我正在研究hiveudtf，以便围绕主键转置每一行。作为需求的一部分，我需要将列名和相应的数据与键相关联。

e.g.
Source Data

Customer_id    Customer_name     Customer_type
1000000        ABCD              Individual

hiveudtf将数据转换为

Key          att_name          att_val
10000000     customer_name     ABCD
10000000     customer_type     Individual

我已经编写了udtf，它正在工作，目前正在生成以下数据

Key          att_name       att_val
10000000     _col0          ABCD
10000000     _col1          Individual

下面是代码 (StructField)inputFields.get(i)).getFieldName() 正在返回\u col0而不是客户\u name。
这可能是apache配置单元中的一个缺陷，或者还有另一个Map将\u col0Map到我应该参考的实际模式。

public class transposeUDTF extends GenericUDTF {

private Map tableMap = new HashMap();
private MetadataListStructObjectInspector metadataDetails;

@Override
public StructObjectInspector initialize(StructObjectInspector args) throws UDFArgumentException {

    List inputFields = args.getAllStructFieldRefs();
    ((StructObjectInspector)args).getTypeName();

    for(int i = 0; i < inputFields.size(); ++i)
    {
        tableMap.put(i+1,((StructField)inputFields.get(i)).getFieldName());

    }

    return super.initialize(args);

}

@Override
public StructObjectInspector initialize(ObjectInspector[] argOIs) throws UDFArgumentException {
    List<String> fieldNames = new ArrayList<String>(3);
    List<ObjectInspector> fieldOIs = new ArrayList<ObjectInspector>(3);
    fieldNames.add("key");
    fieldNames.add("AttrName");
    fieldNames.add("AttrVal");
    fieldOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
    fieldOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
    fieldOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);
    return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs);
}

@Override
public void process(Object[] record) throws HiveException {

    ArrayList<Object[]> results = new ArrayList<Object[]>();

    for(int i = 1; i < record.length; ++i) {
        results.add(new Object[] {record[0],tableMap.get(i).toString(),record[i]});
    }

    Iterator<Object[]> it = results.iterator();

    while (it.hasNext()){
        Object[] r = it.next();
        forward(r);
    }
}

@Override
public void close() throws HiveException {
    // do nothing
}
}