io.bdeploy.common.util.StringHelper Maven / Gradle / Ivy
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package io.bdeploy.common.util;
/**
* Helper for {@link java.lang.String}
*/
public class StringHelper {
private StringHelper() {
}
/**
* Returns whether the given string is null or empty
*/
public static boolean isNullOrEmpty(String s) {
return s == null || s.isEmpty();
}
/**
* Checks if the string contains only lowercase characters.
*/
public static boolean isAllLowerCase(String s) {
if (s.trim().isEmpty()) {
return true;
}
for (int i = 0; i < s.length(); i++) {
if (!Character.isLowerCase(s.charAt(i))) {
return false;
}
}
return true;
}
/**
* Returns a string whose value is the concatenation of this
* string repeated {@code count} times.
*
* If this string is empty or count is zero then the empty
* string is returned.
*
* This is less efficient than the Java 11 implementation as we
* cannot reuse the original Strings encoding to fill arrays.
*
* @param count number of times to repeat
* @return A string composed of this string repeated
* {@code count} times or the empty string if this
* string is empty or count is zero
* @throws IllegalArgumentException if the {@code count} is
* negative.
*/
public static String repeat(String string, int count) {
if (count < 0) {
throw new IllegalArgumentException("count is negative: " + count);
}
if (count == 1) {
return string;
}
byte[] value = string.getBytes();
final int len = value.length;
if (len == 0 || count == 0) {
return "";
}
if (Integer.MAX_VALUE / count < len) {
throw new OutOfMemoryError(
"Repeating " + len + " bytes String " + count + " times will produce a String exceeding maximum size.");
}
StringBuilder builder = new StringBuilder(string.length() * count);
while (count-- > 0) {
builder.append(string);
}
return builder.toString();
}
}