--- a/src/java.base/share/classes/java/lang/String.java Wed May 16 15:25:51 2018 +0200
+++ b/src/java.base/share/classes/java/lang/String.java Fri May 18 08:43:49 2018 -0300
@@ -2729,6 +2729,31 @@
}
/**
+ * Returns {@code true} if the string is empty or contains only
+ * {@link Character#isWhitespace(int) white space} codepoints,
+ * otherwise {@code false}.
+ *
+ * @return {@code true} if the string is empty or contains only
+ * {@link Character#isWhitespace(int) white space} codepoints,
+ * otherwise {@code false}
+ *
+ * @see Character#isWhitespace(int)
+ *
+ * @since 11
+ */
+ public boolean isBlank() {
+ return indexOfNonWhitespace() == length();
+ }
+
+ private int indexOfNonWhitespace() {
+ if (isLatin1()) {
+ return StringLatin1.indexOfNonWhitespace(value);
+ } else {
+ return StringUTF16.indexOfNonWhitespace(value);
+ }
+ }
+
+ /**
* This object (which is already a string!) is itself returned.
*
* @return the string itself.
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/lang/String/IsBlank.java Fri May 18 08:43:49 2018 -0300
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+/**
+ * @test
+ * @summary Basic isBlank functionality
+ * @bug 8200436
+ * @run main/othervm IsBlank
+ */
+
+public class IsBlank {
+ public static void main(String... arg) {
+ testIsBlank();
+ testWhitespace();
+ }
+
+ /*
+ * Test with strings
+ */
+ static void testIsBlank() {
+ test("", true);
+ test(" ", true);
+ test(" \t", true);
+ test(" \u1680", true);
+ test(" abc ", false);
+ test(" abc\u2022", false);
+ }
+
+ /*
+ * Test full whitespace range
+ */
+ static void testWhitespace() {
+ StringBuilder sb = new StringBuilder(64);
+ IntStream.range(1, 0xFFFF).filter(c -> Character.isWhitespace(c))
+ .forEach(c -> sb.append((char)c));
+ String whiteSpace = sb.toString();
+
+ test(whiteSpace, true);
+ test(whiteSpace + "abc" + whiteSpace, false);
+ }
+
+ /*
+ * Raise an exception if the two inputs are not equivalent.
+ */
+ static void test(String input, boolean expected) {
+ if (input.isBlank() != expected) {
+ System.err.format("Failed test, Input: %s, Expected: %b%n", input, expected);
+ throw new RuntimeException();
+ }
+ }
+}