Hive用户自定义函数UDF

    1：  hive用户自定义函数udf，实现对字符串的格式化操作

    引入maven依赖：

<dependency>
        <groupId>commons-lang</groupId>
        <artifactId>commons-lang</artifactId>
        <version>2.6</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>3.1.0</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.hive/hive-exec -->
    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-exec</artifactId>
        <version>3.0.0</version>
    </dependency>

package com.hadoop.hive;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;
public class MyUdf extends UDF {
    private  Text resoult=new Text();
    //去除字符串text前后空字符
    public Text evaluate(Text text){
        if (text==null){
            return null;
        }
        resoult.set(StringUtils.strip(text.toString()));
        return resoult;
    }
    //去除字符串text尾在st中出现的字符
    public Text evaluate(Text text,String st){
        if (text==null){
            return null;
        }
        resoult.set(StringUtils.strip(text.toString(),st));
        return resoult;
    }
}

HiveQL操作:https://blog.csdn.net/qq_34696236/article/details/81385770