StreamSets converting Text to Json

Question

I am trying to ingest text data from local directory to HDFS, before ingesting i need to convert text into valid json. For that, i am using JavaScript Evaluator processor.

In javascript evaluator i unable to read any record.

Here is my sample code:

for(var i = 0; i < records.length; i++) {
 try {  
   output.write(records[i]);
 } catch (e) {
   error.write(records[i], e);
 }
}

Is any other better option other than JavaScript evaluator?

Here is my sample input data:

{
    1046=
    1047=
    1048=5324800
    1049=20180508194648
    1095=2297093400,
    1111=up_default
    1118=01414011002101251
    1139=1
}
{
    1140=1
    1176=mdlhggsn01_1.mpt.com;3734773893;2472;58907
    1183=4
    1211=07486390
    1214=0
    1227=51200
    1228=111
    1229=0
    1250=614400,
}

UPDATE:

As per @metadaddy's answer, i try to use Groovy insted of JavaScript. I am getting following exception for the same data that @metadaddy showed in his answer.

Here is my error screenshot.

Answer 1

Your JavaScript needs to read through the input, building output records.

Using Text format, the Directory origin will create a record with a /text field for each line of input.

This JavaScript will build the record structure you need:

for(var i = 0; i < records.length; i++) {
  try {
    // Start of new input record
    if (records[i].value.text.trim() === '{') {
      // Use starting input record as output record
      // Save in state so it persists across batches
      state.outRecord = records[i];
      // Clean out the value
      state.outRecord.value = {};
      // Move to next line
      i++;
      // Read values to end of input record
      while (i < records.length && records[i].value.text.trim() !== '}') {
        // Split the input line on '='
        var kv = records[i].value.text.trim().split('=');
        // Check that there is something after the '='
        if (kv[1].length > 0) {
          state.outRecord.value[kv[0]] = kv[1];   
        } else if (kv[0].length > 0) {
          state.outRecord.value[kv[0]] = NULL_STRING;
        }
        // Move to next line of input
        i++;
      }

      // Did we hit the '}' before the end of the batch?
      if (i < records.length) {
        // Write record to processor output
        output.write(state.outRecord);
        log.debug('Wrote a record with {} fields', 
            Object.keys(state.outRecord.value).length);
        state.outRecord = null;        
      }
    }
  } catch (e) {
    // Send record to error
    log.error('Error in script: {}', e);
    error.write(records[i], e);
  }
}

Here is a preview of the transformation on your sample input data:

Now, to write the entire record to HDFS as JSON, simply set the Data Format in the Hadoop FS destination to JSON.

Answer 2

Groovy script in StreamSets Data Collector executes much faster than JavaScript, so here is the same solution in Groovy.

Using Text format, the Directory origin will create a record with a /text field for each line of input.

This script will build the record structure you need:

for (i = 0; i < records.size(); i++) {
  try {
    // Start of new input record
    if (records[i].value['text'].trim() == "{") {
      // Use starting input record as output record
      // Save in state so it persists across batches
      state['outRecord'] = records[i]
      // Clean out the value
      state['outRecord'].value = [:]
      // Move to next line
      i++
      // Read values to end of input record
      while (i < records.size() && records[i].value['text'].trim() != "}") {
        // Split the input line on '='
        def kv = records[i].value['text'].trim().split('=')
        // Check that there is something after the '='
        if (kv.length == 2) {
          state['outRecord'].value[kv[0]] = kv[1]
        } else if (kv[0].length() > 0) {
          state['outRecord'].value[kv[0]] = NULL_STRING
        }
        // Move to next line of input
        i++
      }

      // Did we hit the '}' before the end of the batch?
      if (i < records.size()) {
        // Write record to processor output
        output.write(state['outRecord'])        
        log.debug('Wrote a record with {} fields', 
            state['outRecord'].value.size());
        state['outRecord'] = null;        
      }
    }
  } catch (e) {
    // Write a record to the error pipeline
    log.error(e.toString(), e)
    error.write(records[i], e.toString())
  }
}

Running this on input data:

{
    1=959450992837
    2=95973085229
    3=1525785953
    4=29
    7=2
    8=
    9=
    16=abd
    20=def
    21=ghi;jkl
    22=a@b.com
    23=1525785953
    40=95973085229
    41=959450992837
    42=0
    43=0
    44=0
    45=0
    74=1
    96=1
    98=4
    99=3
}

Gives output:

{
  "1": "959450992837",
  "2": "95973085229",
  "3": "1525785953",
  "4": "29",
  "7": "2",
  "8": null,
  "9": null,
  "16": "abd",
  "20": "def",
  "21": "ghi;jkl",
  "22": "a@b.com",
  "23": "1525785953",
  "40": "95973085229",
  "41": "959450992837",
  "42": "0",
  "43": "0",
  "44": "0",
  "45": "0",
  "74": "1",
  "96": "1",
  "98": "4",
  "99": "3"
}