Hive的访问接口
Hive提供了三种客户端访问接口：
1）Hive CLI（Hive Command Line，Hive命令行），客户端可以直接在命令行模式下进行操作。
2）hwi（Hive Web Interface，Hive Web接口），Hive提供了更直观的Web界面
3）hiveserver，Hive提供了Thrift服务，Thrift客户端目前支持C++/Java/PHP/Python/Ruby。
下面我们来分别尝试下这三种接口访问方式：
一、Hive CLI
直接键入hive命令即可进入CLI模式：
[ cloud@cloud01 lib ] $ hive Hive history file = /tmp/ cloud / hive_job_log_cloud_201110311056_1009535967 . txt hive & gt ; show tables ; OK testhivedrivertable Time taken : 3.038 seconds hive & gt ; select * from testhivedrivertable ; OK Time taken : 0.905 seconds hive & gt ; quit ; [ cloud@cloud01 lib ] $更多的命令选项，参见官方wiki， Hive Cli
二、Hive hwi
Hive hwi提供了一个更直观的web界面，使用起来更方便。
1）启动hive hwi
[ cloud@cloud01 ~] $ hive -- service hwi 11 / 10 / 31 10 : 14 : 11 INFO hwi . HWIServer : HWI is starting up 11 / 10 / 31 10 : 14 : 11 INFO mortbay . log : Logging to org . slf4j . impl . Log4jLoggerAdapter ( org . mortbay . log ) via org . mortbay . log . Slf4jLog 11 / 10 / 31 10 : 14 : 11 INFO mortbay . log : jetty - 6.1 . 14 11 / 10 / 31 10 : 14 : 11 INFO mortbay . log : Extract jar : file : /data/ cloud / hive - 0.7 . 1 / lib / hive - hwi - 0.7 . 1.war ! / to / tmp / Jetty_0_0_0_0_9999_hive . hwi . 0.7 . 1.war __hwi__ . hf8ccz / webapp 11 / 10 / 31 10 : 14 : 12 INFO mortbay . log : Started SocketConnector@0 . 0.0 . 0 : 99992）通过hwi方式访问Hive
我的Hive部署在10.46.169.101机器上，hive默认hwi端口为9999。我们在浏览器中键入 http://10.46.169.101:9999/hwi/ 就可以访问了。如图：
更多hwi的信息，访问官方wiki， hwi
三、hiveserver
Hive以Thrift方式作为服务对客户端提供，目前Hive的Thrift绑定了多种语言，C++/Java/PHP/Python/Ruby，可在Hive发行版本的src/service/src目录下找到这些语言的Thrift绑定。Hive还提供了JDBC和ODBC的驱动，大大方面了基于Hive的应用开发。我利用官方的例子对JDBC驱动进行了测试。
1）启动hiveserver
[ cloud@cloud01 ~] $ hive -- service hiveserver Starting Hive Thrift Server2）在Eclipse中新建一个Java工程Hive0.7.1Test
3）将$HIVE_HOME/lib目录下的jar包加到工程的buildpath里
4）Hive的表是存储在HDFS上，所以，需要加载Hadoop的核心jar包。我的Hadoop版本是0.20.1。
5）新建一个class，用官方wiki提供的代码，如下：
import java . sql . SQLException ; import java . sql . Connection ; import java . sql . ResultSet ; import java . sql . Statement ; import java . sql . DriverManager ; public class HiveJdbcClient { private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver" ; /** * @param args * @throws SQLException */ public static void main ( String [] args ) throws SQLException { try { Class . forName ( driverName ); } catch ( ClassNotFoundException e ) { // TODO Auto-generated catch block e . printStackTrace (); System . exit ( 1 ); } Connection con = DriverManager . getConnection ( "jdbc:hive://10.46.169.101:10000/default" , "" , "" ); Statement stmt = con . createStatement (); String tableName = "testHiveDriverTable" ; stmt . executeQuery ( "drop table " + tableName ); ResultSet res = stmt . executeQuery ( "create table " + tableName + " (key int, value string)" ); // show tables String sql = "show tables '" + tableName + "'" ; System . out . println ( "Running: " + sql ); res = stmt . executeQuery ( sql ); if ( res . next ()) { System . out . println ( res . getString ( 1 )); } // describe table sql = "describe " + tableName ; System . out . println ( "Running: " + sql ); res = stmt . executeQuery ( sql ); while ( res . next ()) { System . out . println ( res . getString ( 1 ) + "\t" + res . getString ( 2 )); } // load data into table // NOTE: filepath has to be local to the hive server // NOTE: /tmp/a.txt is a ctrl-A separated file with two fields per line String filepath = "/tmp/a.txt" ; sql = "load data local inpath '" + filepath + "' into table " + tableName ; System . out . println ( "Running: " + sql ); res = stmt . executeQuery ( sql ); // select * query sql = "select * from " + tableName ; System . out . println ( "Running: " + sql ); res = stmt . executeQuery ( sql ); while ( res . next ()) { System . out . println ( String . valueOf ( res . getInt ( 1 )) + "\t" + res . getString ( 2 )); } // regular hive query sql = "select count(1) from " + tableName ; System . out . println ( "Running: " + sql ); res = stmt . executeQuery ( sql ); while ( res . next ()) { System . out . println ( res . getString ( 1 )); } } }6）编译运行，console如下：<div> 2011-10-31 11:21:31,703 WARN [main] conf.Configuration(175): DEPRECATED: hadoop-site.xml found in the classpath. Usage of hadoop-site.xml is deprecated. Instead use core-site.xml, mapred-site.xml and hdfs-site.xml to override properties of core-default.xml, mapred-default.xml and hdfs-default.xml respectively </div> <div> Running: show tables 'testHiveDriverTable' </div> <div> testhivedrivertable </div> <div> Running: describe testHiveDriverTable </div> <div> keyint </div> <div> valuestring </div> <div> Running: load data local inpath '/tmp/a.txt' into table testHiveDriverTable </div> <div> Exception in thread "main" java.sql.SQLException: Query returned non-zero code: 10, cause: FAILED: Error in semantic analysis: Line 1:23 Invalid path '/tmp/a.txt': No files matching path file:/tmp/a.txt </div> <div> at org.apache.hadoop.hive.jdbc.HiveStatement.executeQuery(HiveStatement.java:192) </div> <div> at com.zte.allen.hive.HiveJdbcClient.main(HiveJdbcClient.java:53) </div>报了一个Exception，是因为加载源是找不到/tmp/a.txt。这个不影响，但可以从hwi里看到已经新建了一个表testhivedrivertable。更多关于hiveserver的内容，参见官方wiki Setting up Hive Server , 还有 这里 介绍了各种客户端（cli、Java、PHP、Python、ODBC、Thrift方式等）如何访问Hive。
