Hive JDBC运行连接注意事项

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通过jdbc方式连接hive，能让你非常方便、简单地去使用hadoop挖掘数据，门槛大大降低。其实连接方式很简单，但是第一次使用，总会有些莫名奇妙的错误，下面给出一些注意事项，希望对初学者有帮助。

首先我的环境：hadoop2.4.0+hive0.14.0。

所需jar包：

如果你运行程序出现以下错误：

java.io.IOException: HADOOP_HOME or hadoop.home.dir are not set.

java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries.

解决方案：

1、System.setProperty("hadoop.home.dir", "D:/hadoop-2.4.0");

2、下载winutils.exe https://github.com/srccodes/hadoop-common-2.2.0-bin/blob/master/bin/winutils.exe

附上测试代码：

    public class HiveJdbcClient2 {          private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";                        /**           * @param args           * @throws SQLException           */            public static void main(String[] args) throws SQLException {                              System.setProperty("hadoop.home.dir", "D:/hadoop-2.4.0");                            BasicConfigurator.configure();                            try {                    Class.forName(driverName);                } catch (ClassNotFoundException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                    System.exit(1);                }                Connection con = DriverManager.getConnection("jdbc:hive://127.0.0.1:10000/defalt", "","");                Statement stmt = con.createStatement();                              //stmt.executeQuery("drop table test");              stmt.executeQuery("create table if not exists test(amount DOUBLE, st_name string) " +                      "ROW FORMAT DELIMITED " +                      "FIELDS TERMINATED BY '\t' " +                      "STORED AS TEXTFILE");                            //stmt.executeQuery("load data inpath '/user/hive_data/test_data.txt' into table gas");                            long st = System.currentTimeMillis();              ResultSet res = stmt.executeQuery("select st_name,sum(amount) c from test group by st_name  sort by c");                int i=0;              while (res.next()) {                    i++;                  System.out.println(res.getString(1)+" - "+res.getString(2));                }                long en = System.currentTimeMillis();                            System.out.println("总耗时："+(en-st)+"，记录总数："+i);          }       }

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