Reading a txt file and outputing as a TextView in

问题:

I am trying to read a text file that is already saved in my directory and print it on the screen as a TextView. This is the code that I have so far. However, when I run the application, it creates a toast which says "Error Reading File". What am I doing wrong here?

public class sub extends Activity {

private TextView text;


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.text);
    //text = (TextView) findViewById(R.id.summtext);
    //File file = new File("inputNews.txt");        
    //StringBuilder text = new StringBuilder();
    try {
        InputStream in = openFileInput("inputNews.txt");

        if(in != null){
            InputStreamReader reader = new InputStreamReader(in);
            BufferedReader br = new BufferedReader(reader);
            StringBuilder text = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                text.append(line);
                text.append('\n');
            }   
            in.close();            

        }

    }
    catch (IOException e) {
        Toast.makeText(getApplicationContext(),"Error reading file!",Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }


    TextView output= (TextView) findViewById(R.id.summtext);
    output.setText((CharSequence) text);

}

}

回答1:

If you want to keep a .txt file in your Project, you must locate it in the assets folder.
Then you can access it with AssetManger .
Read this topic on how to create your assets folder, and then use this code:

public class subActivity extends Activity {

private TextView textView;
private StringBuilder text = new StringBuilder();

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.text);
    BufferedReader reader = null;

    try {
        reader = new BufferedReader(
            new InputStreamReader(getAssets().open("inputNews.txt")));

        // do reading, usually loop until end of file reading  
        String mLine;
        while ((mLine = reader.readLine()) != null) {
            text.append(mLine);
            text.append('\n');
        }
    } catch (IOException e) {
        Toast.makeText(getApplicationContext(),"Error reading file!",Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } finally {
        if (reader != null) {
        try {
            reader.close();
        } catch (IOException e) {
            //log the exception
        }
    }

    TextView output= (TextView) findViewById(R.id.summtext);
    output.setText((CharSequence) text);

 }
}

回答2:

As far as I know you cannot read file from so called development folder. But you can move the same file to assets folder in development folder and read from there. ie.

try {
BufferedReader reader = new BufferedReader(
    new InputStreamReader(getAssets().open("inputNews.txt")));

StringBuilder text = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
         text.append(line);
         text.append('\n');
}   
} catch (IOException e) {
    Toast.makeText(getApplicationContext(),"Error reading file!",Toast.LENGTH_LONG).show();
    e.printStackTrace();
}

I hope it helps

回答3:

You should store those files in assets or raw directory.

And after that you can get inputstream from those files by using ,

If using assets

AssetManager am = context.getAssets();
InputStream is = am.open("test.txt");

OR if you use raw directory then ,

InputStream is = getResources().openRawResource(R.raw.test);

回答4:

This is the Kotlin version of the answer from above:

var text = ""
var reader: BufferedReader? = null

try {
    reader = BufferedReader(InputStreamReader(assets.open("inputNews.txt")))
    text = reader.readLines().joinToString("\n")
} catch (e: IOException) {
    Toast.makeText(applicationContext, "Error reading license file!", Toast.LENGTH_SHORT).show()
    e.printStackTrace()
} finally {
    try {
        reader?.close()
    } catch (e: IOException) {
        //log the exception
        e.printStackTrace()
    }
    textView.text = text
}