CODEWITHSUNDEEP
gradlegroovy
Colin
Colin

Reputation: 41

Groovy println prints empty string to console instead of the proper string

I'm parsing output for a test I'm running as a Gradle JavaExec task. I want to filter the output so that only errors are shown in stdout (I'm running the task from the Windows command line).

In a doLast{} block, I've parsed the OutputStream to a list of strings where each entry is a line:

ByteArrayOutputStream baos = new ByteArrayOutputStream()
String log = baos.toString()
List<String> logLines
logLines = new ArrayList<String>(Arrays.asList(log.split('\n')))

then iterated through the list, printing each line that starts with 'E' (for ERROR):

for (String entry : logLines){
     if (entry.charAt(0) == 'E'){
           println "First char == E"
           println (entry)
     }
}
println "Execution complete!"

My output prints the first two errors, but prints empty strings for all the rest:

First char == E
ERROR More info here
First char == E
ERROR More info here
First char == E

First char == E

First char == E

Execution complete!

Why does println(entry) print empty strings? Obviously entry is not an empty string, because it wouldn't get past the boolean condition if it's first character was empty.

Upvotes: 3

Views: 1221

Answers (1)

Colin
Colin

Reputation: 41

@Roman had the answer: println(groovy.json.JsonOutput.toJson(entry)) revealed that carriage returns \r were being used in addition to new lines \n. Therefore the solution is to split by the regex '[\r\n]+' which will separate into an array of strings at each \n or \r\n

Upvotes: 1

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