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ArrayList<String> in PDF from a new row

I want to send some survey in PDF from java, I tryed different methods. I use with StringBuffer and without, but always see text in PDF in one row.
public void writePdf(OutputStream outputStream) throws Exception {
Paragraph paragraph = new Paragraph();
Document document = new Document();
PdfWriter.getInstance(document, outputStream);
document.open();
document.addTitle("Survey PDF");
ArrayList nameArrays = new ArrayList();
StringBuffer sb = new StringBuffer();
int i = -1;
for (String properties : textService.getAnswer()) {
nameArrays.add(properties);
i++;
}
for (int a= 0; a<=i; a++){
System.out.println("nameArrays.get(a) -"+nameArrays.get(a));
sb.append(nameArrays.get(a));
}
paragraph.add(sb.toString());
document.add(paragraph);
document.close();
}
textService.getAnswer() this - ArrayList<String>
Could you please advise how to separate the text in order each new sentence will be starting from new row?
Now I see like this:

You forgot the newline character \n and your code seems a bit overcomplicated.
Try this:
StringBuffer sb = new StringBuffer();
for (String property : textService.getAnswer()) {
sb.append(property);
sb.append('\n');
}

What about:
nameArrays.add(properties+"\n");

You might be able to fix that by simply appending "\n" to the strings that you collecting in your list; but I think: that very much depends on the PDF library you are using.
You see, "newlines" or "paragraphs" are to a certain degree about formatting. It seems like a conceptual problem to add that "formatting" information to the data that you are processing.
Meaning: you might want to check if your library allows you to provide strings - and then have the library do the formatting for you!
In other words: instead of giving strings with newlines; you should check if you can keep using strings without newlines, but if there is way to have the PDF library add line breaks were appropriate.
Side note on code quality: you are using raw types:
ArrayList nameArrays = new ArrayList();
should better be
ArrayList<String> names = new ArrayList<>();
[ I also changed the name - there is no point in putting the type of a collection into the variable name! ]

This method is for save values in array list into a pdf document. In the mfilePath variable "/" in here you can give folder name. As a example "/example/".
and also for mFileName variable you can use name. I give the date and time that document will created. don't give static name other vice your values are overriding in same pdf.
private void savePDF()
{
com.itextpdf.text.Document mDoc = new com.itextpdf.text.Document();
String mFileName = new SimpleDateFormat("YYYY-MM-DD-HH-MM-SS", Locale.getDefault()).format(System.currentTimeMillis());
String mFilePath = Environment.getExternalStorageDirectory() + "/" + mFileName + ".pdf";
try
{
PdfWriter.getInstance(mDoc, new FileOutputStream(mFilePath));
mDoc.open();
for(int d = 0; d < g; d++)
{
String mtext = answers.get(d);
mDoc.add(new Paragraph(mtext));
}
mDoc.close();
}
catch (Exception e)
{
}
}

Get CSV file header using apache commons

I have been looking for the past 2 hours for a solution to my problem in vain. I'am trying to read a CSV File using Apache commons ,I am able to read the whole file but my problem is how to extract only the header of the CSV in an array?

I looked everywhere and even the solution above didn't work.
For anyone else with this issue, this does.
Iterable<CSVRecord> records;
Reader in = new FileReader(fileLocation);
records = CSVFormat.EXCEL.withHeader().withSkipHeaderRecord(false).parse(in);
Set<String> headers = records.iterator().next().toMap().keySet();
Note that your use of .next() has consumed one row of the CSV.

By default, first record read by CSVParser will always be a header record, e.g. in the below example:
CSVFormat csvFileFormat = CSVFormat.DEFAULT.withHeader(FILE_HEADER_MAPPING);
FileReader fileReader = new FileReader("file");
CSVParser csvFileParser = new CSVParser(fileReader, csvFileFormat);
List csvRecords = csvFileParser.getRecords();
csvRecords.get(0) will return the header record.

BufferedReader br = new BufferedReader(new FileReader(filename));
CSVParser parser = CSVParser.parse(br, CSVFormat.EXCEL.withFirstRecordAsHeader());
List<String> headers = parser.getHeaderNames();
This worked for me. The last line is what you need, extracts the headers found by the parser into a List of Strings.

Since Apache Commons CSV v1.9.0, the withSkipHeaderRecord() & the withFirstRecordAsHeader() methods are deprecated. A builder interface is provided. Use it thusly:
CSVFormat.DEFAULT.builder()
.setHeader()
.setSkipHeaderRecord(true)
.build();

In Kotlin:
val reader = File(path).bufferedReader()
val records = CSVFormat.DEFAULT.withFirstRecordAsHeader()
.withIgnoreHeaderCase()
.withTrim()
.parse(reader)
println(records.headerNames)

The code below works for me:
import java.io.FileReader;
import org.apache.commons.csv.*;
public static String[] headersInCSVFile (String csvFilePath) throws IOException {
//reading file
CSVFormat csvFileFormat = CSVFormat.DEFAULT;
FileReader fileReader = new FileReader(csvFilePath);
CSVParser csvFileParser = new CSVParser(fileReader, csvFileFormat);
List csvRecords = csvFileParser.getRecords();
//Obtaining first record and splitting that into an array using delimiters and removing unnecessary text
String[] headers = csvRecords.get(0).toString().split("[,'=\\]\\[]+");
String[] result = new String[headers.length - 6];
for (int i = 6; i < headers.length; i++) {
//.replaceAll("\\s", "") removes spaces
result[i - 6] = headers[i].replaceAll("\\s", "");
}
return result;
}

Csv: search for String and replace with another string

I have a .csv file that contains:
scenario, custom, master_data
1, ${CUSTOM}, A_1
I have a string:
a, b, c
and I want to replace 'custom' with 'a, b, c'. How can I do that and save to the existing .csv file?

Probably the easiest way is to read in one file and output to another file as you go, modifying it on a per-line basis
You could try something with tokenizers, this may not be completely correct for your output/input, but you can adapt it to your CSV file formatting
BufferedReader reader = new BufferedReader(new FileReader("input.csv"));
BufferedWriter writer = new BufferedWriter(new FileWriter("output.csv"));
String custom = "custom";
String replace = "a, b, c";
for(String line = reader.readLine(); line != null; line = reader.readLine())
{
String output = "";
StringTokenizer tokenizer = new StringTokenizer(line, ",");
for(String token = tokenizer.nextToken(); tokenizer.hasMoreTokens(); token = tokenizer.nextToken())
if(token.equals(custom)
output = "," + replace;
else
output = "," + token;
}
readInventory.close();
If this is for a one off thing, it also has the benefit of not having to research regular expressions (which are quite powerful and useful, good to know, but maybe for a later date?)

Have a look at Can you recommend a Java library for reading (and possibly writing) CSV files?
And once the values have been read, search for strings / value that start with ${ and end with }. Use Java Regular Expressions like \$\{(\w)\}. Then use some map for looking up the found key, and the related value. Java Properties would be a good candidate.
Then write a new csv file.

Since your replacement string is quite unique you can do it quickly without complicated parsing by just reading your file into a buffer, and then converting that buffer into a string. Replace all occurrences of the text you wish to replace with your target text. Then convert the string to a buffer and write that back to the file...
Pattern.quote is required because your string is a regular expression. If you don't quote it you may run into unexpected results.
Also it's generally not smart to overwrite your source file. Best is to create a new file then delete the old and rename the new to the old. Any error halfway will then not delete all your data.
final Path yourPath = Paths.get("Your path");
byte[] buff = Files.readAllBytes(yourPath);
String s = new String(buff, Charset.defaultCharset());
s = s.replaceAll(Pattern.quote("${CUSTOM}"), "a, b, c");
Files.write(yourPath, s.getBytes());

How do I write an array to .csv in Java?

I'm trying to write a piece of code in Java that generates an array of data, and I would like to write that data to a CSV file in one single column. However, I'm struggling with getting the correct output. My program generates the population in the array
double[] wasp = new double[1000];
which is populated by one of several functions, for instance:
for (int i = 0; i < wasp.length; i++) {
double mu = -10 + Math.random()*20;
double sigma = 0 + Math.random()*10;
wasp[i] = nextGaussian(mu, sigma);
description = "Normal";
Param1 = Double.toString(mu);
Param2 = Double.toString(sigma);
}
and I use the following code to try to write the array to CSV:
FileWriter writer = new FileWriter("C:\\Users\\Havok\\Google Drive\\Skripsie\\R\\JavaOut.csv");
for (int j = 0; j < wasp.length; j++) {
writer.append((char) wasp[j]);
writer.append(",");
}
writer.toString();
writer.flush();
writer.close();
However, when I open the CSV file, it looks "corrupt", as if the characters weren't encoded right or something. The data also fills up much more than one column in the file.
The output I expect is a CSV file that contains a single column of real values; for instance,
1.467354
0.812738
3.595733
and so on. However, what I'm getting is a column full of something like the following:
,,,,,,￶,,,,,,,￯,ï¿¿,,￾,,,,ï¿¿,,, ,,ï¿·,,￲,￲,,ï¿·,,,,,,ï¿·,,￸,￵,,,,,,￶,,,ï¿°,￸,,ï¿»,,￾,, ,,ï¿¿,,￾,,￯,,,,￵,,ï¿»,,￬,,ï¿·,￸,,,,ï¿
What am I doing wrong? I've looked at the tutorials on Java's home site and tried to adapt other similar solutions on StackOverflow, but it seems like I'm missing something crucial.

Simply convert your double to string using String.valueOf(double d) method.
FileWriter writer = new FileWriter("C:\\Users\\Havok\\Google Drive\\Skripsie\\R\\JavaOut.csv");
for (int j = 0; j < wasp.length; j++) {
writer.append(String.valueOf(wasp[j]));
writer.append("\n");
}
writer.close();
Alternatively you can use String.format() to format your double as you wanted.

In CSV format each set of data is delimited by a new line (\n) and each column is delimited by a comma. Therefore your code should look like this if you want a single column of data.
for (int j = 0; j < wasp.length; j++) {
writer.append((char) wasp[j]);
writer.append("\n");
}

Parsing A Text File, So That Every Line Is Stored As An Array Value

Basically, I want to parse, line by line, a Text file so that every line is in it's own array value.
E.g.
Hi There,
My Name's Aiden,
Not Really.
Array[0] = "Hi There"
Array[1] = "My Name's Aiden"
Array[2] = "Not Really"
But all the examples I have read already just confuse me and lead me to get frustrated. Maybe it's the way I approach it.
I don't know how to go about it, a point in the right direction would be most satisfying.

My suggestion is to use List<String> instead of String[] as arrays have fixed size, and that size is unknown before reading. Afterward one could make an array out of it, but to no real purpose.
For reading one has to know the encoding of the file.
Path path = Paths.get("C:/Users/Me/list.txt");
//Charset encoding = StandardCharsets.UTF_8;
Charset encoding = Charset.defaultCharset();
List<String> lines = Files.readAllLines(path, encoding);
for (String line : lines) {
...
}
for (int i = 0; i < lines.size(); ++i) {
String line = lines.get(i);
lines.set(i, "-- " + line;
}