java使用 io 流进行文件的简单复制:

使用 io 流进行文件的简单复制:

test.txt 内容为：

I love Java, I love JavaI love Java, I love JavaI love Java, I love JavaI love Java, I love JavaI love Java, I love Java

代码：

import java.io.*; public class Test {     public static void main(String[] args) {         File sourcefile = new File("./test.txt");         File copyfile = new File("./testcopy.txt");         FileInputStream fileInputStream = null;// 从文件中读数据         FileOutputStream fileOutputStream = null;// 用于把数据写入文件         BufferedWriter bufferedWriter = null;// 用于把数据写入文件         try {             if (!sourcefile.exists()) {                 sourcefile.createNewFile();                 bufferedWriter = new BufferedWriter(new FileWriter(sourcefile));                 // bufferedwriter 自动追加数据                 String s = new String(" I love Java");                 char bchar[] = s.toCharArray();                 for (int i = 0; i < 5; i++) {                     // 两种方式往文件中写数据                     bufferedWriter.write(bchar, 0, bchar.length);                     bufferedWriter.write(", " + s + "\n");                 }                 // 写完之后才能关闭流,                 bufferedWriter.flush();                 bufferedWriter.close();             }             copyfile.createNewFile();             fileInputStream = new FileInputStream(sourcefile);             fileOutputStream = new FileOutputStream(copyfile);             byte b[] = new byte[8192];             int len = b.length;             while ((len = fileInputStream.read(b, 0, len)) > 0) {                 fileOutputStream.write(b, 0, len);                 fileOutputStream.flush();             }             System.out.println("file copied");             fileInputStream.close();             fileOutputStream.close();         } catch (IOException e) {             e.printStackTrace();         }     } }

执行程序，可以看到创建了一个 testcopy.txt 文件，内容为：

I love Java, I love JavaI love Java, I love JavaI love Java, I love JavaI love Java, I love JavaI love Java, I love Java