CODEWITHSUNDEEP
javaandroidfileexception
mike
mike

Reputation: 1338

Reading from a file location contained in package

I have a .txt file which contains a list of stuff I want to store in an Array and use throughout my application. To achieve this I created the following class:

public class Sort {

ArrayList<String> sorted = new ArrayList<String>();

public Sort() throws IOException {
    Scanner scanner = new Scanner(new FileReader("/home/scibor/coding/src/com/myapp/readThis.txt"));
    while(scanner.hasNextLine()){
        sorted.add(scanner.nextLine());
    }
}
}

So I have a .txt file with a bunch of stuff in it, and then I create this class specifically for that case. Now when I want to access these things in the .txt file in an ArrayList in one of my other classes, I figure:

Sort sort = new Sort();
sort.sorted; //can use the arrayList like so

Instead I get a message that says UnhandledException: java.io.IOException

I've tried several variations of this using try/catch, BufferedReader with try/catch/finally and ultimately all of them have some sort of error pertaining to the Exceptions that are raised by reading in a file. What am I doing wrong here?

EDIT: As per one of the suggestions, I have tried a radically different approach as below:

public class Sort {

List<String> sorted;

public Sort(Context context){

    sorted = new ArrayList<String>();
    AssetManager assetManager = context.getAssets();
    try {
        InputStream read = assetManager.open("readThis.txt");
        BufferedReader reader = new BufferedReader(new InputStreamReader(read));
        while(reader.readLine() != null){
            sorted.add(reader.readLine());
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}
}

This seems to get me further, and is probably very close to the correct answer. When I create Sort mySortedObject = new Sort(this); there are no errors generated. When I finally access the ArrayList though, as follows:

for(String name: mySortedObject.sort){
    if(name.equals("Whatever"){
        //run this
            }
        }
    }

I get a NullPointerException on the line containing the if statement. So the object was successfully created...but not quite?

EDIT: The "readThis.txt" file is located in /assets

Upvotes: 0

Views: 51

Answers (1)

Simon Forsberg
Simon Forsberg

Reputation: 13351

I believe the file "/home/scibor/coding/src/com/myapp/readThis.txt" does not exist on your phone (and for a good reason). You will need to add your .txt as an asset to your project and load it using the AssetManager.open()-method

Edit:

In your edited code, your NullPointerException is caused by you calling .readLine() twice in each iteration.

Solution:

String line = null;
while(true){
     line = reader.readLine();
     if (line == null) break;
     sorted.add(line);
 }

Upvotes: 2

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