Java 示例 - 复制文件

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  问题描述

  如何将一个文件复制到另一个文件中？
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  解决方案

  此示例显示如何使用 BufferedWriter 类的读写方法将一个文件的内容复制到另一个文件中。

  
  import java.io.*;
  public class Main {
     public static void main(String[] args) throws Exception {
        BufferedWriter out1 = new BufferedWriter(new FileWriter("srcfile"));
        out1.write("string to be copied\n");
        out1.close();
        InputStream in = new FileInputStream(new File("srcfile"));
        OutputStream out = new FileOutputStream(new File("destnfile"));
        byte[] buf = new byte[1024];
        int len;
        
        while ((len = in.read(buf)) > 0) {
           out.write(buf, 0, len);
        }
        in.close();
        out.close();
        BufferedReader in1 = new BufferedReader(new FileReader("destnfile"));
        String str;
        
        while ((str = in1.readLine()) != null) {
           System.out.println(str);
        }
        in.close();
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。

  
  string to be copied
  

  下面是在java中复制一个文件到另一个文件的另一个示例

  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
   
  public class CopyExample {
     public static void main(String[] args) {
        FileInputStream ins = null;
        FileOutputStream outs = null;
        try {
           File infile = new File("C:\\Users\\TutorialsPoint7\\Desktop\\abc.txt");
           File outfile = new File("C:\\Users\\TutorialsPoint7\\Desktop\\bbc.txt");
           ins = new FileInputStream(infile);
           outs = new FileOutputStream(outfile);
           byte[] buffer = new byte[1024];
           int length;
           
           while ((length = ins.read(buffer)) > 0) {
              outs.write(buffer, 0, length);
           } 
           ins.close();
           outs.close();
           System.out.println("File copied successfully!!");
        } catch(IOException ioe) {
           ioe.printStackTrace();
        } 
     }
  }
  

  上面的代码示例将产生以下结果。

  
  File copied successfully!!