EmailUtils.java
/*
* 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.
*/
package org.apache.commons.mail2.core;
import java.nio.charset.StandardCharsets;
import java.util.BitSet;
import java.util.Collection;
import java.util.Locale;
import java.util.Map;
import java.util.Random;
/**
* Utility methods used by commons-email.
* <p>
* These methods are copied from other commons components (commons-lang) to avoid creating a dependency for such a small component.
* </p>
* <p>
* This is a package scoped class, and should not be used directly by users.
* </p>
*
* @since 2.0.0
*/
public final class EmailUtils {
/**
* Random object used by random method. This has to be not local to the random method so as to not return the same value in the same millisecond.
*/
private static final Random RANDOM = new Random();
/**
* Radix used in encoding.
*/
private static final int RADIX = 16;
/**
* The escape character used for the URL encoding scheme.
*/
private static final char ESCAPE_CHAR = '%';
/**
* BitSet of RFC 2392 safe URL characters.
*/
private static final BitSet SAFE_URL = new BitSet(256);
// Static initializer for safe_uri
static {
// alpha characters
for (int i = 'a'; i <= 'z'; i++) {
SAFE_URL.set(i);
}
for (int i = 'A'; i <= 'Z'; i++) {
SAFE_URL.set(i);
}
// numeric characters
for (int i = '0'; i <= '9'; i++) {
SAFE_URL.set(i);
}
// safe chars
SAFE_URL.set('-');
SAFE_URL.set('_');
SAFE_URL.set('.');
SAFE_URL.set('*');
SAFE_URL.set('+');
SAFE_URL.set('$');
SAFE_URL.set('!');
SAFE_URL.set('\'');
SAFE_URL.set('(');
SAFE_URL.set(')');
SAFE_URL.set(',');
SAFE_URL.set('@');
}
/**
* Encodes an input string according to RFC 2392. Unsafe characters are escaped.
*
* @param input the input string to be URL encoded
* @return a URL encoded string
* @see <a href="https://tools.ietf.org/html/rfc2392">RFC 2392</a>
*/
public static String encodeUrl(final String input) {
if (input == null) {
return null;
}
final StringBuilder builder = new StringBuilder();
for (final byte c : input.getBytes(StandardCharsets.US_ASCII)) {
final int b = c & 0xff;
if (SAFE_URL.get(b)) {
builder.append((char) b);
} else {
builder.append(ESCAPE_CHAR);
final char hex1 = Character.toUpperCase(Character.forDigit(b >> 4 & 0xF, RADIX));
final char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, RADIX));
builder.append(hex1);
builder.append(hex2);
}
}
return builder.toString();
}
public static boolean isEmpty(final Collection<?> collection) {
return collection == null || collection.isEmpty();
}
public static boolean isEmpty(final Map<?, ?> map) {
return map == null || map.isEmpty();
}
public static boolean isEmpty(final Object[] array) {
return array == null || array.length == 0;
}
/**
* Checks if a String is empty ("") or null.
* <p>
* Copied from Commons Lang 2.1, svn 240418
* </p>
*
* @param str the String to check, may be null
* @return {@code true} if the String is empty or null
*/
public static boolean isEmpty(final String str) {
return str == null || str.isEmpty();
}
/**
* Checks if a String is not empty ("") and not null.
* <p>
* Copied from Commons Lang 2.1, svn 240418
* </p>
*
* @param str the String to check, may be null
* @return {@code true} if the String is not empty and not null
*/
public static boolean isNotEmpty(final String str) {
return str != null && !str.isEmpty();
}
/**
* Creates a random string based on a variety of options, using supplied source of randomness.
* <p>
* If start and end are both {@code 0}, start and end are set to {@code ' '} and {@code 'z'}, the ASCII printable characters, will be used, unless letters
* and numbers are both {@code false}, in which case, start and end are set to {@code 0} and {@code Integer.MAX_VALUE}.
* </p>
* <p>
* If set is not {@code null}, characters between start and end are chosen.
* </p>
* <p>
* This method accepts a user-supplied {@link Random} instance to use as a source of randomness. By seeding a single {@link Random} instance with a fixed
* seed and using it for each call, the same random sequence of strings can be generated repeatedly and predictably.
* </p>
* <p>
* Copied from Commons Lang 2.1, svn 201930
* </p>
*
* @param count the length of random string to create
* @param start the position in set of chars to start at
* @param end the position in set of chars to end before
* @param letters only allow letters?
* @param numbers only allow numbers?
* @param chars the set of chars to choose randoms from. If {@code null}, then it will use the set of all chars.
* @param random a source of randomness.
* @return the random string
* @throws IllegalArgumentException if {@code count} < 0.
*/
private static String random(int count, int start, int end, final boolean letters, final boolean numbers, final char[] chars, final Random random) {
if (count == 0) {
return "";
}
if (count < 0) {
throw new IllegalArgumentException("Requested random string length " + count + " is less than 0.");
}
if (start == 0 && end == 0) {
end = 'z' + 1;
start = ' ';
if (!letters && !numbers) {
start = 0;
end = Integer.MAX_VALUE;
}
}
final StringBuilder buffer = new StringBuilder();
final int gap = end - start;
while (count-- != 0) {
char ch;
if (chars == null) {
ch = (char) (random.nextInt(gap) + start);
} else {
ch = chars[random.nextInt(gap) + start];
}
if (letters && numbers && Character.isLetterOrDigit(ch) || letters && Character.isLetter(ch) || numbers && Character.isDigit(ch)
|| !letters && !numbers) {
buffer.append(ch);
} else {
count++;
}
}
return buffer.toString();
}
/**
* Creates a random string whose length is the number of characters specified.
* <p>
* Characters will be chosen from the set of alphabetic characters.
* </p>
* <p>
* Copied from Commons Lang 2.1, svn 201930
* </p>
*
* @param count the length of random string to create
* @return the random string
*/
public static String randomAlphabetic(final int count) {
return random(count, 0, 0, true, false, null, RANDOM);
}
/**
* Replaces end-of-line characters with spaces.
*
* @param input the input string to be scanned.
* @return a clean string
*/
public static String replaceEndOfLineCharactersWithSpaces(final String input) {
return input == null ? null : input.replace('\n', ' ').replace('\r', ' ');
}
public static String toLower(final String value) {
return value.toLowerCase(Locale.ROOT);
}
/**
* Constructs a new {@code EmailException} with no detail message.
*/
private EmailUtils() {
}
}