使用Files.copy复制
/* 来 自* N o w J a v a . c o m */ 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.*; public class Main{ 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)//from nowjava.com // 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; 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 = Files.isDirectory(target); // copy each source file/directory to target for (i = 0; i < source.length; i++) { Path dest = (isDir) ? target.resolve(source[i].getFileName()) : 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, Integer.MAX_VALUE, tc); } else { // not recursive so source must not be a directory if (Files.isDirectory(source[i])) { System.err.format("%s: is a directory%n", source[i]); continue; } copyFile(source[i], dest, prompt, preserve); } } } /** * Returns {@code true} if okay to overwrite a file ("cp -i") */ static boolean okayToOverwrite(Path 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 * prompt 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 || Files.notExists(target) || okayToOverwrite(target)) { try { Files.copy(source, target, options); } catch (IOException x) { System.err.format("Unable to copy: %s: %s%n", source, 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, BasicFileAttributes attrs) { // 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 { Files.copy(dir, 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 visitFile(Path file, BasicFileAttributes attrs) { 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) { Path newdir = target.resolve(source.relativize(dir)); try { FileTime time = Files.getLastModifiedTime(dir); Files.setLastModifiedTime(newdir, time); } catch (IOException x) { System.err.format( "Unable to copy all attributes to: %s: %s%n", newdir, x); } } return CONTINUE; } @Override public FileVisitResult visitFileFailed(Path file, IOException exc) { if (exc instanceof FileSystemLoopException) { System.err.println("cycle detected: " + file); } else { System.err.format("Unable to copy: %s: %s%n", file, exc); } return CONTINUE; } } static void usage() { System.err.println(