Hive UDF 创建的两个例子

1. 全角到半角的转换

package com.scb.udf;

import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;

public class Full2Half extends UDF {

    public Text evaluate(final Text input) {
        char c[] = input.toString().toCharArray();
        for (int index = 0; index < c.length; index++) {
            if (c[index] == 12288) {// 全角空格
               c[index] = (char) 32;
            } else if (c[index] > 65280 && c[index] < 65375) {// 其他全角字符
                c[index] = (char) (c[index] - 65248);
            }
        }
        return new Text(new String(c));
    }

}

2. Use hdfs file

package com.scb.udf;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.fs.*;
import java.io.*;
import java.util.Properties;

public class HadoopMap extends UDF {

    

    public Text evaluate(final Text input) throws IOException {

        org.apache.hadoop.conf.Configuration conf = new Configuration();
        FileSystem fs = FileSystem.get(conf);
        Path path = new Path("/home/hypers/tmp/test.properties");
        InputStream inputStream = fs.open(path).getWrappedStream();
        Properties properties = new Properties();
        properties.load(inputStream);
        String value = properties.getProperty(input.toString(),"Not Find");
        return new Text(value);
        
    }

}

注册Function

hadoop fs -put -f full2half-1.0-SNAPSHOT.jar  /home/hypers/lib

beeline -u jdbc:hive2://******:10000/ -n hdfs -p ****

create function hadoopmap as 'com.scb.udf.HadoopMap' using jar 'hdfs:///home/hypers/lib/full2half-1.0-SNAPSHOT.jar';

select hadoopmap("Jason");