java从一个目录拷贝文件或整个文件夹到另一个目录下

**
* 复制单个文件
* @param oldPath String 原文件路径 如：c:/fqf.txt
* @param newPath String 复制后路径 如：f:/fqf.txt
* @return boolean
*/
public void copyFile(String oldPath, String newPath) {
try {
int bytesum = 0;
int byteread = 0;
File oldfile = new File(oldPath);
if (oldfile.exists()) { //文件存在时
InputStream inStream = new FileInputStream(oldPath); //读入原文件
FileOutputStream fs = new FileOutputStream(newPath);
byte[] buffer = new byte[1444];
int length;
while ( (byteread = inStream.read(buffer)) != -1) {
bytesum += byteread; //字节数 文件大小
System.out.println(bytesum);
fs.write(buffer, 0, byteread);
}
inStream.close();
}
}
catch (Exception e) {
System.out.println("复制单个文件操作出错");
e.printStackTrace(); 

} 

} 

/**
* 复制整个文件夹内容
* @param oldPath String 原文件路径 如：c:/fqf
* @param newPath String 复制后路径 如：f:/fqf/ff
* @return boolean
*/
public void copyFolder(String oldPath, String newPath) { 

try {
(new File(newPath)).mkdirs(); //如果文件夹不存在 则建立新文件夹
File a=new File(oldPath);
String[] file=a.list();
File temp=null;
for (int i = 0; i < file.length; i++) {
if(oldPath.endsWith(File.separator)){
temp=new File(oldPath+file[i]);
}
else{
temp=new File(oldPath+File.separator+file[i]);
} 

if(temp.isFile()){
FileInputStream input = new FileInputStream(temp);
FileOutputStream output = new FileOutputStream(newPath + "/" +
(temp.getName()).toString());
byte[] b = new byte[1024 * 5];
int len;
while ( (len = input.read(b)) != -1) {
output.write(b, 0, len);
}
output.flush();
output.close();
input.close();
}
if(temp.isDirectory()){//如果是子文件夹
copyFolder(oldPath+"/"+file[i],newPath+"/"+file[i]);
}
}
}
catch (Exception e) {
System.out.println("复制整个文件夹内容操作出错");
e.printStackTrace(); 

} 

}

原文地址：https://www.cnblogs.com/momo1210/p/9483259.html