Hive的JDBC使用&并把JDBC放置后台运行

使用JDBC访问HIVE:

首先启动hive的JDBC服务.

进入hive的bin目录:

这样启动是启动到前台.如果 要想启动到后台需要用到Linux的相关命令.

我们先把其放到前台看下效果,之后再把它放到后台.

查看这个启动的服务是否已经能够监听到了.

这之后就可以编写JDBC代码了.

以word count为例子.

示例代码如下:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class HiveJdbc {
    private static String driverName = "org.apache.hive.jdbc.HiveDriver";
    private static String url = "jdbc:hive2://192.168.1.99:10002/default";
    private static String user = "root";
    private static String password = "";
    private static String sql = "";
    private static ResultSet res;
    
    public static void main(String[] args) throws Exception {
        Class.forName(driverName);
        Connection conn = DriverManager.getConnection(url, user, password);
        sql = "select word,count(word) as count from (select explode(split(line,' ')) word from t_wordcount) w group by word";
        PreparedStatement prepStmt = conn.prepareStatement(sql);
        res = prepStmt.executeQuery();
        while(res.next()){
            String word = res.getString(1);
            int count = res.getInt(2);
            System.out.println(word + ", " +count);
        }
        res.close();
        prepStmt.close();
        conn.close();
    }
}

运行...

没有报任何错误.

然后前面设置端口,在前台的运行的标签页中运行MR....

要把这个放在服务任务放在后台执行:

要用到Linux中的nohup