Java tutorial
/* * Copyright (c) 2015 Ha Duy Trung * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.github.hidroh.materialistic.accounts; import android.content.Context; import android.net.Uri; import android.support.v4.util.Pair; import android.text.TextUtils; import android.widget.Toast; import java.io.IOException; import java.net.HttpURLConnection; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.inject.Inject; import io.github.hidroh.materialistic.AppUtils; import io.github.hidroh.materialistic.R; import okhttp3.Call; import okhttp3.FormBody; import okhttp3.HttpUrl; import okhttp3.Request; import okhttp3.Response; import rx.Observable; import rx.Scheduler; import rx.android.schedulers.AndroidSchedulers; public class UserServicesClient implements UserServices { private static final String BASE_WEB_URL = "https://news.ycombinator.com"; private static final String LOGIN_PATH = "login"; private static final String VOTE_PATH = "vote"; private static final String COMMENT_PATH = "comment"; private static final String SUBMIT_PATH = "submit"; private static final String ITEM_PATH = "item"; private static final String SUBMIT_POST_PATH = "r"; private static final String LOGIN_PARAM_ACCT = "acct"; private static final String LOGIN_PARAM_PW = "pw"; private static final String LOGIN_PARAM_CREATING = "creating"; private static final String LOGIN_PARAM_GOTO = "goto"; private static final String ITEM_PARAM_ID = "id"; private static final String VOTE_PARAM_ID = "id"; private static final String VOTE_PARAM_HOW = "how"; private static final String COMMENT_PARAM_PARENT = "parent"; private static final String COMMENT_PARAM_TEXT = "text"; private static final String SUBMIT_PARAM_TITLE = "title"; private static final String SUBMIT_PARAM_URL = "url"; private static final String SUBMIT_PARAM_TEXT = "text"; private static final String SUBMIT_PARAM_FNID = "fnid"; private static final String SUBMIT_PARAM_FNOP = "fnop"; private static final String VOTE_DIR_UP = "up"; private static final String DEFAULT_REDIRECT = "news"; private static final String CREATING_TRUE = "t"; private static final String DEFAULT_FNOP = "submit-page"; private static final String DEFAULT_SUBMIT_REDIRECT = "newest"; private static final String REGEX_INPUT = "<\\s*input[^>]*>"; private static final String REGEX_VALUE = "value[^\"]*\"([^\"]*)\""; private static final String HEADER_LOCATION = "location"; private static final String HEADER_COOKIE = "cookie"; private static final String HEADER_SET_COOKIE = "set-cookie"; private final Call.Factory mCallFactory; private final Scheduler mIoScheduler; @Inject public UserServicesClient(Call.Factory callFactory, Scheduler ioScheduler) { mCallFactory = callFactory; mIoScheduler = ioScheduler; } @Override public void login(String username, String password, boolean createAccount, Callback callback) { execute(postLogin(username, password, createAccount)) .map(response -> response.code() == HttpURLConnection.HTTP_MOVED_TEMP) .observeOn(AndroidSchedulers.mainThread()).subscribe(callback::onDone, callback::onError); } @Override public boolean voteUp(Context context, String itemId, Callback callback) { Pair<String, String> credentials = AppUtils.getCredentials(context); if (credentials == null) { return false; } Toast.makeText(context, R.string.sending, Toast.LENGTH_SHORT).show(); execute(postVote(credentials.first, credentials.second, itemId)) .map(response -> response.code() == HttpURLConnection.HTTP_MOVED_TEMP) .observeOn(AndroidSchedulers.mainThread()).subscribe(callback::onDone, callback::onError); return true; } @Override public void reply(Context context, String parentId, String text, Callback callback) { Pair<String, String> credentials = AppUtils.getCredentials(context); if (credentials == null) { callback.onDone(false); return; } execute(postReply(parentId, text, credentials.first, credentials.second)) .map(response -> response.code() == HttpURLConnection.HTTP_MOVED_TEMP) .observeOn(AndroidSchedulers.mainThread()).subscribe(callback::onDone, callback::onError); } @Override public void submit(Context context, String title, String content, boolean isUrl, Callback callback) { Pair<String, String> credentials = AppUtils.getCredentials(context); if (credentials == null) { callback.onDone(false); return; } /** * The flow: * POST /submit with acc, pw * if 302 to /login, considered failed * POST /r with fnid, fnop, title, url or text * if 302 to /newest, considered successful * if 302 to /x, considered error, maybe duplicate or invalid input * if 200 or anything else, considered error */ // fetch submit page with given credentials execute(postSubmitForm(credentials.first, credentials.second)).flatMap( response -> response.code() != HttpURLConnection.HTTP_MOVED_TEMP ? Observable.just(response) : Observable.error(new IOException())) .flatMap(response -> { try { return Observable.just( new String[] { response.header(HEADER_SET_COOKIE), response.body().string() }); } catch (IOException e) { return Observable.error(e); } finally { response.close(); } }).map(array -> { array[1] = getInputValue(array[1], SUBMIT_PARAM_FNID); return array; }) .flatMap(array -> !TextUtils.isEmpty(array[1]) ? Observable.just(array) : Observable.error(new IOException())) .flatMap(array -> execute(postSubmit(title, content, isUrl, array[0], array[1]))) .flatMap(response -> response.code() == HttpURLConnection.HTTP_MOVED_TEMP ? Observable.just(Uri.parse(response.header(HEADER_LOCATION))) : Observable.error(new IOException())) .flatMap(uri -> TextUtils.equals(uri.getPath(), DEFAULT_SUBMIT_REDIRECT) ? Observable.just(true) : Observable.error(buildException(uri))) .observeOn(AndroidSchedulers.mainThread()).subscribe(callback::onDone, callback::onError); } private Request postLogin(String username, String password, boolean createAccount) { FormBody.Builder formBuilder = new FormBody.Builder().add(LOGIN_PARAM_ACCT, username) .add(LOGIN_PARAM_PW, password).add(LOGIN_PARAM_GOTO, DEFAULT_REDIRECT); if (createAccount) { formBuilder.add(LOGIN_PARAM_CREATING, CREATING_TRUE); } return new Request.Builder() .url(HttpUrl.parse(BASE_WEB_URL).newBuilder().addPathSegment(LOGIN_PATH).build()) .post(formBuilder.build()).build(); } private Request postVote(String username, String password, String itemId) { return new Request.Builder().url(HttpUrl.parse(BASE_WEB_URL).newBuilder().addPathSegment(VOTE_PATH).build()) .post(new FormBody.Builder().add(LOGIN_PARAM_ACCT, username).add(LOGIN_PARAM_PW, password) .add(VOTE_PARAM_ID, itemId).add(VOTE_PARAM_HOW, VOTE_DIR_UP).build()) .build(); } private Request postReply(String parentId, String text, String username, String password) { return new Request.Builder() .url(HttpUrl.parse(BASE_WEB_URL).newBuilder().addPathSegment(COMMENT_PATH).build()) .post(new FormBody.Builder().add(LOGIN_PARAM_ACCT, username).add(LOGIN_PARAM_PW, password) .add(COMMENT_PARAM_PARENT, parentId).add(COMMENT_PARAM_TEXT, text).build()) .build(); } private Request postSubmitForm(String username, String password) { return new Request.Builder() .url(HttpUrl.parse(BASE_WEB_URL).newBuilder().addPathSegment(SUBMIT_PATH).build()) .post(new FormBody.Builder().add(LOGIN_PARAM_ACCT, username).add(LOGIN_PARAM_PW, password).build()) .build(); } private Request postSubmit(String title, String content, boolean isUrl, String cookie, String fnid) { Request.Builder builder = new Request.Builder() .url(HttpUrl.parse(BASE_WEB_URL).newBuilder().addPathSegment(SUBMIT_POST_PATH).build()) .post(new FormBody.Builder().add(SUBMIT_PARAM_FNID, fnid).add(SUBMIT_PARAM_FNOP, DEFAULT_FNOP) .add(SUBMIT_PARAM_TITLE, title).add(isUrl ? SUBMIT_PARAM_URL : SUBMIT_PARAM_TEXT, content) .build()); if (!TextUtils.isEmpty(cookie)) { builder.addHeader(HEADER_COOKIE, cookie); } return builder.build(); } private Observable<Response> execute(Request request) { return Observable.defer(() -> { try { return Observable.just(mCallFactory.newCall(request).execute()); } catch (IOException e) { return Observable.error(e); } }).subscribeOn(mIoScheduler); } private Throwable buildException(Uri uri) { switch (uri.getPath()) { case ITEM_PATH: UserServices.Exception exception = new UserServices.Exception(R.string.item_exist); String itemId = uri.getQueryParameter(ITEM_PARAM_ID); if (!TextUtils.isEmpty(itemId)) { exception.data = AppUtils.createItemUri(itemId); } return exception; default: return new IOException(); } } private String getInputValue(String html, String name) { // extract <input ... > Matcher matcherInput = Pattern.compile(REGEX_INPUT).matcher(html); while (matcherInput.find()) { String input = matcherInput.group(); if (input.contains(name)) { // extract value="..." Matcher matcher = Pattern.compile(REGEX_VALUE).matcher(input); return matcher.find() ? matcher.group(1) : null; // return first match if any } } return null; } }