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Java example source code file (SetLastModified.java)

This example Java source code file (SetLastModified.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

can't, exception, file, filechannel, illegalargumentexception, max_position, nio, setlastmodified, succeeded, time, windows

The SetLastModified.java Java example source code

/*
 * Copyright (c) 1998, 2011, 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 4091757 6652379
   @summary Basic test for setLastModified method
 */

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;


public class SetLastModified {

    private static void ck(File f, long nt, long rt) throws Exception {
        if (rt == nt) return;
        if ((rt / 10 == nt / 10)
            || (rt / 100 == nt / 100)
            || (rt / 1000 == nt / 1000)
            || (rt / 10000 == (nt / 10000))) {
            System.err.println(f + ": Time set to " + nt
                               + ", rounded down by filesystem to " + rt);
            return;
        }
        if ((rt / 10 == (nt + 5) / 10)
            || (rt / 100 == (nt + 50) / 100)
            || (rt / 1000 == (nt + 500) / 1000)
            || (rt / 10000 == ((nt + 5000) / 10000))) {
            System.err.println(f + ": Time set to " + nt
                               + ", rounded up by filesystem to " + rt);
            return;
        }
        throw new Exception(f + ": Time set to " + nt
                            + ", then read as " + rt);
    }

    public static void main(String[] args) throws Exception {
        File d = new File(System.getProperty("test.dir", "."));
        File d2 = new File(d, "x.SetLastModified.dir");
        File f = new File(d2, "x.SetLastModified");
        long ot, t;

        /* New time: One week ago */
        long nt = System.currentTimeMillis() - 1000 * 60 * 60 * 24 * 7;

        if (f.exists()) f.delete();
        if (d2.exists()) d2.delete();
        if (!d2.mkdir()) {
            throw new Exception("Can't create test directory " + d2);
        }

        boolean threw = false;
        try {
            d2.setLastModified(-nt);
        } catch (IllegalArgumentException x) {
            threw = true;
        }
        if (!threw)
            throw new Exception("setLastModified succeeded with a negative time");

        ot = d2.lastModified();
        if (ot != 0) {
            if (d2.setLastModified(nt)) {
                ck(d2, nt, d2.lastModified());
                d2.setLastModified(ot);
            } else {
                System.err.println("Warning: setLastModified on directories "
                                   + "not supported");
            }
        }

        if (f.exists()) {
            if (!f.delete())
                throw new Exception("Can't delete test file " + f);
        }
        if (f.setLastModified(nt))
            throw new Exception("Succeeded on non-existent file: " + f);

        // set/check last modified on files of size 1, 1GB+1, 2GB+1, ..
        // On Windows we only test with a tiny file as that platform doesn't
        // support sparse files by default and so the test takes too long.
        final long G = 1024L * 1024L * 1024L;
        final long MAX_POSITION =
            System.getProperty("os.name").startsWith("Windows") ? 0L : 3L*G;
        long pos = 0L;
        while (pos <= MAX_POSITION) {
            try (FileChannel fc = new FileOutputStream(f).getChannel()) {
                fc.position(pos).write(ByteBuffer.wrap("x".getBytes()));
            }
            ot = f.lastModified();
            System.out.format("check with file size: %d\n", f.length());
            if (!f.setLastModified(nt))
                throw new Exception("setLastModified failed on file: " + f);
            ck(f, nt, f.lastModified());
            pos += G;
        }

        if (!f.delete()) throw new Exception("Can't delete test file " + f);
        if (!d2.delete()) throw new Exception("Can't delete test directory " + d2);
    }

}

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