Hive UDF

Hive

创建maven工程

pom.xml添加依赖包

<!-- Hive Client -->
<dependency>
    <groupId>org.apache.hive</groupId>
    <artifactId>hive-jdbc</artifactId>
    <version>${hive.version}</version>
</dependency>
<dependency>
    <groupId>org.apache.hive</groupId>
    <artifactId>hive-exec</artifactId>
    <version>${hive.version}</version>
</dependency>

继承UDF类

实现evaluate方法

package bigdata.hadoop.hive.bigdata.hadoop.hive.udf;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;
public class RemoveQuotes extends UDF{
    public Text evaluate(Text inputValue){
        return new Text();
    }
}

导出jar

jar包加载到hive

hive (testdb)> add jar /opt/datas/udf_removequotes.jar;
Added /opt/datas/udf_removequotes.jar to class path
Added resource: /opt/datas/udf_removequotes.jar

注册udf

hive (testdb)> create temporary function zc_removequotes as 'bigdata.hadoop.hive.bigdata.hadoop.hive.udf.RemoveQuotes';
OK
Time taken: 0.011 seconds

测试

code

package bigdata.hadoop.hive.bigdata.hadoop.hive.udf;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;
public class RemoveQuotes extends UDF{
    public Text evaluate(Text inputValue){
        if(null == inputValue){
            return null;
        }
        if(StringUtils.isBlank(inputValue.toString())){
            return null;
        }
        String str = inputValue.toString();
        String reStr = str;
        if(str.length()>1){
            if ("\"".equals(str.substring(0,1))) {
                reStr = reStr.substring(1);
            }
            if ("\"".equals(str.substring(str.length()-1))) {
                reStr = reStr.substring(0,reStr.length()-1);
            }
        }
        return new Text(reStr);
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(new RemoveQuotes().evaluate(new Text("\"1\"")));
    }
}

在此输入正文