hive Java API

Java连接hive进行操作的方式有多种，接触到了两种：

首先，hive要起动远程服务接口，命令：

hive --service hiveserver -p 50000 &

1. 通过jdbc驱动连接hive

当然还有其他的连接方式，比如ODBC等，这种方式很常用。

不稳定，经常会被大数据量冲挂，不建议使用。

package cn.ac.iscas.hiveclient;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class HiveJDBCClient {

    private static String driverName;
    private static String url;
    private static String user;
    private static String password;

    private Connection conn = null;
    private Statement stmt = null;

    static {
        Properties prop = new Properties();
        InputStream in = HiveJDBCClient.class.getResourceAsStream("hiveCli.properties");
        try{
            prop.load(in);
            driverName = prop.getProperty("driverName");
            url = prop.getProperty("url");
            user = prop.getProperty("user");
            password = prop.getProperty("password");
        }catch (IOException e){
            e.printStackTrace();
        }
    }

    public boolean execute(String sql){
        boolean rs = false;
        try {
            conn = getConn();
            stmt = conn.createStatement();
            rs = stmt.execute(sql);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try{
                if( null != conn){
                    conn.close();
                    conn = null;
                }
                if( null != stmt){
                    stmt.close();
                    stmt = null;
                }
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        return rs;
    }

    public ResultSet executeQuery(String sql){
        ResultSet rs = null;
        try {
            conn = getConn();
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try{
                if( null != conn){
                    conn.close();
                    conn = null;
                }
                if( null != stmt){
                    stmt.close();
                    stmt = null;
                }
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        return rs;
    }

    private static Connection getConn() throws ClassNotFoundException,
    SQLException{
        Class.forName(driverName);
        Connection conn = DriverManager.getConnection(url,user,password);
        return conn;
    }

    public static void main(String[] args){
        HiveJDBCClient hc = new HiveJDBCClient();
        ResultSet rs = hc.executeQuery("desc carsrecord");
        try {
            while(rs.next()){
                System.out.println(rs.getString(1));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

2. 通过hive thrift连接

package cn.ac.iscas.hiveclient;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import org.apache.hadoop.hive.service.HiveClient;
import org.apache.hadoop.hive.service.HiveServerException;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;

public class HiveThreatClient {
    static TTransport transport;
    static TProtocol protocol;
    static HiveClient client ;
    static String ip;
    static int port;

    static {
        Properties prop = new Properties();
        InputStream in = HiveJDBCClient.class.getResourceAsStream("hiveCli.properties");
        try{
            prop.load(in);
            ip = prop.getProperty("ip");
            port = Integer.valueOf(prop.getProperty("port"));
        }catch (IOException e){
            e.printStackTrace();
        }
    }

    public static List<String> execute(String query) throws HiveServerException,
                    TException,TTransportException{
        List<String> result = new ArrayList<String>();
        transport = new TSocket(ip,port);
        protocol = new TBinaryProtocol(transport);
        client = new HiveClient(protocol);
        transport.open();
        client.send_execute(query);
        client.recv_execute();
        //client.send_commit_txn(rqst);
        //client.execute(query);
        List<String> list = client.fetchN(10);
        while(null!=list && list.size()>0){
            for(String r :list){
                System.out.println(r);
                result.add(r);
            }
            list = client.fetchN(10);
        }
        client.shutdown();
        transport.close();
        return result;
    }

    public static void main(String[] args){
        try {
            //HiveThreatClient.execute("desc carsrecord");
            //HiveThreatClient.execute("select distinct addressname from carsrecord  where collectiontime=‘2015-02-02‘");
            //load data inpath ‘/2015/02/2015-02-01.dat‘ overwrite into table carsrecord partition(collectiontime=‘2015-02-01‘)
            for(int i = 10; i < 29; i++){
                String day = i > 9 ? ""+i:"0"+i;
                String stat = "load data inpath ‘/2015/02/2015-02-"+day+".dat‘ overwrite into table carsrecord partition(collectiontime=‘2015-02-"+day+"‘)";
                System.out.println(stat);
                HiveThreatClient.execute(stat);
            }
            //HiveThreatClient.execute("select * from carsrecord where collectiondate>=‘2014-01-01‘ and collectiondate<‘2014-01-03‘");
        } catch (HiveServerException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (TTransportException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (TException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

需要引入的jar包：

•     <classpathentry kind="lib" path="hive-service-0.13.1.jar"/>

      <classpathentry kind="lib" path="hive-exec-0.13.1.jar"/>

      <classpathentry kind="lib" path="slf4j-api-1.6.6.jar"/>

      <classpathentry kind="lib" path="hive-metastore-0.13.1.jar"/>

      <classpathentry kind="lib" path="libfb303-0.9.0.jar"/>