jdk/src/share/sample/nio/file/Copy.java
changeset 2057 3acf8e5e2ca0
child 2629 06517d95fadd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/sample/nio/file/Copy.java	Sun Feb 15 12:25:54 2009 +0000
@@ -0,0 +1,217 @@
+/*
+ * Copyright 2008-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     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 Sun Microsystems 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
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import java.nio.file.*;
+import static java.nio.file.StandardCopyOption.*;
+import java.nio.file.attribute.*;
+import static java.nio.file.FileVisitResult.*;
+import java.io.IOException;
+import java.util.*;
+
+/**
+ * Sample code that copies files in a similar manner to the cp(1) program.
+ */
+
+public class Copy {
+
+    /**
+     * Returns {@code true} if okay to overwrite a  file ("cp -i")
+     */
+    static boolean okayToOverwrite(FileRef file) {
+        String answer = System.console().readLine("overwrite %s (yes/no)? ", file);
+        return (answer.equalsIgnoreCase("y") || answer.equalsIgnoreCase("yes"));
+    }
+
+    /**
+     * Copy source file to target location. If {@code prompt} is true then
+     * prompted user to overwrite target if it exists. The {@code preserve}
+     * parameter determines if file attributes should be copied/preserved.
+     */
+    static void copyFile(Path source, Path target, boolean prompt, boolean preserve) {
+        CopyOption[] options = (preserve) ?
+            new CopyOption[] { COPY_ATTRIBUTES, REPLACE_EXISTING } :
+            new CopyOption[] { REPLACE_EXISTING };
+        if (!prompt || target.notExists() || okayToOverwrite(target)) {
+            try {
+                source.copyTo(target, options);
+            } catch (IOException x) {
+                System.err.format("Unable to create: %s: %s%n", target, x);
+            }
+        }
+    }
+
+    /**
+     * A {@code FileVisitor} that copies a file-tree ("cp -r")
+     */
+    static class TreeCopier implements FileVisitor<Path> {
+        private final Path source;
+        private final Path target;
+        private final boolean prompt;
+        private final boolean preserve;
+
+        TreeCopier(Path source, Path target, boolean prompt, boolean preserve) {
+            this.source = source;
+            this.target = target;
+            this.prompt = prompt;
+            this.preserve = preserve;
+        }
+
+        @Override
+        public FileVisitResult preVisitDirectory(Path dir) {
+            // before visiting entries in a directory we copy the directory
+            // (okay if directory already exists).
+            CopyOption[] options = (preserve) ?
+                new CopyOption[] { COPY_ATTRIBUTES } : new CopyOption[0];
+
+            Path newdir = target.resolve(source.relativize(dir));
+            try {
+                dir.copyTo(newdir, options);
+            } catch (FileAlreadyExistsException x) {
+                // ignore
+            } catch (IOException x) {
+                System.err.format("Unable to create: %s: %s%n", newdir, x);
+                return SKIP_SUBTREE;
+            }
+            return CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult preVisitDirectoryFailed(Path dir, IOException exc) {
+            System.err.format("Unable to copy: %s: %s%n", dir, exc);
+            return CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+            if (attrs.isDirectory()) {
+                System.err.println("cycle detected: " + file);
+            } else {
+                copyFile(file, target.resolve(source.relativize(file)),
+                         prompt, preserve);
+            }
+            return CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
+            // fix up modification time of directory when done
+            if (exc == null && preserve) {
+                try {
+                    BasicFileAttributes attrs = Attributes.readBasicFileAttributes(dir);
+                    Path newdir = target.resolve(source.relativize(dir));
+                    Attributes.setLastModifiedTime(newdir,
+                        attrs.lastModifiedTime(), attrs.resolution());
+                } catch (IOException x) {
+                    // ignore
+                }
+            }
+            return CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult visitFileFailed(Path file, IOException exc) {
+            System.err.format("Unable to copy: %s: %s%n", file, exc);
+            return CONTINUE;
+        }
+    }
+
+    static void usage() {
+        System.err.println("java Copy [-ip] source... target");
+        System.err.println("java Copy -r [-ip] source-dir... target");
+        System.exit(-1);
+    }
+
+    public static void main(String[] args) throws IOException {
+        boolean recursive = false;
+        boolean prompt = false;
+        boolean preserve = false;
+
+        // process options
+        int argi = 0;
+        while (argi < args.length) {
+            String arg = args[argi];
+            if (!arg.startsWith("-"))
+                break;
+            if (arg.length() < 2)
+                usage();
+            for (int i=1; i<arg.length(); i++) {
+                char c = arg.charAt(i);
+                switch (c) {
+                    case 'r' : recursive = true; break;
+                    case 'i' : prompt = true; break;
+                    case 'p' : preserve = true; break;
+                    default : usage();
+                }
+            }
+            argi++;
+        }
+
+        // remaining arguments are the source files(s) and the target location
+        int remaining = args.length - argi;
+        if (remaining < 2)
+            usage();
+        Path[] source = new Path[remaining-1];
+        int i=0;
+        while (remaining > 1) {
+            source[i++] = Paths.get(args[argi++]);
+            remaining--;
+        }
+        Path target = Paths.get(args[argi]);
+
+        // check if target is a directory
+        boolean isDir = false;
+        try {
+            isDir = Attributes.readBasicFileAttributes(target).isDirectory();
+        } catch (IOException x) {
+        }
+
+        // copy each source file/directory to target
+        for (i=0; i<source.length; i++) {
+            Path dest = (isDir) ? target.resolve(source[i].getName()) : target;
+
+            if (recursive) {
+                // follow links when copying files
+                EnumSet<FileVisitOption> opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
+                TreeCopier tc = new TreeCopier(source[i], dest, prompt, preserve);
+                Files.walkFileTree(source[i], opts, -1, tc);
+            } else {
+                // not recursive so source must not be a directory
+                try {
+                    if (Attributes.readBasicFileAttributes(source[i]).isDirectory()) {
+                        System.err.format("%s: is a directory%n", source[i]);
+                        continue;
+                    }
+                } catch (IOException x) { }
+                copyFile(source[i], dest, prompt, preserve);
+            }
+        }
+    }
+}