Question

I have this code, which contains a BufferedReader and reads the HTML data from a website. However, every page from the site which I’m loading contains like 600 lines of HTML, so it takes a long time for it to read the data every time. I want to the code more efficient by not reading lines which start (for instance) with the letters/word ‘on’. Can this be done? This is my code:

public String getInternetData(String s) throws Exception { 
    BufferedReader in = null;  
    try{ 
        HttpClient client = new DefaultHttpClient(); 
        URI website = new URI(s);
        HttpGet request = new HttpGet(); 
        request.setURI(website); 
        HttpResponse response = client.execute(request);
        in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
        StringBuffer sb = new StringBuffer(""); 
        String l = ""; 
        String nl = System.getProperty("line.seperator");
        while(((l = in.readLine()) != null)){
            sb.append(l+nl); 
            }
        in.close();
        return sb.toString(); 
    }finally{
        try { 
            if(in != null) { 
                in.close(); 
            }
        }catch(Exception e){ 
            e.printStackTrace(); 
        }
}

}

This code is fully working, and returns a string with the HTML of the entire webpage. Any way of filtering out lines starting with “on”, without reading the entire line first?

Answer 1

To know if a line starts with “on” you must first determine that there has been a newline character. To do this you must read the whole line. In shorter terms – no – it is not possible to read certain lines from a stream without reading the whole stream.

If you knew the position of the lines you could use the .skip() method – but the implementation of this might simply read past the bytes not wanted.