Best approach of reading data from text file and adding it to arraylist in android

Question

I am working on a project to get into android development, having some knowledge of java before I am thinking of reading data from a text file, which will be formatted like this;

Type: House
Image link: www.bit.ly/image1
Name: Black
Download Link: www.bit.ly/image1download 
----------
Type: Car
Image link: www.bit.ly/image2 
Name: yellow
Download Link: www.bit.ly/image2download 
----------
Type: Backyard
Image link: www.bit.ly/image3 
Name: Green
Download Link: www.bit.ly/image3download
----------
Type: Window
Image link: www.bit.ly/image4 
Name: Solid
Download Link: www.bit.ly/image4download 
----------
Type: Table
Image link: www.bit.ly/image5  
Name: Brown
Download Link: www.bit.ly/image5download 
----------

The data contains 4 pieces of information per set, Type, Image, Name and Download. I need a way of reading this and saving/writing it to a arraylist which I then can display in a listview that I will have on my app. (I am currently looking at tutorials on creating listview, if you know any useful tutorials please let me know)

Arraylist <String> data = new ArrayList<String>();
Data.add(“House”,” www.bit.ly/image1”,”black”,”www.bit.ly/image1download”);
Data.add(“Car”,” www.bit.ly/image2”,”yellow”,” www.bit.ly/image2download”);
……..
……..

In reality there will be a lot more data then just 5 sets , so I want to use for loop to loop through each data data and add it to the data arraylist.

I am not sure how I can approach this, any help is welcomed, I am really stuck. Please let me know if I have not explained my question properly.

EDITED:

Would this be the correct way of reading data from a textfile?

Scanner content = new Scanner(new File("Data.txt"));
ArrayList<String> data = new ArrayList<String>();
while (content.hasNext()){
    data.add(content.next());
}
content.close();

Or is this another way in android

Answer 1

Do this way define a setter getter class to hold and return values like this :

Data.class

public class Data {
String type,Image,Name,Link ;

public Data() {

}
public String getType() {
return type;
 }

 public void setType(String type) {
this.type = type;
  }

 public String getImage() {
return Image;
}

 public void setImage(String image) {
Image = image;
 }

 public String getName() {
return Name;
 }

 public void setName(String name) {
Name = name;
 }

 public String getLink() {
return Link;
  }

 public void setLink(String link) {
Link = link;
 }
 }

using for loop set data in a arraylist

Arraylist <Data> arrayListData = new ArrayList<Data>();
for(int i=0;i<arrayListData .size();i++){
 Data data=new Data();
 data.setType("");
 ...
 ...
 ...  
 arrayListData.add(data);
 }

and to fetch data from arraylist

String type= arrayListData.get(position).getType();

Updated :

read .txt file like this , I am assuming your text file is saved in sdcard of device :

    public void readfile() {
    StringBuilder text = new StringBuilder();
    File sdcard = Environment.getExternalStorageDirectory();
    ArrayList<Data> arrayList=new ArrayList<Data>();
    //Get the text file
    File file = new File(sdcard,"textfile.txt");

    //Read text from file


    try {
        BufferedReader br = new BufferedReader(new FileReader(file));
        String line;
        Data data=new Data();
        while ((line = br.readLine()) != null) {

            text.append(line);
            text.append('\n');
            if(line.contains(":")){
                int index=line.indexOf(":");
                String s=line.substring(index+1).trim();
                if(line.contains("Type")){
                    data.setType(s);
                }
                if(line.contains("Image")){
                    data.setImage(s);

                }
                if(line.contains("Name")){
                data.setName(s);

              }
             if(line.contains("Download")){
                data.setLink(s);
              }

            }
            if(line.contains("-")){
             arrayList.add(data);
             data=new Data();
            }
        }
        System.out.println(text);

        br.close();
    }
    catch (IOException e) {
        e.printStackTrace();

    }
    }

Answer 2

Before start go through this link for reading

How can I read a text file in Android?

Use PoJo Models for your needs,

Create a PoJo class like this

public class Film {

private String filmName;
private String mainStar;

public String getFilmName() {
    return filmName;
}
public void setFilmName(String filmName) {
    this.filmName = filmName;
}

public String getMainStar() {
    return mainStar;
}
public void setMainStar(String mainStar) {
    this.mainStar = mainStar;
}
}

Create ArrayList

private ArrayList<Film > filmArray=new ArrayList<Film>();

Store Each arraylist with instance of your PoJo class like this

for(int i=0;i<sizei++)
{
Film film=new Film();
film.setFilmName("your value");
film.setMainStar("your value");
filmArray.add(film);
}

and then access list of values in arraylist of PoJo class in filmArray list.

Simple and elegant solution.

Answer 3

Here is the parser

    public class FileParser {

    private static final String DATA_TERMINATION = "----------";

    private static final String TYPE="Type";
    private static final String IMAGE="Image link";
    private static final String NAME= "Name";
    private static final String DWNLD_LNK= "Download Link";

    public static void main(String[] args) {
        FileParser parser =  new FileParser();
        try {
            for(Data d:parser.parseDataFile(new File("F:\\data.txt"))){
                System.out.println(TYPE+":"+d.getType());
                System.out.println(IMAGE+":"+d.getImage());
                System.out.println(NAME+":"+d.getName());
                System.out.println(DWNLD_LNK+":"+d.getLink());
                System.out.println(DATA_TERMINATION);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public List<Data> parseDataFile(File input) throws Exception{
        List<Data> output =null;
        List<String> fileOp= null;
        try {

            validateInput(input);
            fileOp =  readFile(input);
            output = parseData(fileOp);



        } catch (Exception e) {
            throw e;
        }
        return output;


    }

    private List<Data> parseData(List<String> fileOp) {
        List<Data> output =null;

        output = new ArrayList<Data>();
        Data data;

        data = new Data();
        for(String line:fileOp){
            if(DATA_TERMINATION.equalsIgnoreCase(line)){
                output.add(data);
                data = new Data();
            }else{
                parseField(data,line);
            }
        }
        return output;
    }

    private void parseField(Data data, String line) {
        StringTokenizer tokenzr =  new StringTokenizer(line,":");
        if(tokenzr.countTokens() !=2){
            System.out.println("Cant parse line"+line);
        }else{

            switch (tokenzr.nextToken()) {
            case TYPE:
                data.setType(tokenzr.nextToken());
                break;
            case IMAGE:
                data.setImage(tokenzr.nextToken());
                break;
            case NAME:
                data.setName(tokenzr.nextToken());
                break;
            case DWNLD_LNK:
                data.setLink(tokenzr.nextToken());
                break;

            default:
                break;
            }
        }

    }

    private List<String> readFile(File input) throws Exception {

        BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(input)));
        String line = null;
        List<String> op = new ArrayList<String>();
        try {
            while((line = reader.readLine()) != null){
                op.add(line);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            throw e;
        }
        return op;
    }

    private void validateInput(File input) throws Exception {
        if(input == null){
            throw new Exception("Null input");      

        }else if(!input.exists() || !input.isFile() || !input.canRead()  ) {
            throw new Exception("File not readable");
        }

    }



}