如何在 Pentaho 中完全删除用户定义 Java Class 中的特定输入字段

Question

我不明白在 Pentaho 数据中使用 用户定义 Java Class 时如何完全删除特定输入字段积分.

假设我有输入字段 A、B 和 C。假设我想连接 B 和 C 中的值（由 space 分隔），将结果写入 C，仅保留名称为 A 和 C 的字段，不保留名称为 [=17= 的字段]B（实际问题要复杂得多）。我知道如何在字段 C 中写入结果，但我不知道如何完全删除字段 B.

private String outFieldName1;
private String outFieldName2;
private String removeFieldName;

private int outFieldIndex1;
private int outFieldIndex2;
private int removeFieldIndex;

private Object[] inputRow;

private int inputRowMetaSize;
private int outputRowMetaSize;

public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException
{
    inputRow = getRow();
    if (inputRow == null) {
        setOutputDone();
        return false;
    }

    if (first) processMetadata();

    pushOutputRow( get(Fields.In, removeFieldName).getString(inputRow) + " "
                 + get(Fields.In, outFieldName2).getString(inputRow));

    return true;
}

private void processMetadata() throws KettleException {
    outFieldName1 = getParameter("OUT1");
    outFieldName2 = getParameter("OUT2");
    removeFieldName = getParameter("REMOVE");

    outFieldIndex1 = getInputRowMeta().indexOfValue(outFieldName1);
    outFieldIndex2 = getInputRowMeta().indexOfValue(outFieldName2);
    removeFieldIndex = getInputRowMeta().indexOfValue(removeFieldName);

    inputRowMetaSize = data.inputRowMeta.size();
    outputRowMetaSize = data.outputRowMeta.size();

    first=false;
}


private void pushOutputRow(String content) throws KettleException {
    Object[] outRow = RowDataUtil.allocateRowData(outputRowMetaSize);

    for (int fieldN=0; fieldN < inputRow.length; ++fieldN) {
        if(fieldN == outFieldIndex1) {
            outRow[fieldN] = inputRow[fieldN];
        } else if(fieldN == outFieldIndex2) {
            outRow[fieldN] = content;
        } else if(fieldN == removeFieldIndex) {
            outRow[fieldN] = "";
            // Unable to delete this row!
        }

    }

    putRow( data.outputRowMeta, outRow );
}

Answer 1

只需要：

将 data.outputRowMeta 保存在 RowMetaInterface 类型的变量中（在我的例子中 rowMeta）；
使用要删除的字段的名称或索引调用rowMeta.removeValueMeta方法；
使用rowMeta而不是getInputRowMeta();
在putRow()方法中，使用rowMeta作为第一个参数。

``

private String outFieldName1;
private String outFieldName2;
private String removeFieldName;

private int outFieldIndex1;
private int outFieldIndex2;

private Object[] inputRow;

private int inputRowMetaSize;
private int outputRowMetaSize;
private RowMetaInterface rowMeta;

public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException
{
    inputRow = getRow();
    if (inputRow == null) {
        setOutputDone();
        return false;
    }

    if (first) processMetadata();

    pushOutputRow( get(Fields.In, removeFieldName).getString(inputRow) + " "
                 + get(Fields.In, outFieldName2).getString(inputRow));

    return true;
}

private void processMetadata() throws KettleException {
    outFieldName1 = getParameter("OUT1");
    outFieldName2 = getParameter("OUT2");
    removeFieldName = getParameter("REMOVE");

    inputRowMetaSize = data.inputRowMeta.size();
    outputRowMetaSize = data.outputRowMeta.size();

    rowMeta = data.outputRowMeta;
    rowMeta.removeValueMeta(removeFieldName);

    outFieldIndex1 = rowMeta.indexOfValue(outFieldName1);
    outFieldIndex2 = rowMeta.indexOfValue(outFieldName2);

    outputRowMetaSize = rowMeta.size();

    first=false;
}

private void pushOutputRow(String content) throws KettleException {
    Object[] outRow = RowDataUtil.allocateRowData(outputRowMetaSize);

    for (int fieldN=0; fieldN < inputRow.length; ++fieldN) {

        if(fieldN == outFieldIndex1) {
            outRow[fieldN] = inputRow[fieldN];
        } else if(fieldN == outFieldIndex2) {
            outRow[fieldN] = content;
        }
    }

    putRow( rowMeta, outRow );
}

``

如何在 Pentaho 中完全删除用户定义 Java Class 中的特定输入字段

How to completely remove specific input fields in User Defined Java Class in Pentaho

java

pentaho-data-integration