在使用 JDBC 开发 Hive 程序时, 必须首先开启 Hive 的远程服务接口。使用下面命令进行开启:
$HIVE_HOME/bin/hiveserver2 OR hive -service hiveserver2 & #注意，1.0版本以后，用的是hiveserver2
hive server 1的driver classname是org.apache.hadoop.hive.jdbc.HiveDriver，
Hive Server 2的是org.apache.hive.jdbc.HiveDriver，这两个容易混淆。
1). 测试数据
userinfo.txt文件内容(每行数据之间用tab键隔开):
1 xiapi 2 xiaoxue 3 qingqing
2). 程序代码
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;
public class HiveClient {
//hive1为 org.apache.hadoop.hive.jdbc.HiveDriver
private static String driverName = "org.apache.hive.jdbc.HiveDriver";
private static String url = "jdbc:hive2://192.168.163.110:10000/default"; //注意和hive1的区别
private static String user = "hive";
private static String password = "mysql";
private static String sql = "";
private static ResultSet res;
//private static final Logger log = Logger.getLogger(HiveJdbcClient.class);
public static void main(String[] args) {
try {
Class.forName(driverName);
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
// 创建的表名
String tableName = "testHiveDriverTable";
// 第一步:存在就先删除
sql = "drop table " + tableName;
stmt.executeQuery(sql);
// 第二步:不存在就创建
sql = "create table " + tableName + " (key int, value string) row format delimited fields terminated by ' '
stmt.executeQuery(sql);
// 执行“describe table”操作
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) + " " + res.getString(2));
}
// 执行“load data into table”操作
String filepath = "/home/hadoop/ziliao/userinfo.txt";
sql = "load data local inpath " + filepath + " into table " + tableName;
System.out.println("Running:" + sql);
res = stmt.executeQuery(sql);
// 执行“select * query”操作
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) + " " + res.getString(2));
}
// 执行“regular hive query”操作, 执行错误时，注意看hiveserver2的输出结果
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(res.getString(1));
}
conn.close();
conn = null;
} 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);
}
}
}
3). 运行结果(右击-->Run as-->Run on Hadoop)
Running:show tables testHiveDriverTable
执行“show tables”运行结果:
testhivedrivertable
Running:describe testHiveDriverTable
执行“describe table”运行结果:
key int
value string
Running:load data local inpath /home/hadoop/ziliao/userinfo.txt into table testHiveDriverTable
Running:select * from testHiveDriverTable
执行“select * query”运行结果:
xiapi
xiaoxue
qingqing
Running:select count(1) from testHiveDriverTable
执行“regular hive query”运行结果: