IO流文件复制

1.文件复制

package Java10;

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

//文件复制
public class Test07 {
    
    public static void main(String[] args) throws IOException {
    
        copy("D:\\a", "D:\\b");
    }

    public static void copy(String src, String dest) throws IOException {
    
        Path p1 = Paths.get(src);
        Path p2 = Paths.get(dest);

        //判断复制路径是否存在
        if (!Files.exists(p1)) {
    
            return;
        } else {
    
            //判断文件是否是目录
            if (Files.isDirectory(p1)) {
    
                Files.walkFileTree(p1, new FileVisitor<Path>() {
    
                    //创建文件的目录
                    @Override
                    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
    
                        //根据当前路径和给定的路径，构造两个路径之间的相对路径
                        Path rpath = p1.relativize(dir);
                        //两个路径相加
                        Path newPath = p2.resolve(rpath);
                        //判断新路径是否存在
                        if (!Files.exists(newPath)) {
    
                            Files.createDirectories(newPath);
                        }
                        return FileVisitResult.CONTINUE;
                    }

                    //创建对应的文件
                    @Override
                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
    
                        Path rpath = p1.relativize(file);
                        Path newPath = p2.resolve(rpath);
                        Files.copy(file, newPath);
                        return FileVisitResult.CONTINUE;
                    }

                    @Override
                    public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
    
                        return FileVisitResult.CONTINUE;
                    }

                    @Override
                    public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
    
                        return FileVisitResult.CONTINUE;
                    }
                });
            }
        }
    }
}