How to return my string value with whitespace

Question

How can I modify my main class so that I can receive values without losing the whitespace?

Here is a portion of my main class:

StringBuilder sb = new StringBuilder();
Scanner s = new Scanner(new FileReader(new File("C:/User/waithaka/Documents//duka.json")));
while (s.hasNext()) {
    sb.append(s.next());
}
s.close();

GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson = gsonBuilder.create();

String jstring = sb.toString();
Result results = gson.fromJson(jstring, Result.class);
List<data> dat = response.getData();
for (data data : dat) {
    System.out.println("The item is " + data.getItem());
}

The last line prints the values without whitespace. For example, a value with the string "Black and yellow" will be changed to "Blackandyellow".

Answer 1

If you look at Scanner.java class you can see white space treated as new line characters.

public Scanner(InputStream source) {
        this(new InputStreamReader(source), WHITESPACE_PATTERN);
    }

You need to set line separator as

s.useDelimiter(System.getProperty("line.separator"));

I was able to replicate and fix the problem, below is the code -

JSON

{
name:"Stack-overflow",
url:"http://www.stack-overflow   .com"
}

And here's the class

public class GsonTest {

    public static void main(String[] args) throws FileNotFoundException {
        StringBuilder sb = new StringBuilder();

        Scanner s = new Scanner(new FileReader(new File(
                "/Users/chatar/Documents/dev/projects/stack-overflow/stack-overflow/bin/C:/User/waithaka/Documents/duka.json")));

        s.useDelimiter(System.getProperty("line.separator"));
        while (s.hasNext()) {
            String nxt = s.next();
            sb.append(nxt);
        }
        s.close();

        GsonBuilder gsonBuilder = new GsonBuilder();
        Gson gson = gsonBuilder.create();

        String jstring = sb.toString();
        Result results = gson.fromJson(jstring, Result.class);

        System.out.println("The item is " + results);
    }
}

Answer 2

I think that your problem comes from using Scanner, since it may be trimming white spaces. As you are already using, some Google libraries (Gson), I would also use Google's guava, its Files class has a toString() method that will read a whole file to a String:

Files.toString()