注意拷贝路径和复制路径的

用endwith（）来判断目标路径的结尾

用substring（）来剪切复制源路径

用三目运算符简化代码

package comstudy;
 
import java.io.*;
 
public class copydirall {
        public static void main(String [] agrs){
        //copy源
        File srcFile =new File("D:\\testcopy");
        //copy目标
        File destFile = new File("C:\\a\\b\\c\\");
        //调用方法拷贝
       copyDir(srcFile,destFile);
        }
        private static void copyDir(File srcFile,File destFile){
            if(srcFile.isFile()){
                FileInputStream in = null;
                FileOutputStream out = null;
 
                try {
                    in = new FileInputStream(srcFile);
                    String path = (destFile.getAbsolutePath().endsWith("\\") ?
                            destFile.getAbsolutePath():destFile.getAbsolutePath()+ "\\")
                            +srcFile.getAbsolutePath().substring(3);
                    out = new FileOutputStream(path);
                    byte[] bytes = new byte[1024 * 1024];
                    int readCount = 0;
                    while ((readCount = in.read(bytes)) != -1){
                        out.write(bytes,0,readCount);
                    }
                    out.flush();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if(out != null){
                        try {
                            out.close();
                        }catch (IOException e){
                            e.printStackTrace();
                        }
                    }
                    if(in != null){
                        try {
                            in.close();
                        }catch (IOException e){
                            e.printStackTrace();
                        }
                    }
                }
 
                return;
            }
                //获取源下面的子目录
                File[] files = srcFile.listFiles();
               for(File file : files){
//                   System.out.println(file.getAbsolutePath());
                   if(file.isDirectory()){
                    String desDir =  (destFile.getAbsolutePath().endsWith("\\") ?
                            destFile.getAbsolutePath():destFile.getAbsolutePath()+ "\\")
                            +file.getAbsolutePath().substring(3);
                    File newFile  = new File(desDir);
                    if(!newFile.exists()){
                        newFile.mkdirs();
                    }
                   }
                   copyDir(file,destFile);
               }
        }
 
}