java 文件操作

 

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;

public class FileOper {

  public void copyFile(String oldPath, String newPath) {
  try {
   int bytesum = 0;
   int byteread = 0;
   File oldfile = new File(oldPath);
   if (oldfile.exists()) {
    InputStream inStream = new FileInputStream(oldPath); //读入原文件
    FileOutputStream fs = new FileOutputStream(newPath);
    //这里是字节数，是8个位，每一个位是0或者1的字符
    //汉字输入状态下一个逗号是2个字节，英文状态下是一个字节
    byte[] buffer = new byte[30];
    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){
   
  }
 }
 
  public static void main(String args[]){
   FileOper fo = new FileOper();
   fo.copyFile("D:\\source.txt", "D:\\copySource.txt");
  }

}

      /**
 * 复制整个文件夹内容
*/
 public void copyFolder(String oldPath, String newPath) {
 try {
 (new File(newPath)).mkdirs();

 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) {
  e.printStackTrace();
 }
 }
 /**
 * 移动文件到指定目录
*/
 public void moveFile(String oldPath, String newPath) {
 copyFile(oldPath, newPath);
 //删除源文件 }