[NIO.2] 第三十七篇 编纂一个文件移动应用

[NIO.2] 第三十七篇 编写一个文件移动应用
移动文件分为两个步骤，先拷贝文件，再删除源文件。

下面的代码将会把  C:\rafaelnadal 目录中的内容移动到 C:\ATP\players\rafaelnafal 目录中。在移动前，要确保 C:\ATP\players\rafaelnafal 目录已经存在。在这个例子中，目录的移动使用了 Files.copy() 和 Files.delete() 方法，文件的移动使用了 Files.move() 方法。

import java.io.IOException; import java.nio.file.FileVisitOption; import java.nio.file.FileVisitResult; import java.nio.file.FileVisitor; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.attribute.BasicFileAttributes; import java.nio.file.attribute.FileTime; import java.util.EnumSet; import static java.nio.file.StandardCopyOption.REPLACE_EXISTING; import static java.nio.file.StandardCopyOption.COPY_ATTRIBUTES; import static java.nio.file.StandardCopyOption.ATOMIC_MOVE;  class MoveTree implements FileVisitor {     private final Path moveFrom;    private final Path moveTo;    static FileTime time = null;     public MoveTree(Path moveFrom, Path moveTo) {         this.moveFrom = moveFrom;         this.moveTo = moveTo;    }     static void moveSubTree(Path moveFrom, Path moveTo) throws IOException {         try {             Files.move(moveFrom, moveTo, REPLACE_EXISTING, ATOMIC_MOVE);         } catch (IOException e) {             System.err.println("Unable to move " + moveFrom + " [" + e + "]");         }     }     @Override    public FileVisitResult postVisitDirectory(Object dir, IOException exc)                                                                       throws IOException {         Path newdir = moveTo.resolve(moveFrom.relativize((Path) dir));         try {             Files.setLastModifiedTime(newdir, time);             Files.delete((Path) dir);         } catch (IOException e) {             System.err.println("Unable to copy all attributes to: " + newdir+" [" + e + "]");         }          return FileVisitResult.CONTINUE;    }     @Override    public FileVisitResult preVisitDirectory(Object dir, BasicFileAttributes attrs)                                                                          throws IOException {         System.out.println("Move directory: " + (Path) dir);         Path newdir = moveTo.resolve(moveFrom.relativize((Path) dir));         try {             Files.copy((Path) dir, newdir, REPLACE_EXISTING, COPY_ATTRIBUTES);             time = Files.getLastModifiedTime((Path) dir);         } catch (IOException e) {             System.err.println("Unable to move " + newdir + " [" + e + "]");             return FileVisitResult.SKIP_SUBTREE;         }         return FileVisitResult.CONTINUE;    }    @Override    public FileVisitResult visitFile(Object file, BasicFileAttributes attrs)                                                                          throws IOException {         System.out.println("Move file: " + (Path) file);         moveSubTree((Path) file, moveTo.resolve(moveFrom.relativize((Path) file)));         return FileVisitResult.CONTINUE;    }    @Override    public FileVisitResult visitFileFailed(Object file, IOException exc)                                                                          throws IOException {         return FileVisitResult.CONTINUE;    } } class Main {     public static void main(String[] args) throws IOException {         Path moveFrom = Paths.get("C:/rafaelnadal");         Path moveTo = Paths.get("C:/ATP/players/rafaelnadal");         MoveTree walk = new MoveTree(moveFrom, moveTo);         EnumSet opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS);         Files.walkFileTree(moveFrom, opts, Integer.MAX_VALUE, walk);     } }当然，也可以不使用 Files.move() 方法，而使用 Files.copy()和 Files.delete() 方法来移动文件：static void moveSubTree(Path moveFrom, Path moveTo) throws IOException {         try {             Files.copy(moveFrom, moveTo, REPLACE_EXISTING, COPY_ATTRIBUTES);             Files.delete(moveFrom);         } catch (IOException e) {             System.err.println("Unable to move " + moveFrom + " [" + e + "]");         }     }

文章来源：http://www.aptusource.org/2014/04/nio-2-writing-a-move-files-application/