Add to file instead of overwriting

Question

I have written a program that scraped source code twice, and created A CSV with specific information from the retrieved data. My issue is, when I go to save the second bit of data, instead of adding to the created CSV, it overwrites it with the new information. I have referred to this link, but it is using a different class. My code is currently:

  public static void scrapeWebsite() throws IOException {


    final WebClient webClient = new WebClient();
    final HtmlPage page = webClient.getPage(s);
    originalHtml = page.getWebResponse().getContentAsString();
    obtainInformation();
    originalHtml = "";
    final HtmlForm form = page.getForms().get(0);
    final HtmlSubmitInput button = form.getInputByValue(">");
    final HtmlPage page2 = button.click();
    try {
      synchronized (page2) {
        page2.wait(1000);
      }
    }
    catch(InterruptedException e)
    {
      System.out.println("error");
    }
    originalHtml = originalHtml + page2.refresh().getWebResponse().getContentAsString();
    obtainInformation();
  }

  public static void obtainInformation() throws IOException {

     PrintWriter docketFile = new PrintWriter(new FileWriter("tester3.csv", true));

// creates the csv file. (name must be changed, override deletes file) originalHtml = originalHtml.replace('"','*'); int i = 0;

    //While loop runs through all the data in the source code. There is (14) entries per page.
    while(i<14) {
      String plaintiffAtty = "PlaintiffAtty_"+i+"*>"; //creates the search string for the plaintiffatty
      Pattern plaintiffPattern = Pattern.compile("(?<="+Pattern.quote(plaintiffAtty)+").*?(?=</span>)");//creates the pattern for the atty
      Matcher plaintiffMatcher = plaintiffPattern.matcher(originalHtml); // looks for a match for the atty

      while (plaintiffMatcher.find()) {
        docketFile.write(plaintiffMatcher.group().toString()+", "); //writes the found atty to the file
      }
      i++;
    }
    docketFile.close(); //closes the file 
  } 
}

I believe the change will have to be made in the second method.

score 3 · Accepted Answer · answered Oct 24 '13 at 16:25

Your PrintWriter should reference a FileWriter constructed with the append constructor boolean set to true.

e.g

new PrintWriter(new FileWriter("myfile.csv", true));

Note the Javadoc for FileWriter re. your encoding specification:

Convenience class for writing character files. The constructors of this class assume that the default character encoding and the default byte-buffer size are acceptable. To specify these values yourself, construct an OutputStreamWriter on a FileOutputStream.

score 2 · Answer 2 · edited May 23 '17 at 11:50

2

It looks like you're trying to append to a file, but not opening your PrintWriter in append mode.

Refer to PrintWriter append method not appending

edited May 23 '17 at 11:50

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answered Oct 24 '13 at 16:25

AndyG

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Add to file instead of overwriting

2 Answers2