The first example of Hive UDF development

 PackageUDF;ImportOrg.apache.hadoop.hive.ql.exec.UDF; Public classHelloudfextendsudf{ Publicstring Evaluate (String str) {Try {return"HelloWorld" +str;} Catch(Exception e) {//Todo:handle Exceptionreturn NULL;}}} The above is the meaning of a UDF program written by Java project. Everyone should understand packaged as a jar: Before the Fat Jar blog was sent a jar package, and then exported to a jar to the Linux local directory into the Hiveadd jar/home/hadoop/udf_1_fat.jar;//Note that this address is a Linux local address, not an HDFS address that is not received unless you add HDFs links (no tests)CREATE temporary FUNCTION HelloWorld as ' udf.helloudf 'show functions can see all the supported methods, there will be HelloWorld find a table, there is a bit of data in my side looking for a table, I find out the data is: Hive> select * from hive1 limit 10; OK100 Flower Home Zhang Yunlong 18001295207 155 2 Room 1 Hall 1 Wei 94 2/5 floor North and South Sina Hebei chain Home2 China Yuwa small town Gao Wei 13501061874 210 3 Room 2 Hall 1 Wei 115 6/6 Floor North-South Sina Kelly Gate3 Golden Thai City Lai Wan Horse Harvest 18210989857 1200 5 Room 3 Hall 3 Wei 258 18/19-storey north-south Sina 21st century4 Love Day Green Island Yuhongliang 13366126543 430 3 Room 2 Hall 2 Wei 149 2/4-storey north-south Sina such as real estate5 YiHai Garden Hengtai Garden Shransen 18401296028 520 2 Room 2 Hall 2 Wei 136 15/28-storey West Sina I love my family .6 New Town View Yu Park Zhang Super 18910750910 180 2 Room 1 Hall 1 Wei 89 14/18 Floor North-South Sina Morning building Shun house7 dongrunfengjing Jingsun Center source 13501365333 380 2 Room 1 Hall 1 Wei 91 1/20-storey southeast Sina I love my family .8 Beiyuan home Hope Spring Garden Tektronix 18311385981 245 1 Room 1 Hall 1 Wei 69 17/25 floor Southeast Sina City bearing property9 Central Park Plaza Ludehui 15010507970 5800 1 Room 0 Hall 0 Wei 672 2/26 Floor South Sina Huaqing10 City second quarter Yang Yuiping 15001210716 200 4 Room 1 Hall 2 Wei 155 6/15-storey north-south Sina Hebei chain home field that's all we got. Hive is the result.> select HelloWorld (hive1.large) from hive1 limit 10; Okhelloworld94HelloWorld115HelloWorld258HelloWorld149HelloWorld136HelloWorld89HelloWorld91HelloWorld69HelloWorld672HelloWorld155Time taken:0.131 seconds, Fetched:10row (s) Hive> select HelloWorld (hive1.price) from hive1 limit 10; Okhelloworld155HelloWorld210HelloWorld1200HelloWorld430HelloWorld520HelloWorld180HelloWorld380HelloWorld245HelloWorld5800HelloWorld200Time taken:0.111 seconds, Fetched:10row (s) Hive> select HelloWorld (hive1.id) from hive1 limit 10; Okhelloworld1HelloWorld2HelloWorld3HelloWorld4HelloWorld5HelloWorld6HelloWorld7HelloWorld8HelloWorld9HelloWorld10Time taken:0.115 seconds, Fetched:10row (s) OK, everybody knows what it means.

The first example of Hive UDF development