开发中使用缓冲流替换基本流。
@Test public void method() throws IOException { //1.创建文件 File file1 = new File("test1.png"); File file2 = new File("test2.png"); //2.创建流 //2.1创建节点流 FileInputStream fileInputStream = new FileInputStream(file1); FileOutputStream fileOutputStream = new FileOutputStream(file2); //2.2创建缓冲流 BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream); BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream); // the number of bytes to write. int len = 0; //每次读的字节数为10 byte[] bytes = new byte[10]; while ((len = bufferedInputStream.read(bytes)) != -1){ //写 bufferedOutputStream.write(bytes,0,len); } System.out.println("复制成功"); //关闭流的顺序，先关闭外层的流，再关闭内层的流 bufferedInputStream.close(); bufferedOutputStream.close(); //fileInputStream.close(); //fileOutputStream.close(); } 注意：先关闭外面的流，在关闭内从的流，实际上在关闭外层流的同时，内层的流也会进行关闭，所以关于内层流的关闭可以省略。实际开发中使用try catch finally 确保关闭流。缓冲流的作用是提高文件的读取和写入速度，提高读写速度的原因是：内部提供了一个缓冲区。