将不同文件目录下的文件复制到一个指定目录

如代码所示：

    public static void main(String[] args) throws Exception {
        String dir = "E:\project\dir1";
        String outDir = "E:\project\dir2";
        File input = new File(dir);
        for(File f : input.listFiles()){
            for(File ff : f.listFiles()){
                if(ff.getName().contains("test")){
                    String fileName = ff.getName();
                    System.out.println(fileName);
                    System.out.println(ff.toPath());
                    Files.copy(ff.toPath(), Paths.get(outDir + File.separator + fileName));
                }
            }
        }
    }

源文件：E:\project\dir1\dir11\test.docx、E:\project\dir1\dir22\test.xlsx

注：目标目录必须存在

若目标目录存在同一文件，可指定调用：

Files.copy(ff.toPath(), Paths.get(outDir + File.separator + fileName), StandardCopyOption.REPLACE_EXISTING);

Files.copy函数源码：

public static Path copy(Path source, Path target, CopyOption... options)
        throws IOException
    {
        FileSystemProvider provider = provider(source);
        if (provider(target) == provider) {
            // same provider
            provider.copy(source, target, options);
        } else {
            // different providers
            CopyMoveHelper.copyToForeignTarget(source, target, options);
        }
        return target;
    }

CopyOption参数可填：

public enum StandardCopyOption implements CopyOption {
    /**
     * Replace an existing file if it exists.
     */
    REPLACE_EXISTING,
    /**
     * Copy attributes to the new file.
     */
    COPY_ATTRIBUTES,
    /**
     * Move the file as an atomic file system operation.
     */
    ATOMIC_MOVE;
}