Java tutorial
package com.fsck.k9.helper; import android.content.Context; import android.database.Cursor; import android.graphics.Bitmap; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.os.Handler; import android.os.Looper; import android.provider.ContactsContract; import android.provider.MediaStore; import android.text.Editable; import android.text.TextUtils; import timber.log.Timber; import android.widget.EditText; import android.widget.TextView; import com.fsck.k9.ui.ContactBadge; import com.fsck.k9.mail.Address; import org.apache.commons.io.FileUtils; import org.apache.commons.io.IOUtils; import org.apache.james.mime4j.util.MimeUtil; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Utility { // \u00A0 (non-breaking space) happens to be used by French MUA // Note: no longer using the ^ beginning character combined with (...)+ // repetition matching as we might want to strip ML tags. Ex: // Re: [foo] Re: RE : [foo] blah blah blah private static final Pattern RESPONSE_PATTERN = Pattern .compile("((Re|Fw|Fwd|Aw|R\\u00E9f\\.)(\\[\\d+\\])?[\\u00A0 ]?: *)+", Pattern.CASE_INSENSITIVE); /** * Mailing-list tag pattern to match strings like "[foobar] " */ private static final Pattern TAG_PATTERN = Pattern.compile("\\[[-_a-z0-9]+\\] ", Pattern.CASE_INSENSITIVE); private static Handler sMainThreadHandler; /** * The path of the temporary directory that is used to store resized image attachments. * The directory is cleaned as soon as message is sent. */ private static final String RESIZED_ATTACHMENTS_TEMPORARY_DIRECTORY = "/tempAttachments/"; public static boolean arrayContains(Object[] a, Object o) { for (Object element : a) { if (element.equals(o)) { return true; } } return false; } public static boolean isAnyMimeType(String o, String... a) { for (String element : a) { if (MimeUtil.isSameMimeType(element, o)) { return true; } } return false; } public static boolean arrayContainsAny(Object[] a, Object... o) { for (Object element : a) { if (arrayContains(o, element)) { return true; } } return false; } /** * Combines the given array of Objects into a single String using * each Object's toString() method and the separator character * between each part. * * @param parts * @param separator * @return new String */ public static String combine(Object[] parts, char separator) { if (parts == null) { return null; } return TextUtils.join(String.valueOf(separator), parts); } /** * Combines the given Objects into a single String using * each Object's toString() method and the separator character * between each part. * * @param parts * @param separator * @return new String */ public static String combine(Iterable<?> parts, char separator) { if (parts == null) { return null; } return TextUtils.join(String.valueOf(separator), parts); } public static boolean requiredFieldValid(TextView view) { return view.getText() != null && view.getText().length() > 0; } public static boolean requiredFieldValid(Editable s) { return s != null && requiredFieldValid(s.toString()); } public static boolean requiredFieldValid(String s) { return s != null && s.length() > 0; } public static boolean domainFieldValid(EditText view) { return view != null && view.getText() != null && domainFieldValid(view.getText().toString()); } public static boolean domainFieldValid(String s) { return s.matches( "^([a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?\\.)*[a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?$") && s.length() <= 253 || s.matches( "^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$"); } /* * TODO disabled this method globally. It is used in all the settings screens but I just * noticed that an unrelated icon was dimmed. Android must share drawables internally. */ public static void setCompoundDrawablesAlpha(TextView view, int alpha) { // Drawable[] drawables = view.getCompoundDrawables(); // for (Drawable drawable : drawables) { // if (drawable != null) { // drawable.setAlpha(alpha); // } // } } /** * <p>Wraps a multiline string of text, identifying words by <code>' '</code>.</p> * * <p>New lines will be separated by the system property line separator. * Very long words, such as URLs will <i>not</i> be wrapped.</p> * * <p>Leading spaces on a new line are stripped. * Trailing spaces are not stripped.</p> * * <pre> * WordUtils.wrap(null, *) = null * WordUtils.wrap("", *) = "" * </pre> * * Adapted from the Apache Commons Lang library. * http://svn.apache.org/viewvc/commons/proper/lang * /trunk/src/main/java/org/apache/commons/lang3/text/WordUtils.java * SVN Revision 925967, Mon Mar 22 06:16:49 2010 UTC * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. * * @param str the String to be word wrapped, may be null * @param wrapLength the column to wrap the words at, less than 1 is treated as 1 * @return a line with newlines inserted, <code>null</code> if null input */ private static final String NEWLINE_REGEX = "(?:\\r?\\n)"; public static String wrap(String str, int wrapLength) { StringBuilder result = new StringBuilder(); for (String piece : str.split(NEWLINE_REGEX)) { result.append(wrap(piece, wrapLength, null, false)); result.append("\r\n"); } return result.toString(); } /** * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p> * * <p>Leading spaces on a new line are stripped. * Trailing spaces are not stripped.</p> * * <pre> * WordUtils.wrap(null, *, *, *) = null * WordUtils.wrap("", *, *, *) = "" * </pre> * * This is from the Apache Commons Lang library. * http://svn.apache.org/viewvc/commons/proper/lang * /trunk/src/main/java/org/apache/commons/lang3/text/WordUtils.java * SVN Revision 925967, Mon Mar 22 06:16:49 2010 UTC * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. * * @param str the String to be word wrapped, may be null * @param wrapLength the column to wrap the words at, less than 1 is treated as 1 * @param newLineStr the string to insert for a new line, * <code>null</code> uses the system property line separator * @param wrapLongWords true if long words (such as URLs) should be wrapped * @return a line with newlines inserted, <code>null</code> if null input */ public static String wrap(String str, int wrapLength, String newLineStr, boolean wrapLongWords) { if (str == null) { return null; } if (newLineStr == null) { newLineStr = "\r\n"; } if (wrapLength < 1) { wrapLength = 1; } int inputLineLength = str.length(); int offset = 0; StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32); while ((inputLineLength - offset) > wrapLength) { if (str.charAt(offset) == ' ') { offset++; continue; } int spaceToWrapAt = str.lastIndexOf(' ', wrapLength + offset); if (spaceToWrapAt >= offset) { // normal case wrappedLine.append(str.substring(offset, spaceToWrapAt)); wrappedLine.append(newLineStr); offset = spaceToWrapAt + 1; } else { // really long word or URL if (wrapLongWords) { // wrap really long word one line at a time wrappedLine.append(str.substring(offset, wrapLength + offset)); wrappedLine.append(newLineStr); offset += wrapLength; } else { // do not wrap really long word, just extend beyond limit spaceToWrapAt = str.indexOf(' ', wrapLength + offset); if (spaceToWrapAt >= 0) { wrappedLine.append(str.substring(offset, spaceToWrapAt)); wrappedLine.append(newLineStr); offset = spaceToWrapAt + 1; } else { wrappedLine.append(str.substring(offset)); offset = inputLineLength; } } } } // Whatever is left in line is short enough to just pass through wrappedLine.append(str.substring(offset)); return wrappedLine.toString(); } /** * Extract the 'original' subject value, by ignoring leading * response/forward marker and '[XX]' formatted tags (as many mailing-list * softwares do). * * <p> * Result is also trimmed. * </p> * * @param subject * Never <code>null</code>. * @return Never <code>null</code>. */ public static String stripSubject(final String subject) { int lastPrefix = 0; final Matcher tagMatcher = TAG_PATTERN.matcher(subject); String tag = null; // whether tag stripping logic should be active boolean tagPresent = false; // whether the last action stripped a tag boolean tagStripped = false; if (tagMatcher.find(0)) { tagPresent = true; if (tagMatcher.start() == 0) { // found at beginning of subject, considering it an actual tag tag = tagMatcher.group(); // now need to find response marker after that tag lastPrefix = tagMatcher.end(); tagStripped = true; } } final Matcher matcher = RESPONSE_PATTERN.matcher(subject); // while: // - lastPrefix is within the bounds // - response marker found at lastPrefix position // (to make sure we don't catch response markers that are part of // the actual subject) while (lastPrefix < subject.length() - 1 && matcher.find(lastPrefix) && matcher.start() == lastPrefix && (!tagPresent || tag == null || subject.regionMatches(matcher.end(), tag, 0, tag.length()))) { lastPrefix = matcher.end(); if (tagPresent) { tagStripped = false; if (tag == null) { // attempt to find tag if (tagMatcher.start() == lastPrefix) { tag = tagMatcher.group(); lastPrefix += tag.length(); tagStripped = true; } } else if (lastPrefix < subject.length() - 1 && subject.startsWith(tag, lastPrefix)) { // Re: [foo] Re: [foo] blah blah blah // ^ ^ // ^ ^ // ^ new position // ^ // initial position lastPrefix += tag.length(); tagStripped = true; } } } // Null pointer check is to make the static analysis component of Eclipse happy. if (tagStripped && (tag != null)) { // restore the last tag lastPrefix -= tag.length(); } if (lastPrefix > -1 && lastPrefix < subject.length() - 1) { return subject.substring(lastPrefix).trim(); } else { return subject.trim(); } } public static String stripNewLines(String multiLineString) { return multiLineString.replaceAll("[\\r\\n]", ""); } private static final String IMG_SRC_REGEX = "(?is:<img[^>]+src\\s*=\\s*['\"]?([a-z]+)\\:)"; private static final Pattern IMG_PATTERN = Pattern.compile(IMG_SRC_REGEX); /** * Figure out if this part has images. * TODO: should only return true if we're an html part * @param message Content to evaluate * @return True if it has external images; false otherwise. */ public static boolean hasExternalImages(final String message) { Matcher imgMatches = IMG_PATTERN.matcher(message); while (imgMatches.find()) { String uriScheme = imgMatches.group(1); if (uriScheme.equals("http") || uriScheme.equals("https")) { Timber.d("External images found"); return true; } } Timber.d("No external images."); return false; } /** * Unconditionally close a Cursor. Equivalent to {@link Cursor#close()}, * if cursor is non-null. This is typically used in finally blocks. * * @param cursor cursor to close */ public static void closeQuietly(final Cursor cursor) { if (cursor != null) { cursor.close(); } } /** * Check to see if we have network connectivity. */ public static boolean hasConnectivity(final Context context) { final ConnectivityManager connectivityManager = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivityManager == null) { return false; } final NetworkInfo netInfo = connectivityManager.getActiveNetworkInfo(); if (netInfo != null && netInfo.getState() == NetworkInfo.State.CONNECTED) { return true; } else { return false; } } private static final Pattern MESSAGE_ID = Pattern.compile("<" + "(?:" + "[a-zA-Z0-9!#$%&'*+\\-/=?^_`{|}~]+" + "(?:\\.[a-zA-Z0-9!#$%&'*+\\-/=?^_`{|}~]+)*" + "|" + "\"(?:[^\\\\\"]|\\\\.)*\"" + ")" + "@" + "(?:" + "[a-zA-Z0-9!#$%&'*+\\-/=?^_`{|}~]+" + "(?:\\.[a-zA-Z0-9!#$%&'*+\\-/=?^_`{|}~]+)*" + "|" + "\\[(?:[^\\\\\\]]|\\\\.)*\\]" + ")" + ">"); public static List<String> extractMessageIds(final String text) { List<String> messageIds = new ArrayList<String>(); Matcher matcher = MESSAGE_ID.matcher(text); int start = 0; while (matcher.find(start)) { String messageId = text.substring(matcher.start(), matcher.end()); messageIds.add(messageId); start = matcher.end(); } return messageIds; } public static String extractMessageId(final String text) { Matcher matcher = MESSAGE_ID.matcher(text); if (matcher.find()) { return text.substring(matcher.start(), matcher.end()); } return null; } public static String getResizedImageFile(Context context, Uri uri, float multiplier) { File cacheDir = context.getCacheDir(); File tempAttachmentsDirectory = new File(cacheDir.getPath() + RESIZED_ATTACHMENTS_TEMPORARY_DIRECTORY); tempAttachmentsDirectory.mkdirs(); File tempFile = null; Bitmap bitmap = null; Bitmap resized = null; FileOutputStream out = null; try { tempFile = File.createTempFile("TempResizedAttachment", null, tempAttachmentsDirectory); bitmap = MediaStore.Images.Media.getBitmap(context.getContentResolver(), uri); resized = Bitmap.createScaledBitmap(bitmap, (int) (bitmap.getWidth() * multiplier), (int) (bitmap.getHeight() * multiplier), true); out = new FileOutputStream(tempFile); resized.compress(Bitmap.CompressFormat.PNG, 100, out); } catch (IOException e) { Timber.e(e, "Error while resizing image attachment"); return ""; } finally { IOUtils.closeQuietly(out); } return tempFile.getAbsolutePath(); } public static void clearTemporaryAttachmentsCache(Context context) { File cacheDir = context.getCacheDir(); File tempAttachmentsDirectory = new File(cacheDir.getPath() + RESIZED_ATTACHMENTS_TEMPORARY_DIRECTORY); if (tempAttachmentsDirectory.exists()) { try { FileUtils.cleanDirectory(tempAttachmentsDirectory); } catch (IOException e) { Timber.e(e, "Error occurred while cleaning temporary directory for resized attachments"); } } } public static boolean isImage(Context context, Uri uri) { return context.getContentResolver().getType(uri).contains("image"); } /** * @return a {@link Handler} tied to the main thread. */ public static Handler getMainThreadHandler() { if (sMainThreadHandler == null) { // No need to synchronize -- it's okay to create an extra Handler, which will be used // only once and then thrown away. sMainThreadHandler = new Handler(Looper.getMainLooper()); } return sMainThreadHandler; } /** * Assign the contact to the badge. * * On 4.3, we pass the address name as extra info so that if the contact doesn't exist * the name is auto-populated. * * @param contactBadge the badge to the set the contact for * @param address the address to look for a contact for. */ public static void setContactForBadge(ContactBadge contactBadge, Address address) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) { Bundle extraContactInfo = new Bundle(); extraContactInfo.putString(ContactsContract.Intents.Insert.NAME, address.getPersonal()); contactBadge.assignContactFromEmail(address.getAddress(), true, extraContactInfo); } else { contactBadge.assignContactFromEmail(address.getAddress(), true); } } }