Java example source code file (ConstValInit.java)

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Java - Java tags/keywords

class, constvalinit, exception, failed, string, test

The ConstValInit.java Java example source code

/*
 * Copyright (c) 1999, 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 4253590
 * @summary Verify that non-static constant fields are initialized correctly.
 *          Also, while a runtime initialization is required, verify that
 *          references to such fields via a simple variable are correctly
 *          recognized as constant expressions.
 * @author maddox (adapted from bug report)
 *
 * @run compile ConstValInit.java
 * @run main ConstValInit
 */

public class ConstValInit {

    public final String fnl_str = "Test string";

    public final int fnl_int = 1;

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

        Class checksClass = Class.forName("ConstValInit");
        ConstValInit checksObject = (ConstValInit)(checksClass.newInstance());
        String reflected_fnl_str = (String)checksClass.getField("fnl_str").get(checksObject);
        if (!checksObject.fnl_str.equals(reflected_fnl_str)) {
            throw new Exception("FAILED: ordinary and reflected field values differ");
        }

    }

    void foo() {
        // Statement below will not compile if fnl_int is not recognized
        // as a constant expression.
        switch (1) {
            case fnl_int: break;
        }
    }

}