1、问题描述：
（1）问题示例：
[Hadoop@master TestDir]$ sqoop import --connect jdbc:mysql://master:3306/source?useSSL=false --username Hive --password ****** --table customer --hive-import --hive-table rds.customer --hive-overwrite
2021-11-05 20:13:59,638 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7
2021-11-05 20:13:59,664 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
2021-11-05 20:13:59,665 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
2021-11-05 20:13:59,665 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
2021-11-05 20:13:59,743 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
2021-11-05 20:13:59,748 INFO tool.CodeGenTool: Beginning code generation
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
2021-11-05 20:14:00,022 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `customer` AS t LIMIT 1
2021-11-05 20:14:00,369 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `customer` AS t LIMIT 1
2021-11-05 20:14:00,377 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/grid/Hadoop/hadoop-3.3.1
......(此处有省略)
2021-11-05 20:15:51,825 INFO mapreduce.ImportJobBase: Transferred 807 bytes in 102.2706 seconds (7.8908 bytes/sec)
2021-11-05 20:15:51,828 INFO mapreduce.ImportJobBase: Retrieved 14 records.
2021-11-05 20:15:51,828 INFO mapreduce.ImportJobBase: Publishing Hive/Hcat import job data to Listeners for table customer
2021-11-05 20:15:51,847 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `customer` AS t LIMIT 1
2021-11-05 20:15:52,005 INFO hive.HiveImport: Loading uploaded data into Hive
2021-11-05 20:15:52,009 ERROR hive.HiveConfig: Could not load org.apache.hadoop.hive.conf.HiveConf. Make sure HIVE_CONF_DIR is set correctly.
2021-11-05 20:15:52,010 ERROR tool.ImportTool: Import failed: java.io.IOException: java.lang.ClassNotFoundException: org.apache.hadoop.hive.conf.HiveConf
at org.apache.sqoop.hive.HiveConfig.getHiveConf(HiveConfig.java:50)
at org.apache.sqoop.hive.HiveImport.getHiveArgs(HiveImport.java:392)
at org.apache.sqoop.hive.HiveImport.executeExternalHiveScript(HiveImport.java:379)
at org.apache.sqoop.hive.HiveImport.executeScript(HiveImport.java:337)
at org.apache.sqoop.hive.HiveImport.importTable(HiveImport.java:241)
at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:537)
at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:628)
at org.apache.sqoop.Sqoop.run(Sqoop.java:147)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243)
at org.apache.sqoop.Sqoop.main(Sqoop.java:252)
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.hive.conf.HiveConf
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.sqoop.hive.HiveConfig.getHiveConf(HiveConfig.java:44)
... 12 more
（2）问题综述：
问题核心所在：上述示例标红部分，即：
2021-11-05 20:15:52,009 ERROR hive.HiveConfig: Could not load org.apache.hadoop.hive.conf.HiveConf. Make sure HIVE_CONF_DIR is set correctly.
2021-11-05 20:15:52,010 ERROR tool.ImportTool: Import failed: java.io.IOException: java.lang.ClassNotFoundException: org.apache.hadoop.hive.conf.HiveConf
上述显示：存在两个问题。
2、问题剖析：
（1）参考：
参考1：https://www.cnblogs.com/drl-blogs/p/11086865.html
参考2：https://blog.csdn.net/lianghecai52171314/article/details/104454332
（2）根据参考资料和问题示例报错部分，进行分析和排查：
对于问题1：“ERROR hive.HiveConfig: Could not load org.apache.hadoop.hive.conf.HiveConf. Make sure HIVE_CONF_DIR is set correctly.”，推测是HIVE环境未配置好，找不到环境变量HIVE_CONF_DIR，尤其是Hive中的jar工具库。出现示例问题的报错是可能的，存在未正确配置好环境变量HIVE_CONF_DIR而导致该种问题的可能性。但是根据笔者Hive正常使用情况，以及从最终正确结果反推，出现该种错误不是根本原因。笔者亲测验证，各种设置改环境变量值，都未排除示例问题。
对于问题2：“ERROR tool.ImportTool: Import failed: java.io.IOException: java.lang.ClassNotFoundException: org.apache.hadoop.hive.conf.HiveConf”，是导致示例问题报错出现的根本原因。笔者根据参考资料——参考2，进行排雷，求得正解。
示例报错的原因是：
Sqoop工具缺少了hive-common-*.*.*.jar，将Hive的lib目录下的hive-common-3.1.2.jar拷贝至Sqoop的lib目录下即可。
3、解决方案：
方案1：错误排雷
（1）问题排查：查看Hive安装路径下lib中的hive-common-*.*.*.jar中是否还有类“HiveConf.class”。
[Hadoop@master lib]$ ls hive-common*
hive-common-3.1.2.jar
[Hadoop@master lib]$ jar tf hive-common-3.1.2.jar | grep HiveConf.class
org/apache/hadoop/hive/conf/HiveConf.class
从上面结果可知，Hive安装路径lib中是存在Hive-common-*.jar工具。
（2）配置环境，将hive安装路径lib添加至hadoop环境HADOOP_CLASSPATH中。
此法未解决笔者本示例的问题，但存在引起该示例问题的可能性（笔者未验证）。
方案2：正确排雷
（1）拷贝hive-common-3.1.2.jar
将Hive的lib目录下的hive-common-3.1.2.jar拷贝至Sqoop的lib目录下即可。
（2）二次测试：看到下面最后1行，即说明解决了示例问题，Sqoop成功将MySQL全覆盖传入Hive数据库中。
[Hadoop@master TestDir]$ sqoop import --connect jdbc:mysql://master:3306/source?useSSL=false --username Hive --password ******* --table customer --hive-import --hive-table rds.customer --hive-overwrite
2021-11-06 00:41:17,492 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7
2021-11-06 00:41:17,516 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
2021-11-06 00:41:17,516 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
2021-11-06 00:41:17,516 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
2021-11-06 00:41:17,579 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
2021-11-06 00:41:17,584 INFO tool.CodeGenTool: Beginning code generation
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
2021-11-06 00:41:17,831 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `customer` AS t LIMIT 1
2021-11-06 00:41:17,874 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `customer` AS t LIMIT 1
2021-11-06 00:41:17,880 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/Hadoop/Hadoop/hadoop-3.3.1
......(此处有省略)
2021-11-06 00:42:20,755 INFO hive.HiveImport: OK
2021-11-06 00:42:20,756 INFO hive.HiveImport: 2021-11-06 00:42:20,755 INFO [40671dec-9d11-4d68-b514-9df6685af945 main] ql.Driver (SessionState.java:printInfo(1227)) - OK
2021-11-06 00:42:20,756 INFO hive.HiveImport: 2021-11-06 00:42:20,755 INFO [40671dec-9d11-4d68-b514-9df6685af945 main] lockmgr.DbTxnManager (DbTxnManager.java:stopHeartbeat(846)) - Stopped heartbeat for query: grid_20211106004218_3df662fa-e868-477a-a8db-eb11ce9534fe
2021-11-06 00:42:20,854 INFO hive.HiveImport: Time taken: 2.147 seconds
2021-11-06 00:42:20,855 INFO hive.HiveImport: 2021-11-06 00:42:20,854 INFO [40671dec-9d11-4d68-b514-9df6685af945 main] CliDriver (SessionState.java:printInfo(1227)) - Time taken: 2.147 seconds
2021-11-06 00:42:20,855 INFO hive.HiveImport: 2021-11-06 00:42:20,855 INFO [40671dec-9d11-4d68-b514-9df6685af945 main] conf.HiveConf (HiveConf.java:getLogIdVar(5040)) - Using the default value passed in for log id: 40671dec-9d11-4d68-b514-9df6685af945
2021-11-06 00:42:20,856 INFO hive.HiveImport: 2021-11-06 00:42:20,855 INFO [40671dec-9d11-4d68-b514-9df6685af945 main] session.SessionState (SessionState.java:resetThreadName(452)) - Resetting thread name to main
2021-11-06 00:42:20,856 INFO hive.HiveImport: 2021-11-06 00:42:20,856 INFO [main] conf.HiveConf (HiveConf.java:getLogIdVar(5040)) - Using the default value passed in for log id: 40671dec-9d11-4d68-b514-9df6685af945
2021-11-06 00:42:20,907 INFO hive.HiveImport: 2021-11-06 00:42:20,905 INFO [main] session.SessionState (SessionState.java:dropPathAndUnregisterDeleteOnExit(885)) - Deleted directory: /user/hive/tmp/grid/40671dec-9d11-4d68-b514-9df6685af945 on fs with scheme hdfs
2021-11-06 00:42:20,907 INFO hive.HiveImport: 2021-11-06 00:42:20,906 INFO [main] session.SessionState (SessionState.java:dropPathAndUnregisterDeleteOnExit(885)) - Deleted directory: /tmp/hive/Local/40671dec-9d11-4d68-b514-9df6685af945 on fs with scheme file
2021-11-06 00:42:20,907 INFO hive.HiveImport: 2021-11-06 00:42:20,906 INFO [main] metastore.HiveMetaStoreClient (HiveMetaStoreClient.java:close(600)) - Closed a connection to metastore, current connections: 1
2021-11-06 00:42:21,038 INFO hive.HiveImport: Hive import complete.
