UDJC-process input, then output

[kibear]

Hi everybody:
In UDJC sample, the output field append after the input field, like input field a, output create a new field b, finally output include a,b.
Is there any way do this: just output field b, exclude input field, someone tell me just modify outputRowMeta, but i dont know how to do this.

[hansva]

Let's take a step back. What are you trying to achieve that requires the UDJC transform?
Why not use the regular transforms to do what you are trying to do?

Using the UDJC transform is usually a last resort when you want to do something very special that the application doesn't allow, and you will need to know how the internals of Hop work.

[kibear]

Someone has developed some transform method use java, I invoke their method make transfrom, then save output. I know put new field after input field is also fine, but i just want to output new field to next step.

[bamaer]

also (like I suggested in #6001), if you really need to use UDJC, take a look at transforms/user-defined-java-class-calculate-date-of-easter.hpl in the samples project.

[kibear]

Yes，i have looked it, but i also do not know how to do it,i wanna just output new field product in udjc.

[dave-csc]

Strictly answering your question, you just need to set the flag Clear the result fields? in the UDJC transform interface: this way (all) the input fields will be stripped from the stream, and replaced with those you generate in the transform.

Hope this helps :)

[hansva]

As the UDJC transform implements the same code as any other transform in Hop you can also look at another transform that manipulates fields. for example you can look at the select values code to see how it is handled

[kibear]

When use get(Fields.Out, "dt").setValue(outputRow , "dt"); not work!
Only use index set value work:
IRowMeta outputRowMeta = new RowMetaBuilder()
.addString("dt").addString("full_code")
.addNumber("DsptPwr").addNumber("NacVibY")
.addNumber("NacExtTemp").addNumber("AxCtrlCabTemp2")
.addInteger("WdSpd").build();
Object[] outputRow = new Object[outputRowMeta.size()];
outputRow[0] = dt;
outputRow[1] = dev_code;
outputRow[2] = DsptPwr;
outputRow[3] = NacVibY;
outputRow[4] = NacExtTemp;
outputRow[5] = AxCtrlCabTemp2;
outputRow[6] = WdSpd;

putRow(outputRowMeta, outputRow);