Read Assets file as string

I would like to read the content of a file located in the Assets as a String. For example, a text document located in src/main/assets/

Original Question
I found that this question is mostly used as a 'FAQ' for reading an assets file, therefore I summarized the question above. Below is my original question

I'm trying to read a assets file as string. I have a file in my assets folder: data.opml, and want to read it as a string.

Some things I tried:

 AssetFileDescriptor descriptor = getAssets().openFd("data.opml");
 FileReader reader = new FileReader(descriptor.getFileDescriptor());

And also:

 InputStream input = getAssets().open("data.opml");
 Reader reader = new InputStreamReader(input, "UTF-8");

But without success, so a full example would be appreciated.

getAssets().open() will return an InputStream. Read from that using standard Java I/O:

Java:

StringBuilder sb = new StringBuilder();
InputStream is = getAssets().open("book/contents.json");
BufferedReader br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8 ));
String str;
while ((str = br.readLine()) != null) {
    sb.append(str);
}
br.close();

Kotlin:

val str = assets.open("book/contents.json").bufferedReader().use { it.readText() }

There is a little bug CommonsWare's code - newline characters are discarded and not added to the string. Here is some fixed code ready for copy+paste:

private String loadAssetTextAsString(Context context, String name) {
		BufferedReader in = null;
		try {
			StringBuilder buf = new StringBuilder();
			InputStream is = context.getAssets().open(name);
			in = new BufferedReader(new InputStreamReader(is));
			
		    String str;
		    boolean isFirst = true;
		    while ( (str = in.readLine()) != null ) {
		    	if (isFirst)
		    		isFirst = false;
		    	else
		    		buf.append('\n');
		    	buf.append(str);
		    }
		    return buf.toString();
		} catch (IOException e) {
			Log.e(TAG, "Error opening asset " + name);
		} finally {
			if (in != null) {
				try {
					in.close();
				} catch (IOException e) {
					Log.e(TAG, "Error closing asset " + name);
				}
			}
		}
		
		return null;
	}
	

You can also do it, without using loops. It's pretty simple

AssetManager assetManager = getAssets();
InputStream input;
String text = "";

	try {
		input = assetManager.open("test.txt");

		int size = input.available();
		byte[] buffer = new byte[size];
		input.read(buffer);
		input.close();

		// byte buffer into a string
		text = new String(buffer);

	} catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}

	Log.v("TAG", "Text File: " + text);

hi this is in my opinion the cleanest approach:

  public static String loadTextFromAssets(Context context, String assetsPath, Charset charset) throws IOException {
        InputStream is = context.getResources().getAssets().open(assetsPath);
        byte[] buffer = new byte[1024];
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        for (int length = is.read(buffer); length != -1; length = is.read(buffer)) {
            baos.write(buffer, 0, length);
        }
        is.close();
        baos.close();
        return charset == null ? new String(baos.toByteArray()) : new String(baos.toByteArray(), charset);
    }

because readers could get trouble with line breaks.