Java 调用Hive 自定义UDF

注： 转自 http://blog.csdn.net/allen_oscar/article/details/45146913

• Hive 具有一个可选的组件叫做HiveServer,它允许通过在一定的端口访问hive.
  将自定义的UDF的jar拷贝到安装的hive服务器中（如 /home/Hadoop下）
  具体的不啰嗦了，看代码吧！

package com.hive.client;  import java.sql.Connection;  import java.sql.DriverManager;  import java.sql.ResultSet;  import java.sql.SQLException;  import java.sql.Statement;  public class HiveClientUDF {      private static String driverName = "org.apache.hive.jdbc.HiveDriver";      private static String url = "jdbc:hive2://192.168.150.162:10000/default";      private static String sql = "";      private static ResultSet res;      public static void main(String[] args) throws SQLException, ClassNotFoundException {          // TODO Auto-generated method stub           Connection conn = null;           Class.forName(driverName);           //默认使用端口10000, 使用默认数据库，用户名密码默认  hadoop 服务器登录用户名  dh!123456登录密码           conn = DriverManager.getConnection(url, "hadoop", "dh！123456");           String tableName = "vehicle_pass";           Statement stmt = conn.createStatement();           //将cityudf.jar加入到HIVE类路径下           sql = "add jar /home/hadoop/cityudf.jar";           stmt.execute(sql);           //加入到classpath下           sql = "create temporary function cityudf as 'com.hive.utf.CityUDF'";           stmt.execute(sql);           //使用自定义UDF cityudf           sql = "select  key,kkNO,cityudf(key) as city 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.getString(1) + "\t" +":" + res.getString(3));            }             stmt.close();            conn.close();        }  }  

• 运行结果：

1522301_20150417103242404_黑A01BCI   :哈尔滨  1522301_20150417103242494_黑A013AA   :哈尔滨  1522301_20150417103242614_黑A01GHI   :哈尔滨  1522301_20150417103242616_黑A01GLJ   :哈尔滨  1522301_20150417103242617_黑A01E5G   :哈尔滨  1522301_20150417103242623_黑A01HDK   :哈尔滨  1522301_20150417103242625_黑A018MM   :哈尔滨  1522301_20150417103242758_黑A015KD   :哈尔滨