src/share/sample/nio/file/DiskUsage.java

/*
 * Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved.
 *
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 *
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 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 */

import java.nio.file.*;
import java.nio.file.attribute.*;
import java.io.IOException;

/**
 * Example utility that works like the df(1M) program to print out disk space
 * information
 */

public class DiskUsage {

    static final long K = 1024;

    static void printFileStore(FileStore store) throws IOException {
        FileStoreSpaceAttributes attrs = Attributes.readFileStoreSpaceAttributes(store);

        long total = attrs.totalSpace() / K;
        long used = (attrs.totalSpace() - attrs.unallocatedSpace()) / K;
        long avail = attrs.usableSpace() / K;

        String s = store.toString();
        if (s.length() > 20) {
            System.out.println(s);
            s = "";
        }
        System.out.format("%-20s %12d %12d %12d\n", s, total, used, avail);
    }

    public static void main(String[] args) throws IOException {
        System.out.format("%-20s %12s %12s %12s\n", "Filesystem", "kbytes", "used", "avail");
        if (args.length == 0) {
            FileSystem fs = FileSystems.getDefault();
            for (FileStore store: fs.getFileStores()) {
                printFileStore(store);
            }
        } else {
            for (String file: args) {
                FileStore store = Paths.get(file).getFileStore();
                printFileStore(store);
            }
        }
    }
}