com.gihub.gkutiel.Fbi Maven / Gradle / Ivy

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Java API for Facebook apps

There is a newer version: 12-RELEASE

package com.gihub.gkutiel;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;

import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;

public class Fbi {
	private static final Gson gson = new Gson();
	final Map params = new HashMap<>();

	final String path;

	public Fbi(final String path) {
		this.path = path;
	}

	public Fbi accessToken(final String accessToken) {
		return param("access_token", accessToken);
	}

	public String get() throws IOException {
		return method("GET").fetch();
	}

	public  T getAs(final Class type) throws IOException {
		final String res = get();
		try {
			return gson.fromJson(res, type);
		} catch (final JsonSyntaxException e) {
			throw new RuntimeException("failed to parse\n" + res + "\nas " + type, e);
		}
	}

	public Fbi param(final String key, final String val) {
		params.put(key, val);
		return this;
	}

	private String buildQuery() {
		if (params.isEmpty()) return "";
		final StringBuilder query = new StringBuilder("?");

		for (final Entry param : params.entrySet())
			query.append(encode(param.getKey()) + "=" + encode(param.getValue()) + "&");

		query.deleteCharAt(query.length() - 1);

		return query.toString();
	}

	private String encode(final String str) {
		try {
			return URLEncoder.encode(str, "utf-8");
		} catch (final UnsupportedEncodingException e) {
			throw new RuntimeException(e);
		}
	}

	String buildUrl() {
		final StringBuilder url = new StringBuilder("https://graph.facebook.com/");
		url.append(path);
		url.append(buildQuery());
		return url.toString();
	}

	String fetch() throws IOException {
		try (final Scanner s = new Scanner(new URL(buildUrl()).openStream());) {
			return s.useDelimiter("\\A").next();
		}
	}

	Fbi method(final String method) {
		return param("method", method);
	}
}