OSBuddy Exchange Price Lookup (Java 8)

[liverare]

Simple and native:

		int twistedBowId = 20997;
		String webAddress = null;
		String webContents = null;
		Map<String, String> jsonData = null;
		
		try {
			
			webAddress = "https://api.rsbuddy.com/grandExchange?a=guidePrice&i=" + twistedBowId;
			
			webContents = downloadWebpage(webAddress);
			
			jsonData = parseJsonKeyValuePairs(webContents);
			
			logger.debug(jsonData);
			
		} catch (IOException e) {
			logger.error("Failed to load price for: " + twistedBowId, e);
		}

Which outputs:

Quote

{buyingQuantity=3, buying=1090772410, overall=1090859846, selling=1090991000, sellingQuantity=2}

All that's missing is the parsing and possibly even a wrapper class. But the content's there.

The other functions (downloadWebpage & parseJsonKey:

	/**
	 * Download all contents from a URL
	 * 
	 * @param address
	 *            - Web site address
	 * @return Contents
	 * @throws IOException
	 *             Error input/output
	 */
	public static String downloadWebpage(String address) throws IOException {
		
		String result = "";
		String nextLine = null;
		
		try (
				InputStream inputStream = new URL(address).openStream();
				InputStreamReader inputStreamReader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
				BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
			) {
			
			while ((nextLine = bufferedReader.readLine()) != null) {
				
				result += nextLine;
			}
		}
		
		return result;
	}
	
	/**
	 * Simple JSON parser to extract key & value pairs.
	 * 
	 * Note: values must be numbers.
	 * 
	 * @param input
	 *            - JSON input
	 * @return Mapped contents
	 */
	public static Map<String, String> parseJsonKeyValuePairs(String input) {
		
		final Map<String, String> result = new HashMap<>();
		final Pattern pattern = Pattern.compile(".*?\"(.*?)\":(\\d+)", Pattern.CASE_INSENSITIVE | Pattern.DOTALL);		
		final Matcher matcher = pattern.matcher(input);
		
		while (matcher.find()) {
			
			result.put(matcher.group(1), matcher.group(2));
		}
		
		return result;
	}

I wrote my own JSON parser, but it's very simple and will only work where the values are numeric. I'm staying away from any libraries that aren't packaged with Java.

Also, don't suppress errors. If the errors are thrown at a point in the code where it can't be logged out, just keep throwing it on up the stack until it reaches a point where it can. Errors are useful; if you suppress them, then you're going to have a bad time.

Edited June 21, 2017 by liverare

[Viston]

Thanks

[Phaibooty]

Lit. Ty

[rallostar]

Thank you, was looking for this.