io.fabric8.utils.Strings Maven / Gradle / Ivy
/**
* Copyright 2005-2016 Red Hat, Inc.
*
* Red Hat 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 io.fabric8.utils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
public class Strings {
/**
* Returns true if the given text is not null and not empty
*/
public static boolean notEmpty(String text) {
return text != null && text.length() > 0;
}
public static String nullIfEmpty(String value) {
if (value == null || value.length() == 0) {
return null;
} else {
return value;
}
}
public static String emptyIfNull(String value) {
if (value == null) {
return "";
} else {
return value;
}
}
public static String defaultIfEmpty(String value, String defaultValue) {
return notEmpty(value) ? value : defaultValue;
}
/**
* Returns the first string value which is not null and not blank
*/
public static String firstNonBlank(String... values) {
for (String value : values) {
if (notEmpty(value)) {
return value;
}
}
return null;
}
/**
* splits a string into a list of strings, ignoring the empty string
*/
public static List splitAsList(String text, String delimiter) {
List answer = new ArrayList();
if (text != null && text.length() > 0) {
answer.addAll(Arrays.asList(text.split(delimiter)));
}
return answer;
}
/**
* splits a string into a list of strings. Trims the results and ignores empty strings
*/
public static List splitAndTrimAsList(String text, String sep) {
ArrayList answer = new ArrayList();
if (text != null && text.length() > 0) {
for (String v : text.split(sep)) {
String trim = v.trim();
if (trim.length() > 0) {
answer.add(trim);
}
}
}
return answer;
}
/**
* joins a collection of objects together as a String using a separator
*/
public static String join(final Collection collection, final String separator) {
StringBuffer buffer = new StringBuffer();
boolean first = true;
Iterator iter = collection.iterator();
while (iter.hasNext()) {
Object next = iter.next();
if (first) {
first = false;
} else {
buffer.append(separator);
}
buffer.append(next);
}
return buffer.toString();
}
/**
* joins a collection of objects together as a String using a separator
*/
public static String join(final String separator, Object... objects) {
StringBuffer buffer = new StringBuffer();
boolean first = true;
for (Object object : objects) {
if (first) {
first = false;
} else {
buffer.append(separator);
}
buffer.append(object);
}
return buffer.toString();
}
/**
* joins a collection of objects together as a String using a separator, filtering out null values
*/
public static String joinNotNull(final String separator, Object... objects) {
StringBuffer buffer = new StringBuffer();
boolean first = true;
for (Object object : objects) {
if (object == null) continue;
if (first) {
first = false;
} else {
buffer.append(separator);
}
buffer.append(object);
}
return buffer.toString();
}
public static String toString(Object object) {
if (object == null) {
return "null";
} else if (object instanceof Object[]) {
return Arrays.asList((Object[]) object).toString();
} else {
return object.toString();
}
}
public static String unquote(String text) {
if (text != null && text.startsWith("\"") && text.endsWith("\"")) {
return text.substring(1, text.length() - 1);
} else {
return text;
}
}
/**
* This method is used to pad a line by max length with a delimiter.
* @param delimiter - String that will be used to concatenate to the end of line
* @param str - string input that will be changed and returned
* @param max - size of the maximum length of a string
* @return
*/
public static String rpad(String delimiter, String str, int max){
for(int i=1; i<= max; i++){
str = str.concat(delimiter);
}
return str;
}
/**
* When you have a line that has a maximum length and want to pad the remaining space with ' ' whitespace then
* this method is for you.
* @param delimiter - String that will be used to concatenate to the end of line
* @param str - string input that will be changed and returned
* @param max - size of the maximum length of a string
* @return
*/
public static String rpadByMaxSize(String delimiter, String str, int max){
int len= max- str.length();
for(int i=1; i<= len; i++){
str = str.concat(delimiter);
}
return str;
}
public static boolean isNullOrBlank(String value) {
return value == null || value.length() == 0 || value.trim().length() == 0;
}
public static boolean isNotBlank(String text) {
return !isNullOrBlank(text);
}
public static String stripPrefix(String value, String suffix) {
if (!value.startsWith(suffix)) {
return value;
} else {
return value.substring(suffix.length());
}
}
public static String stripSuffix(String value, String suffix) {
if (!value.endsWith(suffix)) {
return value;
} else {
return value.substring(0, value.length() - suffix.length());
}
}
public static List parseDelimitedString(String value, String delim) {
return parseDelimitedString(value, delim, true);
}
/**
* Parses delimited string and returns an array containing the tokens. This
* parser obeys quotes, so the delimiter character will be ignored if it is
* inside of a quote. This method assumes that the quote character is not
* included in the set of delimiter characters.
*
* @param value the delimited string to parse.
* @param delim the characters delimiting the tokens.
* @return a list of string or an empty list if there are none.
*/
public static List parseDelimitedString(String value, String delim, boolean trim) {
if (value == null) {
value = "";
}
List list = new ArrayList();
int CHAR = 1;
int DELIMITER = 2;
int STARTQUOTE = 4;
int ENDQUOTE = 8;
StringBuffer sb = new StringBuffer();
int expecting = (CHAR | DELIMITER | STARTQUOTE);
boolean isEscaped = false;
for (int i = 0; i < value.length(); i++) {
char c = value.charAt(i);
boolean isDelimiter = (delim.indexOf(c) >= 0);
if (!isEscaped && (c == '\\')) {
isEscaped = true;
continue;
}
if (isEscaped) {
sb.append(c);
} else if (isDelimiter && ((expecting & DELIMITER) > 0)) {
if (trim) {
list.add(sb.toString().trim());
} else {
list.add(sb.toString());
}
sb.delete(0, sb.length());
expecting = (CHAR | DELIMITER | STARTQUOTE);
} else if ((c == '"') && ((expecting & STARTQUOTE) > 0)) {
sb.append(c);
expecting = CHAR | ENDQUOTE;
} else if ((c == '"') && ((expecting & ENDQUOTE) > 0)) {
sb.append(c);
expecting = (CHAR | STARTQUOTE | DELIMITER);
} else if ((expecting & CHAR) > 0) {
sb.append(c);
} else {
throw new IllegalArgumentException("Invalid delimited string: " + value);
}
isEscaped = false;
}
if (sb.length() > 0) {
if (trim) {
list.add(sb.toString().trim());
} else {
list.add(sb.toString());
}
}
return list;
}
/**
* Converts the given text with the given separator into camelCase
*/
public static String convertToCamelCase(String text, String separator) {
StringBuffer buffer = new StringBuffer();
String[] words = text.split(separator);
boolean first = true;
for (String word : words) {
if (first) {
buffer.append(word);
first = false;
} else {
if (word.length() > 0) {
buffer.append(Character.toUpperCase(word.charAt(0)));
if (word.length() > 1) {
buffer.append(word.substring(1));
}
}
}
}
return buffer.toString();
}
/**
* Splits a CamelCase string using a space between them.
*/
public static String splitCamelCase(String text) {
return splitCamelCase(text, " ");
}
/**
* Splits a CamelCase string using a separator string between them.
*/
public static String splitCamelCase(String text, String separator) {
StringBuilder buffer = new StringBuilder();
char last = 'A';
for (char c: text.toCharArray()) {
if (Character.isLowerCase(last) && Character.isUpperCase(c)) {
buffer.append(separator);
}
buffer.append(c);
last = c;
}
return buffer.toString();
}
// String based functions
public static Function toLowerCaseFunction() {
return new Function() {
@Override
public String toString() {
return "toLowerCaseFunction()";
}
@Override
public String apply(String value) {
if (value != null) {
return value.toLowerCase();
}
return null;
}
};
}
public static Function toUpperCaseFunction() {
return new Function() {
@Override
public String toString() {
return "toUpperCaseFunction()";
}
@Override
public String apply(String value) {
if (value != null) {
return value.toUpperCase();
}
return null;
}
};
}
/**
* Converts a string to a valid environment variable by removing bad characters like '.' and ' '
*/
public static Function toEnvironmentVariableFunction() {
return new Function() {
@Override
public String toString() {
return "toEnvironmentVariableFunction()";
}
@Override
public String apply(String key) {
if (key != null) {
// lets replace any dots in the env var name
return key.replace('.', '_').replace(' ', '_');
}
return null;
}
};
}
/**
* Replaces all occurrencies of the from text with to text without any regular expressions
*/
public static String replaceAllWithoutRegex(String text, String from, String to) {
if (text == null) {
return null;
}
int idx = 0;
while (true) {
idx = text.indexOf(from, 0);
if (idx >= 0) {
text = text.substring(0, idx) + to + text.substring(idx + from.length());
} else {
break;
}
}
return text;
}
}
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