ToStringCache.java

/*
 * Copyright (c) 2013, 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.
 */

/* @test
 * @bug 8013395 8014814
 * @summary Test StringBuffer.toString caching
 */

public class ToStringCache {

    // we can't test that we actually use a cached value (the benchmarks
    // verify that) but we have to test that the cache is cleared when
    // expected

    public static void main(String[] args) throws Exception {
        String original = "The original String";

        StringBuffer sb = new StringBuffer(original);

        String a = sb.toString();
        checkEqual(a, original);

        String b = sb.toString();
        checkEqual(a, b);

        // mutating methods

        sb.setLength(12);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.setCharAt(0, 'X');
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(new Character('X'));
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append("More text");
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(sb);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(new StringBuilder("Build"));
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(new StringBuilder("Build2"), 0, 1);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(new char[] { 'a', 'b' });
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(true);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append('c');
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(23);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.appendCodePoint(Character.codePointAt(new char[] { 'X'}, 0));
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(1L);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(1.0f);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append(1.0d);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.delete(0, 5);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.deleteCharAt(0);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.replace(0,2, "123");
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, new char[] { 'a', 'b', 'c'}, 0, 3);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, new Object());
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, "abc");
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, new char[] { 'a', 'b', 'c' });
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, new StringBuilder("Build"));
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, new StringBuilder("Build"), 0, 1);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, false);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, 'X');
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, 1);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, 1L);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, 1.0f);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.insert(0, 1.0d);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.reverse();
        b = sb.toString();
        checkUnequal(a, b);

        // Extra checks that append(null) works correctly

        sb.append((String)null);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append((StringBuffer)null);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append((StringBuilder)null);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        sb.append((CharSequence)null);
        b = sb.toString();
        checkUnequal(a, b);
        a = b;

        // non-mutating methods

        // Reset to known value
        sb = new StringBuffer(original);
        a = sb.toString();
        b = sb.toString();
        checkEqual(a, b);

        int l = sb.length();
        b = sb.toString();
        checkEqual(a, b);

        int cap = sb.capacity();
        b = sb.toString();
        checkEqual(a, b);

        sb.ensureCapacity(100);
        b = sb.toString();
        checkEqual(a, b);

        sb.trimToSize();
        b = sb.toString();
        checkEqual(a, b);

        char c = sb.charAt(1);
        b = sb.toString();
        checkEqual(a, b);

        int cp = sb.codePointAt(1);
        b = sb.toString();
        checkEqual(a, b);

        cp = sb.codePointBefore(2);
        b = sb.toString();
        checkEqual(a, b);

        int count = sb.codePointCount(0,1);
        b = sb.toString();
        checkEqual(a, b);

        count = sb.offsetByCodePoints(0, 1);
        b = sb.toString();
        checkEqual(a, b);

        sb.getChars(0, 1, new char[2], 0);
        b = sb.toString();
        checkEqual(a, b);

        String sub = sb.substring(0);
        b = sb.toString();
        checkEqual(a, b);

        CharSequence cs = sb.subSequence(0,1);
        b = sb.toString();
        checkEqual(a, b);

        sub = sb.substring(0, 3);
        b = sb.toString();
        checkEqual(a, b);

        int index = sb.indexOf("rig");
        b = sb.toString();
        checkEqual(a, b);

        index = sb.indexOf("rig", 2);
        b = sb.toString();
        checkEqual(a, b);

        index = sb.lastIndexOf("rig");
        b = sb.toString();
        checkEqual(a, b);

        index = sb.lastIndexOf("rig", 3);
        b = sb.toString();
        checkEqual(a, b);

    }

    private static void checkEqual(String s1, String s2) {
        if (!s1.equals(s2))
            throw new RuntimeException("Unmatched strings: s1 = "
                                       + s1 + " s2 = " + s2);
    }
    private static void checkUnequal(String s1, String s2) {
        if (s1.equals(s2))
            throw new RuntimeException("Unexpected matched strings: " + s1);
    }
}