[大数据]udtf自定义函数

package hive;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDTF;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

import java.util.ArrayList;
import java.util.List;

/*
表生成函数
 */
public class MyUDTF extends GenericUDTF {
    @Override
    public StructObjectInspector initialize(ObjectInspector[]
                                                    argOIs) throws UDFArgumentException {
        //定义要输出列的名字的List,并且添加要输出的列名
        List<String> structFieldNames = new ArrayList<>();
        structFieldNames.add("key");
        structFieldNames.add("value");
// 定义要输出列的类型的List,并且添加要输出列的类型
        List<ObjectInspector> objectInspectorList = new
                ArrayList<>();

        Object ingObjectInspector;
        objectInspectorList.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);

        objectInspectorList.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
        return
                ObjectInspectorFactory.getStandardStructObjectInspector(structFieldNames, objectInspectorList);
    }
    /*
    核心处理方法
     */
    @Override
    public void process(Object[] objects) throws HiveException {
        // 得到第?个参数,转化为字符串,类似于->name:zhang;age:30;address:shenzhen
        String insputString = objects[0].toString();
        // 把上述例?字符串按照分号;切分为数组
        String[] split = insputString.split(";");
        // s=name:zhang
        for (String s : split) {
            // 把每个切分后的key value分开
            String[] kvArray = s.split(":");
            // 如果产?多列可以将多个列的值放在?个数组中，然后将该数组传?到forward()函数。
            forward(kvArray);
        }

    }
    //关闭对象
    @Override
    public void close() throws HiveException {

    }
}

参照hive自定义类配置pom.xml