/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* See LICENSE.txt included in this distribution for the specific
* language governing permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at LICENSE.txt.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2008, 2014, Oracle and/or its affiliates. All rights reserved.
*/
package org.opensolaris.opengrok.util;
import java.util.regex.Pattern;
/**
* Various String utility methods.
*
* @author austvik
*/
public final class StringUtils {
private StringUtils() {
// Only static utility methods
}
/**
* Returns true if the string is empty or only includes whitespace characters.
*
* @param str the string to be checked
* @return true if string is empty or only contains whitespace characters
*/
public static boolean isOnlyWhitespace(String str) {
for (int i = 0; i < str.length(); i++) {
if (!Character.isWhitespace(str.charAt(i))) {
return false;
}
}
return true;
}
static final Pattern javaClassPattern =
Pattern.compile("([a-z][A-Za-z]*\\.)+[A-Z][A-Za-z0-9]*");
/**
* Returns true if the string is possibly a full java class name
*
* @param s the string to be checked
* @return true if string could be a java class name
*/
public static boolean isPossiblyJavaClass(String s) {
// Only match a small subset of possible class names to prevent false
// positives:
// - class must be qualified with a package name
// - only letters in package name, starting with lower case
// - class name must be in CamelCase, starting with upper case
return javaClassPattern.matcher(s).matches();
}
/**
* Convert value in milliseconds to readable time.
* @param time_ms delta in milliseconds
* @return human readable string
*/
public static String getReadableTime(long time_ms) {
String output = "";
long time_delta = time_ms;
int milliseconds = (int) (time_delta % 1000);
time_delta /= 1000;
int seconds = (int) (time_delta % 60);
time_delta /= 60;
int minutes = (int) (time_delta % 60);
time_delta /= 60;
int hours = (int) (time_delta % 24);
int days = (int) (time_delta / 24);
if (days != 0) {
output += String.format("%d day", days);
if (days > 1) {
output += "s";
}
if ((hours != 0) || (minutes != 0) || (seconds != 0)) {
output += " ";
}
}
if ((hours != 0) || (minutes != 0)) {
return output + String.format("%d:%02d:%02d", hours, minutes, seconds);
}
if (seconds != 0) {
return output + String.format("%d.%d seconds", seconds, milliseconds);
}
if (milliseconds != 0) {
return output + String.format("%d ms", milliseconds);
}
return (output.length() == 0 ? "0" : output);
}
}