Question

private void readIncomingMessage() {
    try {
        StringBuilder builder = new StringBuilder();
        InputStream is = socket.getInputStream();
        int length = 1024;
        byte[] array = new byte[length];
        int n = 0;

        while ((n = is.read(array, n, 100)) != -1) {
            builder.append(new String(array));

            if (checkIfComplete(builder.toString())) {
                buildListItems(builder.toString(), null);
                builder = new StringBuilder();
            }
        }

    } catch (IOException e) {
        Log.e("TCPclient", "Something went wrong while reading the socket");
    }
}

Hi,

I want to read the stream per block of 100 bytes, convert those bytes into a string and than see if that strings fits certain conditions.

But when I debug I see that builder has a count of 3072.
And I see a string like (text, , , , , , , , , , text , , , , , , , , , text)
How can I just add the text to the stringbuilder?

thx 🙂

 private void readIncomingMessage() {
    try {
        StringBuilder builder = new StringBuilder();
        InputStream is = socket.getInputStream();
        int length = 100;
        byte[] array = new byte[length];
        int n = 0;

        while ((n = is.read(array, 0, length)) != -1) {
            builder.append(new String(array, 0, n));

            if (checkIfComplete(builder.toString())) {
                buildListItems(builder.toString(), null);
                builder = new StringBuilder();
            }
        }

    } catch (IOException e) {
        Log.e("TCPclient", "Something went wrong while reading the socket");
    }
}

this solution did the trick for me.
any drawbacks with this solution?

Answer 1

2 problems:

1. you need to use the 'n' value when converting the bytes to a String. Specifically, use this String constructor String(byte[] bytes, int offset, int length)
2. when converting bytes to strings on arbitrary boundaries, like you are doing, you have the potential to corrupt multi-byte characters. You’d be better off putting an InputStreamReader on top if the 'is' and reading characters from that.