gistfile1.txt

// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
 
// Will contain the raw JSON response as a string.
String forecastJsonStr = null;
 
try {
    // Construct the URL for the OpenWeatherMap query
    // Possible parameters are available at OWM's forecast API page, at
    // http://openweathermap.org/API#forecast
    URL url = new URL("http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7");
 
    // Create the request to OpenWeatherMap, and open the connection
    urlConnection = (HttpURLConnection) url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.connect();
 
    // Read the input stream into a String
    InputStream inputStream = urlConnection.getInputStream();
    StringBuffer buffer = new StringBuffer();
    if (inputStream == null) {
        // Nothing to do.
        forecastJsonStr = null;
    }
    reader = new BufferedReader(new InputStreamReader(inputStream));
 
    String line;
    while ((line = reader.readLine()) != null) {
        // Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
        // But it does make debugging a *lot* easier if you print out the completed
        // buffer for debugging.
        buffer.append(line + "\n");
    }
 
    if (buffer.length() == 0) {
        // Stream was empty.  No point in parsing.
        forecastJsonStr = null;
    }
    forecastJsonStr = buffer.toString();
} catch (IOException e) {
    Log.e("PlaceholderFragment", "Error ", e);
    // If the code didn't successfully get the weather data, there's no point in attempting
    // to parse it.
    forecastJsonStr = null;
} finally{
    if (urlConnection != null) {
        urlConnection.disconnect();
    }
    if (reader != null) {
        try {
            reader.close();
        } catch (final IOException e) {
            Log.e("PlaceholderFragment", "Error closing stream", e);
        }
    }
}

@korovyansk - it is just snipet, part of code, not even full method

This excerpt should have an "else" keyword, right?

    if (buffer.length() == 0) {
        // Stream was empty.  No point in parsing.
        forecastJsonStr = null;
    }
    forecastJsonStr = buffer.toString();

@marceloguedes buffer.toString() will return "" if nothing has been appended. And, we don't want forecastJsonStr to be null.

@briansudev Then why do we set it to null inside that "if" statement?

Also, this seems rather pointless:

if (inputStream == null) {
    // Nothing to do.
    forecastJsonStr = null;
}

forecastJsonStr is already null at that point (and can't be anything else) and we go on to simply using the input stream anyway, so why bother to do this check? It may be there as a placeholder to build on, but still pretty useless at this point.

Here's an updated version. https://gist.github.com/KamilLelonek/cec2a775a439ce2ebc4e

@KamilLelonek you've got a bug in your code trying to instantiate Httpconnection when it should be HttpURLConnection. That was unfortunate.

there are more bugs in his code, cause it can't compile..

@gier3k in case of .java it will be highlighted as java code, and will be much easy to read :)

Join to others.

1. The language of the code here is not text, it's Java. Enable code higlighting, please.
2. if (inputStream == null) {
   // Nothing to do.
   forecastJsonStr = null;
   }
   on line 23. It is useless, forecastJsonStr is null, if you mean return null here, it's better to write it.
3. The same on line 37, forecastJsonStr can't be not null. Why don't you write return, if you mean return?
   if (buffer.length() == 0) {
   // Stream was empty. No point in parsing.
   forecastJsonStr = null;
   }
4. I think, synchronized StringBuffer is useless here, we should use StringBuilder.
   @gier3k the language of snippet is Java, it's not plain text snippet.

In regards to StringBuffer vs StringBuilder, StringBuffer is a syncronized thread safe class however, since it's threaded suprisingly it runs slower than StringBuilder. So unless you are using threads on the data it's faster to use StringBuilder. In the end though both will work just the same as the other.

Why don't you change format .txt to .java for highlight syntax?

Has anybody a hint why the repeated

forecastJsonStr = null;

is for? I am new to Java, but these seem totally useless, because it has already that value.

It's protection. Yes, forecastJsonStr is supposed to be null at this point - there's nothing in the code (so far) that will make it not null. But you can get some truly weird and undetectable bugs by assuming that a string that should be null is null. It's a heck of a lot safer to explicitly set it null.
If you were writing for a Timex-Sinclair or a 2001 smartphone (2K-64K memory), it might be worth leaving it out to save a line or two of code. We've got the room, now, to write for safety - and the person who works on your code after you will be MUCH happier if you do.

why in the world do we live in, is there so much outdated code in tutorials? it takes a second to get an ambitious intern to make a video that is completely up to date. These tutorials suck

I did a network-snippet myself as this looked pretty bad. The only thing the code above does is fetching some json from a website. So why don't just use a external method that can be reused for it?`-

public String getPageSource(String pageUrl)
{
    StringBuffer buffer = new StringBuffer();

    try
    {
        URL url = new URL(pageUrl);
        InputStream is = url.openStream();
        int pointer = 0;
        while ((pointer = is.read()) != -1) 
        {
            buffer.append((char)ptr);
        }
    } catch (Exception e) {e.printStackTrace();}

    return buffer.toString();
}

Have fun with it :)

So it's safe to use StringBuilder instead of StringBuffer as threads are not in play here?

In the following code, the MyOpenWeatherMapApiKey you got from OWM should be wrapped in single quote and then double quote for the app to run (at least in my case)

buildTypes.each {
    it.buildConfigField 'String', 'OPEN_WEATHER_MAP_API_KEY', ' "MyOpenWeatherMapApiKey" '
}

@biniama Thanks for your help.
My environment: Mac, Android Studio 1.5

@biniama Thanks! You saved me the trouble.

This is my understanding of this code snippet,

Task
We have to send a HTTP request to an URL and GET some data.

Solving

• Create a new variable for the URL
  new URL(...)
• Use the URL to create and open HttpURLConnection
  openConnection()
• Now send a GET request
  setRequestMethod("GET")
• If we get response for our request
  inputStream != null
  buffer the data and store it as a String.
  new BufferedReader()
• And "finally" close the HttpURLConnection
  disconnect()

i still don't understand why ->

// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;

can someone tell me why can't I close that if I put them inside try block?

it.buildConfigField 'String', 'OPEN_WEATHER_MAP_API_KEY', ""xxxxxxxxxxxxxxxxxx""

@wahidnurhani because in that case these variables will be in the inner score of the try block and not visible in the finally block.

Guys, Please understand this is a code snippet

this is not a valid java file

Hence, why it's not in .java...Not to be rude but if you need it in .java you are more than capable.

agree with @randypfofl, this is just code snippet. you can change everything with your coding style.

I did not received any error on my end. I then tried running the URL and found invalid API Key as follows,

{"cod":401, "message": "Invalid API key. Please see http://openweathermap.org/faq#error401 for more info."}

Please help me on this.

I found the solution by myself... It is just because the Open Weather Map has updated their portal saying that they have made few things secure due to which you will have to generate registered API Key. I used mine and now its working fine!

But when I am trying to use the URL in the app the is still not showing any error. The App continues to work fine... Strange!

@VaibhavAWD well, it still crashes for me. Maybe you're adding it in the wrong location?

I wrote the network call using the Ion library.

Ion.with(this)
                    .load(baseURL.concat(api_key))
                    .asString()
                    .setCallback(new FutureCallback<String>() {
                        @Override
                        public void onCompleted(Exception e, String result) {
                            if(result != null) {
                                logResult(result);
                            }

                        }
                    });