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Java Local Development Environments Advanced Tooling Finishing TreeStory

Posted by Unsubscribed User
Unsubscribed User
5,239 Points

NullPointerException in Matcher ?

Hey

I can't see where the problem in my code is?

I guess the Matcher is allright, but i pass in some weird stuff maybe .. or what ?

com/teamtreehouse/Main.java 
package com.teamtreehouse;

import java.util.Arrays;
import java.util.List;

public class Main {

    public static void main(String[] args) {

        Prompter prompter = new Prompter();
        String story = prompter.promptForStory();
        Template tmpl = new Template(story);
        prompter.run(tmpl);



    }
}
com/teamtreehouse/Prompter.java 
package com.teamtreehouse;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;


public class Prompter {
    private BufferedReader mReader;
    private Set<String> mCensoredWords;

    public Prompter() {
        mReader = new BufferedReader(new InputStreamReader(System.in));
        loadCensoredWords();
    }

    private void loadCensoredWords() {
        mCensoredWords = new HashSet<String>();
        Path file = Paths.get("resources", "censored_words.txt");
        List<String> words = null;
        try {
            words = Files.readAllLines(file);
        } catch (IOException e) {
            System.out.println("Couldn't load censored words");
            e.printStackTrace();
        }
        mCensoredWords.addAll(words);
    }

    public void run(Template tmpl) {
        List<String> results = null;
        try {
            results = promptForWords(tmpl);
        } catch (IOException e) {
            System.out.println("There was a problem prompting for words");
            e.printStackTrace();
            System.exit(0);
        }


        String finishedStory = tmpl.render(results);
        System.out.printf("%n Your Treestory:%n%n%s",finishedStory);
    }

    /**
     * Prompts user for each of the blanks
     *
     * @param tmpl The compiled template
     * @return
     * @throws IOException
     */
    public List<String> promptForWords(Template tmpl) throws IOException {
        List<String> words = new ArrayList<String>();
        for (String phrase : tmpl.getPlaceHolders()) {
            String word = promptForWord(phrase);
            words.add(word);
        }
        return words;
    }


    /**
     * Prompts the user for the answer to the fill in the blank.  Value is guaranteed to be not in the censored words list.
     *
     * @param phrase The word that the user should be prompted.  eg: adjective, proper noun, name
     * @return What the user responded
     */
    public String promptForWord(String phrase) throws IOException {

        System.out.printf("Please enter a %s:  ", phrase);
        String word = mReader.readLine().toLowerCase();

        while(mCensoredWords.contains(word)) {
            System.out.printf("Sorry %s is censored. Please try again:  ", word);
            word = mReader.readLine().toLowerCase();
        }

        return word;
    }

    public String promptForStory() {
        System.out.printf("Please Enter a story:  ");
        String story = null;
        try {
            mReader.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return story;
    }
}
pseudo-tests.md 
#  This is essentially what I am testing 
1.  The user is prompted for a new string template (the one with the double underscores in it).

  a. The prompter class has a new method that prompts for the story template, and that method is called.

2.  The user is then prompted for each word that has been double underscored.

   a. The answer is checked to see if it is contained in the censored words.
      User is continually prompted until they enter a valid word

3.  The user is presented with the completed story

1 Answer

Unsubscribed User
Unsubscribed User
5,239 Points

Taking the trash out apparently clears the mind ;)

Did not assign the result of readLine() to the story variable !

        public String promptForStory() {
        System.out.printf("Please Enter a story:  ");
        String story = null;
        try {
           story = mReader.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return story;
    }
Christopher Augg
Christopher Augg
21,223 Points
Christopher Augg
Christopher Augg
21,223 Points

Nice job finding that. I was just about to tell you that your promptForStory method was returning null. I am editing the forum post to display your code with syntax coloring. You can do this by using the ``` and the word java right after them.

Regards,

Chris

Unsubscribed User
Unsubscribed User
5,239 Points

So now I get a Bummer, that says "dork" gets through ?

I dont see how ?

    public String promptForWord(String phrase) throws IOException {

        System.out.printf("Please enter a %s:  ", phrase);
        String word = mReader.readLine().toLowerCase();

I'm prompting for the word, converting to lower case (so it matches the censored words in the txt), and then 'saving'/assigning it to the String word.

        while(mCensoredWords.contains(word)) {
            System.out.printf("Sorry %s is censored. Please try again:  ", word);
            word = mReader.readLine().toLowerCase();
        }

And as long as the word is in the list of censored words i keep prompting.

        return word;
    }

and only after that i return the word, of course.

Christopher Augg
Christopher Augg
21,223 Points
Christopher Augg
Christopher Augg
21,223 Points

Sorry Daniel, it looks like the test is being too specific and does not like the use of the printf in the while loop. I am testing it more but the following code passes:

public String promptForWord(String phrase) throws IOException {

        System.out.printf("Please enter a %s:  ", phrase);
        String word = mReader.readLine();

        while(mCensoredWords.contains(word)) {
            System.out.print("Sorry is censored. Please try again:  ");
            word = mReader.readLine();
        }

        return word;
    }
Unsubscribed User
Unsubscribed User
5,239 Points

Okay, Thanks - I got through now, and finally finished the Java Track :)

I also found that the toLowerCase(); I've used gives a Bummer, that says i didn't print treehousestory(3) or something like that.

  • That is any help to you.
Christopher Augg
Christopher Augg
21,223 Points
Christopher Augg
Christopher Augg
21,223 Points

Yes, seen that as well. Thanks. oh, and CONGRATULATIONS! Now its time to make some Android applications.