/*
* 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 info.ineighborhood.cardme.util;
/**
* Copyright (c) 2004, Neighborhood Technologies
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Neighborhood Technologies nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/**
*
* @author George El-Haddad
* <br/>
* Aug 25, 2006
*
* <p>General utility methods to help dealing with Strings.</p>
*/
public final class StringUtil {
private static final char[] HEX_CHARS = {
'0', '1', '2' ,'3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f'
};
private StringUtil() {
}
/**
* <p>Counts how many times an instance of a specified character occurs in the
* target string.</p>
*
* @param target
* @param instance
* @return int
*/
public static int countInstanceOf(String target, char instance)
{
return countInstanceOf(target, String.valueOf(instance));
}
/**
* <p>Counts how many times an instance of a specified substring occurs in the
* target string.</p>
*
* @param target
* @param instance
* @return int
*/
public static int countInstanceOf(String target, String instance)
{
int fieldNum = 0;
int pos = 0;
int val = 0;
boolean stop = false;
while (!stop) {
val = target.indexOf(instance, pos);
if (val != -1) {
fieldNum++;
pos = val + 1;
}
else {
stop = true;
}
}
return fieldNum;
}
/**
* <p>Given an array of bytes, it will return the representation as a string of hex data.
* This is primarily useful when needing to display encrypted data as a readable string.</p>
*
* @param bytes
* - the bytes to convert to hex
* @return {@link String}
*/
public static String toHexString(byte[] bytes)
{
StringBuilder sb = new StringBuilder();
for(int i = 0; i < bytes.length; i++) {
byte b = bytes[i];
sb.append(new char[] {HEX_CHARS[(b >> 4) & 0x0f], HEX_CHARS[b & 0x0f]});
}
return sb.toString();
}
/**
* <p>Returns a formatted string in the java style exception format.</p>
*
* @param ex
* - the exception to format
* @return {@link String}
*/
public static String formatException(Throwable ex)
{
StringBuilder sb = new StringBuilder();
sb.append(ex.getMessage());
sb.append("\n");
StackTraceElement[] trace = ex.getStackTrace();
for(int i=0; i < trace.length; i++) {
sb.append("\t");
sb.append(trace[i]);
sb.append("\n");
}
return sb.toString();
}
/**
* <p>Given a String it will pad it to the specified length.</p>
*
* @param string
* - the string to pad
* @param length
* - the amount of characters to pad
* @param charToPad
* - the pad character to use
* @return {@link String}
* - the padded string
*/
public static String padStringWith(String string, int length, char charToPad)
{
if(string.length() == length) {
return string;
}
StringBuilder sb = new StringBuilder();
sb.append(string);
int len = sb.length();
for(int i=len; i < length; i++) {
sb.insert(0, charToPad);
}
return sb.toString();
}
}