JAVA练习笔记---copyfile

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class Collection {
    public static void main(String[] args) throws FileNotFoundException, IOException{
        File file = new File("D:/","copy1223.txt");//创建一个新的文件
        InputStream input=new FileInputStream("D:/1223.txt");// 读入一个原有的文件
        byte[] b=new byte[2048];
        input.read(b);  //把文件读到B中
        input.close(); //必须关闭
        
        OutputStream output=new FileOutputStream("D:/copy1223.txt");
        output.write(b); //把B中的文件写入copy123中
        output.close(); //必须关闭
        
      }
    
}




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/*
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 * and open the template in the editor.
 */
package testSet;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Administrator
 */
public class FileCopy {

    public static void main(String[] args){
        File file = new File("D:/inst.exe");
        File target = new File("D:/copy"+file.getName());
        copyFile(file.getPath(),target.getPath());
    }
    public static void copyFile(String file, String targetfile) {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        File source = new File(file);
        if (!source.exists()) {
            System.err.println("File not exists!");
            return;
        }
        try {
            fis = new FileInputStream(file);
            fos = new FileOutputStream(targetfile);
            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = fis.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
                fos.flush();
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(FileCopy.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(FileCopy.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            try {
                if (fis != null) {

                    fis.close();
                }
                if (fos != null) {
                    fos.close();
                }
            } catch (IOException ex) {
                Logger.getLogger(FileCopy.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}