Junit Test case for void method which creates a file

Question

I have Java program which fetches HTML from a website. It displays the content on console and then saves it to a file named web_content.txt. How do I write a test case for this?

My Program is:

public class UrlDown {
   public static void main(String[] args) throws Exception {
      UrlDown down = new UrlDown();
      File f = new File("web_content.txt");
      String loc = "http://www.google.com";
      down.saveUrlToFile(f, loc);

   }

   public void saveUrlToFile(File saveFile, String location) {
      URL url;
      try {
         url = new URL(location);
         BufferedReader in = new BufferedReader(new InputStreamReader(
               url.openStream()));
         BufferedWriter out = new BufferedWriter(new FileWriter(saveFile));

         char[] cbuf = new char[255];
         StringBuilder builder = new StringBuilder();
         while ((in.read(cbuf)) != -1) {
            out.write(cbuf);
            builder.append(cbuf);
         }
         String downloaded = builder.toString();
         System.out.println();
         System.out.println(downloaded);
         in.close();
         out.close();

      } catch (MalformedURLException e) {
         e.printStackTrace();
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

Whats thet question? There's nothing about Junit in the code you provided. — Tom, Apr 26 '12 at 14:39

score 1 · Answer 1 · answered Apr 26 '12 at 14:50

1

Don't reinvent the square wheel. Just use some lib.

For example FileUtils from apache-commons - http://commons.apache.org/io/apidocs/org/apache/commons/io/FileUtils.html#copyURLToFile(java.net.URL, java.io.File)

answered Apr 26 '12 at 14:50

Kiril Kirilov

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score 0 · Answer 2 · edited May 23 '17 at 12:12

0

If you are on Java 7, you can use the Files.copy() method to save the content of a InputStreamto a file.

To verify that this is working you can use the TemporaryFolder from jUnit to verify that you get the location correct, see https://stackoverflow.com/a/6185359/303598

edited May 23 '17 at 12:12

Community

1
1

answered Apr 26 '12 at 14:42

matsev

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score 0 · Answer 3 · answered Apr 26 '12 at 14:45

0

Have your unit test setup a mock http server (google will give you plenty of info). Pass in a url and check the file contains the expected content

answered Apr 26 '12 at 14:45

vickirk

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Junit Test case for void method which creates a file

3 Answers3