1 /*

     2  * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 import sun.hotspot.WhiteBox;

    26 

    27 public class InternStringTest {

    28     public static String passed_output1 = "Found shared string.";

    29     public static String passed_output2 = "Shared strings are equal.";

    30     public static String passed_output3 = "Found shared string containing latin1 supplement chars.";

    31     public static String passed_output4 = "Found shared string containing non-western chars.";

    32     public static final String latin1Sup  = "XXXX \u00a3 YYYY"; // \u00a3 = The pound sign

    33     public static final String nonWestern = "XXXX \u5678 YYYY"; // \u5678 = Unicode Han Character 'ton (metric or English)'

    34 

    35     public static void main(String[] args) throws Exception {

    36         WhiteBox wb = WhiteBox.getWhiteBox();

    37 

    38         // All string literals are shared.

    39         String shared1 = "LiveOak";

    40         String interned1 = shared1.intern();

    41         if (wb.areSharedStringsIgnored() || wb.isShared(interned1)) {

    42             System.out.println(passed_output1);

    43         } else {

    44             throw new RuntimeException("Failed: String is not shared.");

    45         }

    46 

    47         // Test 2: shared_string1.intern() == shared_string2.intern()

    48         String shared2 = "LiveOak";

    49         String interned2 = shared2.intern();

    50         if (interned1 == interned2) {

    51             System.out.println(passed_output2);

    52         } else {

    53             throw new RuntimeException("Not equal!");

    54         }

    55 

    56         // Test 3: interned strings with a char in latin1 supplement block [\u0080-\u00ff]

    57         {

    58             String a = "X" + latin1Sup.substring(1);

    59             String b = a.intern();

    60 

    61             if (wb.areSharedStringsIgnored() || wb.isShared(b)) {

    62                 System.out.println(passed_output3);

    63             } else {

    64                 throw new RuntimeException("Failed: expected shared string with latin1-supplement chars.");

    65             }

    66         }

    67 

    68         // Test 5: interned strings with non-western characters

    69         {

    70             String a = "X" + nonWestern.substring(1);

    71             String b = a.intern();

    72             if (wb.areSharedStringsIgnored() || wb.isShared(b)) {

    73                 System.out.println(passed_output4);

    74             } else {

    75                 throw new RuntimeException("Failed: expected shared string with non-western chars.");

    76             }

    77         }

    78     }

    79 }