org.apache.hive.jdbc.HiveDriver";  
    private static String url = "jdbc:hive2://192.168.0.107:10000/hive";  
    private static String user = "root";  
    private static String password = "root";  
    private static String sql = "";  
    private static ResultSet res;  
    private static final Logger log = Logger.getLogger(HiveJdbcCli.class);  
  
    public static void main(String[] args) {  
        Connection conn = null;  
        Statement stmt = null;  
        try {  
            conn = getConn();  
            System.out.println(conn);
            
            stmt = conn.createStatement();  
  
            // 第一步:存在就先删除  
            String tableName = dropTable(stmt);  
  
            // 第二步:不存在就创建  
            createTable(stmt, tableName);  
  
            // 第三步:查看创建的表  
            showTables(stmt, tableName);  
  
            // 执行describe table操作  
            describeTables(stmt, tableName);  
  
            // 执行load data into table操作  
            loadData(stmt, tableName);  
  
            // 执行 select * query 操作  
            selectData(stmt, tableName);  
  
            // 执行 regular hive query 统计操作  
            countData(stmt, tableName);  
  
        } catch (ClassNotFoundException e) {  
            e.printStackTrace();  
            log.error(driverName + " not found!", e);  
            System.exit(1);  
        } catch (SQLException e) {  
            e.printStackTrace();  
            log.error("Connection error!", e);  
            System.exit(1);  
        } finally {  
            try {  
                if (conn != null) {  
                    conn.close();  
                    conn = null;  
                }  
            } catch (SQLException e) {  
                e.printStackTrace();  
            } 
        }  
    }  
  
    private static void countData(Statement stmt, String tableName)  
            throws SQLException {  
        sql = "select count(1) from " + tableName;  
        System.out.println("Running:" + sql);  
        res = stmt.executeQuery(sql);  
        System.out.println("执行“regular hive query”运行结果:");  
        while (res.next()) {  
            System.out.println("count ------>" + res.getString(1));  
        }  
    }  
  
    private static void selectData(Statement stmt, String tableName)  
            throws SQLException {  
        sql = "select * from " + tableName;  
        System.out.println("Running:" + sql);  
        res = stmt.executeQuery(sql);  
        System.out.println("执行 select * query 运行结果:");  
        while (res.next()) {  
            System.out.println(res.getInt(1) + "\t" + res.getString(2));  
        }  
    }  
  
    private static void loadData(Statement stmt, String tableName)  
            throws SQLException {  
        String filepath = "/root/training/data/data.txt";  
        sql = "load data local inpath '" + filepath + "' into table "  
                + tableName;  
        System.out.println("Running:" + sql);  
        stmt.execute(sql);  
    }  
  
    private static void describeTables(Statement stmt, String tableName)  
            throws SQLException {  
        sql = "describe " + tableName;  
        System.out.println("Running:" + sql);  
        res = stmt.executeQuery(sql);  
        System.out.println("执行 describe table 运行结果:");  
        while (res.next()) {  
            System.out.println(res.getString(1) + "\t" + res.getString(2));  
        }  
    }  
  
    private static void showTables(Statement stmt, String tableName)  
            throws SQLException {  
        sql = "show tables '" + tableName + "'";  
        System.out.println("Running:" + sql);  
        res = stmt.executeQuery(sql);  
        System.out.println("执行 show tables 运行结果:");  
        if (res.next()) {  
            System.out.println(res.getString(1));  
        }  
    }  
    
    private static void createTable(Statement stmt, String tableName)  
            throws SQLException {  
        sql = "create table "  
                + tableName  
                + " (key int, value string)  row format delimited fields terminated by '\t'";  
        stmt.execute(sql);  
    }  
  
    private static String dropTable(Statement stmt) throws SQLException {  
        // 创建的表名  
        String tableName = "testHive";  
        sql = "drop table " + tableName;  
        stmt.execute(sql);  
        return tableName;  
    }  
  
    private static Connection getConn() throws ClassNotFoundException,  
            SQLException {  
        Class.forName(driverName);  
        Connection conn = DriverManager.getConnection(url, user, password);  
        return conn;  
    }  
  
}