Read text from a URL

Develop a java program that reads in strings from the following URL and stores them in a sorted list.

Problem Specification

Develop a java program that reads in strings from the following URL and stores them in a sorted list.

• http://dl.dropbox.com/u/18678304/2011/BSc2/words.txt

The user should then be able to enter a sub-string and the program should return a list of matching strings that contain the substring. All matching strings should be displayed, sorted and the search should be case insensitive.

Implementation Steps

• Create a class called WordList. An instance of the WordList class should have a list of all the words from the URL above(hint: use composition). The WordList class should implement this interface.

package algorithms;

import java.util.List;

public interface StringSearchInterface {

  public abstract List<String> getSubstringList(String subString);

  public abstract void addString(String s);

}

As you have not covered networking or exceptions in Java I’ve included a link to an example constructor for WordList(NOTE: it’s not complete!). However you should try to to figure out how to read from a URL yourself using the web (Try googling “read from url java”). Example constructor excerpt here:

  public WordList(String urlString) throws IOException {

    BufferedReader in = null;
    try {
      wordList = new ArrayList<String>();
      in = new BufferedReader(new InputStreamReader(new URL(urlString).openStream()));
      String inputLine;
      while ((inputLine = in.readLine()) != null)
        wordList.add(inputLine);
    }
    finally {
      if (in != null)
        in.close();
    }
  }

JUint Test

• The following JUnit test case will give you an indication of further implementation details and should be usable without modification. You can also include more rigorous test cases is you wish.

package algorithms;

import static org.junit.Assert.*;
import java.util.List;
import org.junit.Test;

public class WordListTest {

  private static final String url = "http://dl.dropbox.com/u/18678304/2011/BSc2/words.txt";

  @Test
  public void testAddString() throws Exception {
    StringSearchInterface wordList;
    String s = "I Love Javaaaaaa!";
    String searchString = "love";

    wordList = new WordList(url);

    wordList.addString(s);
    System.out.println(wordList.getSubstringList(searchString).size());
    // check that the search returned some results
    assertTrue(wordList.getSubstringList(s).size() == 1);

  }

  @Test
  public void testGetSubstringList() throws Exception {
    StringSearchInterface wordList;
    String s = "umb";

    wordList = new WordList(url);
    List<String> resultList = wordList.getSubstringList(s);

    // check that the search returned some result(i.e. there is a match
    // in the list)
    assertTrue(resultList.size() > 0);

  }

  @Test
  public void testWordList() throws Exception {
    StringSearchInterface wordList;

    wordList = new WordList(url);
    assertNotNull(wordList);
  }
}