计算机专业都学什么,北京做网站优化多少钱,做网站UI工具,凯里seo排名优化这里写目录标题 前言1. 新建项目2.配置maven依赖3.编写代码4.打jar包5.上传服务器6.代码中引用 前言
老版本编写UDF时#xff0c;需要继承 org.apache.hadoop.hive.ql.exec.UDF类#xff0c;然后直接实现evaluate()方法即可。 由于公司hive版本比较高#xff08;3.x#x… 这里写目录标题 前言1. 新建项目2.配置maven依赖3.编写代码4.打jar包5.上传服务器6.代码中引用 前言
老版本编写UDF时需要继承 org.apache.hadoop.hive.ql.exec.UDF类然后直接实现evaluate()方法即可。 由于公司hive版本比较高3.x,这次编写UDF就采用了新的版本继承类org.apache.hadoop.hive.ql.udf.generic.GenericUDF实现三个方法
1. 新建项目
打开IDEA新建一个项目基本配置如下Archetype选择图中所示
2.配置maven依赖
导入编写UDF需要用到的依赖
dependencies!-- https://mvnrepository.com/artifact/org.apache.hive/hive-exec --dependencygroupIdorg.apache.hive/groupIdartifactIdhive-exec/artifactIdversion3.1.2/versionexclusionsexclusiongroupIdorg.apache.commons/groupIdartifactIdcommons-compress/artifactId/exclusion/exclusions/dependency
buildpluginsplugingroupIdorg.apache.maven.plugins/groupIdartifactIdmaven-compiler-plugin/artifactIdconfigurationsource8/sourcetarget8/target/configuration/plugin/plugins/build3.编写代码
目录结构可自行定义这块不影响实际功能代码整体框架如下 我这里代码传入三列数据返回一列数据入参可以判断一下是否传入数据正确以及数据类型是否匹配 主要实现三个方法具体内容在代码块中有说明
initializeevaluategetDisplayString
public class ComputeUnitPrice extends GenericUDF {WritableHiveDecimalObjectInspector decimalObjectInspector;//初始化方法做一些检查Overridepublic ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {// 判断输入参数的个数if(arguments.length !3){throw new UDFArgumentLengthException(This UDF Only takes 3 arguments: String, String, Decimal);}ObjectInspector param1 arguments[0];ObjectInspector param2 arguments[1];ObjectInspector param3 arguments[2];// 判断输入参数的类型if(!(param1 instanceof StringObjectInspector)){throw new UDFArgumentException(Param1 Type is error,Must be : String);}if(!(param2 instanceof StringObjectInspector)){throw new UDFArgumentException(Param2 Type is error,Must be : String);}
// if(!(param3 instanceof JavaConstantHiveDecimalObjectInspector)){
// throw new UDFArgumentException(Param3 Type is error,Must be : JavaHiveDecimal);
// }this.decimalObjectInspector (WritableHiveDecimalObjectInspector ) param3;//函数返回值为 Decimal需要返回 Decimal类型的鉴别器对象return PrimitiveObjectInspectorFactory.javaHiveDecimalObjectInspector;}
}Overridepublic Object evaluate(DeferredObject[] arguments) throws HiveException {//计算逻辑编写}//udf的说明Overridepublic String getDisplayString(String[] children) {return ComputeUnitPrice;}//main方法测试一下数据结果public static void main(String[] args) throws HiveException {ComputeUnitPrice computeUnitPrice new ComputeUnitPrice();DeferredObject[] param {new DeferredJavaObject(箱), new DeferredJavaObject(800g*8袋/箱), new DeferredJavaObject(100.20)};JavaDoubleObjectInspector javaDoubleObjectInspector PrimitiveObjectInspectorFactory.javaDoubleObjectInspector;ObjectInspector stringOi PrimitiveObjectInspectorFactory.javaStringObjectInspector;ObjectInspector doubleOi PrimitiveObjectInspectorFactory.javaDoubleObjectInspector;computeUnitPrice.initialize(new ObjectInspector[]{stringOi, stringOi,doubleOi});double res javaDoubleObjectInspector.get(computeUnitPrice.evaluate(param));System.out.println(res res);}4.打jar包
将项目打成jar包
mvn clean package执行完成target目录下寻找自己的jar包
5.上传服务器
本地上传到机器再由机器上传到hdfs或者s3等
6.代码中引用
add jars xxxxx/compute_sku_unit_price.jar;
create temporary function compute_sku_unit_price as xx.xxx.xxx.xxx.ComputeUnitPrice;
${your_sql};
