/*
* Copyright 2013 serso aka se.solovyev
*
* Licensed 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.
*
* ---------------------------------------------------------------------
* Contact details
*
* Email: se.solovyev@gmail.com
* Site: http://se.solovyev.org
*/
package org.solovyev.common.text;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Date;
import java.util.Random;
public class Strings {
public static final String LINE_SEPARATOR = System.getProperty("line.separator");
public static final Character[] EMPTY_CHARACTER_OBJECT_ARRAY = new Character[0];
// random variable: must be synchronized in usage
private static final Random RANDOM = new Random(new Date().getTime());
// not intended for instantiation
protected Strings() {
throw new AssertionError();
}
public static boolean isEmpty(@Nullable CharSequence s) {
return s == null || s.length() == 0;
}
@Nonnull
public static String getNotEmpty(@Nullable CharSequence s, @Nonnull String defaultValue) {
return isEmpty(s) ? defaultValue : s.toString();
}
@Nonnull
public static Character[] toObjects(char[] array) {
if (array == null || array.length == 0) {
return EMPTY_CHARACTER_OBJECT_ARRAY;
}
final Character[] result = new Character[array.length];
for (int i = 0; i < array.length; i++) {
result[i] = array[i];
}
return result;
}
@Nonnull
public static String generateRandomString(int length) {
final StringBuilder result = new StringBuilder(length);
for (int i = 0; i < length; i++) {
final char ch;
synchronized (RANDOM) {
// 'A' = 65
ch = (char) (RANDOM.nextInt(52) + 65);
}
result.append(ch);
}
return result.toString();
}
}