org.apache.empire.commons.StringUtils Maven / Gradle / Ivy
/*
* 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.empire.commons;
/**
* This class contains common functions for comparing and converting values of type String.
*
*/
public class StringUtils
{
private StringUtils()
{
// Static Function only
// No instance may be created
}
/**
* Converts a value to a string.
* If the value is null then the default value is returned.
*
* @param value the value to convert
* @param defValue default value which to return if value is null
* @return returns a String representation of the value or null if value is null
*/
public static String toString(Object value, String defValue)
{
return ((value!=null) ? value.toString() : defValue);
}
/**
* Converts a value to a string.
* If the value is null then null will be returned.
*
* @param value the value to convert
* @return returns a String representation of the value or null if value is null
*/
public static String toString(Object value)
{
return toString(value, null);
}
/**
* Converts an array of objects to a string.
*
* @param array array of objects
* @param defValue default value which to return if array is null
* @return returns a String representation of the array or the defaultValue if array is null
*/
public static String toString(Object[] array, String defValue)
{
String s = arrayToString(array, "/");
return (s!=null ? s : defValue);
}
/**
* Converts an array of objects to a string.
*
* @param array array of objects
* @return returns a String representation of the array or null if the array is null
*/
public static String toString(Object[] array)
{
return toString(array, null);
}
/**
* Converts a value to a string.
* if the value is null an empty string is returned.
*
* @param value the value to convert
* @return returns a String representation of the Object or an empty stringif o is null
*/
public static String valueOf(Object value)
{
return toString(value, "null");
}
/**
* Converts an objects to a string.
*
* @param array array of objects
* @return returns a String representation of the array or an empty String if the array is null
*/
public static String valueOf(Object[] array)
{
return toString(array, "null");
}
/**
* Returns the preferred String if it is not empty
* ot the alternative String otherwise.
*
* @param preferred the preferred String
* @param alternative the alternative String if the preferred String is not valid
* @return the preferred String if it is not empty ot the alternative String otherwise
*/
public static String coalesce(String preferred, String alternative)
{
return isValid(preferred) ? preferred : alternative;
}
/**
* Returns null if the value supplied is null or an empty String.
*
* @param value the value to check
* @return null if the value supplied is null or an empty String or the value as a string otherwise
*/
public static String nullIfEmpty(Object value)
{
if (value==null)
return null;
String strval = value.toString();
return ((strval.length()==0) ? null : strval);
}
/**
* Converts an array of objects to a string.
*
* @param array array of objects
* @param separator the separator to put between the object strings
* @return returns a String
*/
public static String arrayToString(Object[] array, String separator)
{
if (array == null || array.length < 1)
return null; // Empty
if (array.length > 1)
{ // multi Column Key
StringBuilder buf = new StringBuilder();
for (int i = 0; i < array.length; i++)
{
if (i>0 && separator!=null)
buf.append(separator);
buf.append(array[i]);
}
return buf.toString();
}
// Only one member
return String.valueOf(array[0]);
}
/**
* Checks if a string is empty
*
* @param s the String to check
*
* @return true if s is empty or null
*/
public static boolean isEmpty(String s)
{
return s == null || s.trim().length() == 0;
}
/**
* Checks if a string is not null or empty
*
* @param s the string to validate
*
* @return true if valid
*
* @deprecated this has been renamed to isNotEmpty
*/
@Deprecated
public static boolean isValid(String s)
{
return s != null && s.trim().length() > 0;
}
/**
* Checks if a string is not null or empty
*
* @param s the string to validate
*
* @return true if valid
*/
public static boolean isNotEmpty(String s)
{
return s != null && s.trim().length() > 0;
}
/**
* Compares two Strings with each other - either with or without character case. Both arguments may be null.
* @param s1 the first String
* @param s2 the second String
* @param ignoreCase whether to ignore the character casing or not
* @return true if the two strings supplied are equal
*/
public static boolean compareEqual(String s1, String s2, boolean ignoreCase)
{
if (s1==null || s2==null)
return (s1==s2);
// Compare
return (ignoreCase) ? s1.equalsIgnoreCase(s2) : s1.equals(s2);
}
/**
* Validates a given string. If the string is empty then null is returned.
* Otherwise the trimmed string is returned.
*
* @param s the string to validate
* @return the string or null if s was empty.
*/
public static String validate(String s)
{
if (s==null)
return null;
s = s.trim();
if (s.length()==0)
return null;
return s;
}
/**
* Replaces all occurrences of find in source by replace.
*
* @param source the original String.
* @param find the String to be replaced
* @param replace the replacement string
*
* @return a new string with all occurrences of find in source replaced by replace
*/
public static String replace(String source, String find, String replace)
{
// Check params
if (source == null || find == null || find.length()==0)
return source;
// Find the character
int index = source.indexOf(find);
if (index < 0)
return source;
if (replace==null)
replace="";
// replace and find again
int len = find.length();
return source.substring(0,index)
+ replace
+ replace(source.substring(index+len), find, replace);
}
/**
* Returns a String with all occurrences of from within orig replaced with to.
* If orig contains no occurrences of from, or if from is equal to
* to,orig itself is returned rather than a copy being made. If orig is null,
* null is returned.
*
* @param s the original String.
* @param find the String to be replaced
* @param replace the replacement string
*
* @return a new string with all occurrences of find in source replaced by replace
*/
public static String replaceAll(String s, String find, String replace)
{
if (s == null)
return null;
if (replace == null)
replace = "";
if (find == null || "".equals(find) || find.equals(replace))
{ // Nothing to find
return s;
}
int start = s.indexOf(find);
if (start < 0)
{ // Nothing to replace
return s;
}
// Rebuild string
StringBuilder b = new StringBuilder(s.length());
char[] origChars = s.toCharArray();
int findLength = find.length();
int copyFrom = 0;
while (start>= 0)
{ // append part
b.append(origChars, copyFrom, start - copyFrom);
if (replace.length()>0)
b.append(replace);
copyFrom = start + findLength;
start = s.indexOf(find, copyFrom);
}
// append the rest
if (origChars.length > copyFrom)
b.append(origChars, copyFrom, origChars.length - copyFrom);
// done
return b.toString();
}
/**
* Removes all occurrences of remove from s
* @param s the source string
* @param remove the string to remove
* @return the result string
*/
public static String remove(String s, String remove)
{
return replaceAll(s, remove, null);
}
/**
* Removes all occurrences of c from s
* @param s the source string
* @param c the character to remove
* @return the result string
*/
public static String remove(String s, char c)
{
return replaceAll(s, String.valueOf(c), null);
}
/**
* removes all blanks from s
* @param s the source string
* @return the result string
*/
public static String removeBlanks(String s)
{
return remove(s, " ");
}
/**
* returns true if the character c is between the characters beg and end
* @param c the source character
* @param beg the lower end character
* @param end the higher end character
* @return true if the c is between beg and end, or false otherwise
*/
public static boolean isCharBetween(char c, char beg, char end)
{
return (c>=beg && c<=end);
}
/**
* returns true if the character c is a number digit ('0'-'9')
* @param c the source character
* @return true if the c is between 0 and 9
*/
public static boolean isNumber(char c)
{
return (c>='0' && c<='9');
}
/**
* returns true if the string s is a number (contains only the characters 0 to 9)
* @param s the source string
* @return true if s contains only the characters 0 to 9
*/
public static boolean isNumber(String s)
{ if (isEmpty(s))
return false;
// check all chars
for (int i=0; i0)
return false;
if (!isNumeric(c, decimal))
return false;
}
return true;
}
/**
* returns true if the character c is an upper case character ('A'-'Z')
* @param c the character
* @return true if c is an upper case character
*/
public static boolean isUpper(char c)
{
return (c>='A' && c<='Z') || (c>='À' && c<='Ý');
}
/**
* returns true if the first count characters of s are all upper case (or other non-case sensitive characters)
* @param s the source string
* @return true if the first count characters of s are all upper case
*/
public static boolean isUpper(String s, int count)
{ if (isEmpty(s))
return false;
if (count>s.length())
count=s.length();
for (int i=0; i='a' && c<='z') || (c>='ß' && c<='ÿ');
}
/**
* returns true if the first count characters of s are all lower case (or other non-case sensitive characters)
* @param s the source string
* @return true if the first count characters of s are all lower case
*/
public static boolean isLower(String s, int count)
{ if (isEmpty(s))
return false;
if (count>s.length())
count=s.length();
for (int i=0; i © 2015 - 2025 Weber Informatics LLC | Privacy Policy