学习IO和递归，写了个拷贝文件的Demo - 黑马程序员技术交流社区

package cn.itcast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.util.Scanner;
public class CopyDemo {
public static void main(String[] args){
//String src = "G:\\temp"; 将这两个字符串改由Scanner接收
//String dest = "F:";
Scanner sc = new Scanner(System.in);
System.out.println("请输入需要被拷贝的文件夹的路径（路径中斜杠请使用双斜杠）:");
String src = sc.next();
System.out.println("请输入拷贝目标位置：");
String dest = sc.next();
File srcfile = new File(src);
File destfile = new File(dest);
try{
copy(srcfile,destfile);
}catch(Exception e){
throw new RuntimeException("拷贝文件失败，请检查源文件或者目标位置是否存在");
}
System.out.println("拷贝完毕，请查看。");
}
public static void copy(File srcfile,File destfile) throws Exception{
//在目标位置创建同名文件夹
File newDir = new File(destfile,srcfile.getName());
newDir.mkdir();
//遍历源文件夹
File[] subFiles = srcfile.listFiles();
for (File subfile : subFiles) {
// 输出文件名，测试文件是否遍历成功
String name = subfile.getName();
System.out.println(name);
//如果是文件，直接拷贝
if(subfile.isFile()){
FileInputStream fileInputStream = new FileInputStream(subfile);
FileOutputStream fileOutputStream = new FileOutputStream(new File(newDir,subfile.getName()));
int i = 0;
byte [] arr = new byte[1024];
while((i = fileInputStream.read(arr)) != -1){
fileOutputStream.write(arr,0,i);
fileOutputStream.flush();
}
fileInputStream.close();
fileOutputStream.close();
//如果不是文件夹，递归调用拷贝方法
}else{
copy(subfile,newDir);
}
}
}
}

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