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.mail;
import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.BitSet;
import java.util.Random;
import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import org.apache.commons.mail.util.MimeMessageUtils;
/**
* 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 1.0
*/
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();
/**
* The default charset used for URL encoding.
*/
private static final String US_ASCII = "US-ASCII";
/**
* 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('@');
}
/**
* Constructs a new <code>EmailException</code> with no detail message.
*/
private EmailUtils()
{
super();
}
/**
* Checks if a String is empty ("") or null.
*
* @param str the String to check, may be null
*
* @return <code>true</code> if the String is empty or null
*
* @since Commons Lang v2.1, svn 240418
*/
static boolean isEmpty(final String str)
{
return (str == null) || (str.length() == 0);
}
/**
* Checks if a String is not empty ("") and not null.
*
* @param str the String to check, may be null
*
* @return <code>true</code> if the String is not empty and not null
*
* @since Commons Lang v2.1, svn 240418
*/
static boolean isNotEmpty(final String str)
{
return (str != null) && (str.length() > 0);
}
/**
* Validate an argument, throwing <code>IllegalArgumentException</code>
* if the argument is <code>null</code>.
*
* @param object the object to check is not <code>null</code>
* @param message the exception message you would like to see if the object is <code>null</code>
*
* @throws IllegalArgumentException if the object is <code>null</code>
*
* @since Commons Lang v2.1, svn 201930
*/
static void notNull(final Object object, final String message)
{
if (object == null)
{
throw new IllegalArgumentException(message);
}
}
/**
* Creates a random string whose length is the number of characters specified.
*
* <p>
* Characters will be chosen from the set of alphabetic characters.
* </p>
*
* @param count the length of random string to create
*
* @return the random string
*
* @since Commons Lang v2.1, svn 201930
*/
static String randomAlphabetic(final int count)
{
return random(count, 0, 0, true, false, null, RANDOM);
}
/**
* Creates a random string based on a variety of options, using supplied source of randomness.
*
* <p>
* If start and end are both <code>0</code>, start and end are set to <code>' '</code> and <code>'z'</code>,
* the ASCII printable characters, will be used, unless letters and numbers are both <code>false</code>,
* in which case, start and end are set to <code>0</code> and <code>Integer.MAX_VALUE</code>.
* </p>
*
* <p>
* If set is not <code>null</code>, 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>
*
* @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</code>,
* then it will use the set of all chars.
* @param random a source of randomness.
*
* @return the random string
*
* @throws IllegalArgumentException if <code>count</code> < 0.
*
* @since Commons Lang v2.1, svn 201930
*/
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 "";
}
else 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 StringBuffer buffer = new StringBuffer();
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();
}
/**
* Replaces end-of-line characters with spaces.
*
* @param input the input string to be scanned.
* @return a clean string
*/
static String replaceEndOfLineCharactersWithSpaces(final String input)
{
return input == null ? null : input.replace('\n', ' ').replace('\r', ' ');
}
/**
* 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
* @throws UnsupportedEncodingException if "US-ASCII" charset is not available
* @see <a href="http://tools.ietf.org/html/rfc2392">RFC 2392</a>
*/
static String encodeUrl(final String input) throws UnsupportedEncodingException
{
if (input == null)
{
return null;
}
final StringBuilder builder = new StringBuilder();
for (final byte c : input.getBytes(US_ASCII))
{
int b = c;
if (b < 0)
{
b = 256 + b;
}
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();
}
/**
* Convenience method to write a MimeMessage into a file.
*
* @param resultFile the file containing the MimeMessgae
* @param mimeMessage the MimeMessage to write
* @throws IOException writing the MimeMessage failed
* @throws MessagingException writing the MimeMessage failed
*/
static void writeMimeMessage(final File resultFile, final MimeMessage mimeMessage)
throws IOException, MessagingException
{
MimeMessageUtils.writeMimeMessage(mimeMessage, resultFile);
}
}