文件的拷贝

package FileStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;public class CopyDemo {public static void main(String[] args) throws Exception {// 1 创建源,目标File srcFile = new File("file/stream.txt");File destFile = new File("file/stream_copy.txt");// 2 创建输入的管道（输入流对象 / 输出流对象）InputStream in = new FileInputStream(srcFile);OutputStream out = new FileOutputStream(destFile);// 3 读取 / 写出 操作byte[] buffer = new byte[3];//创建容量为10的缓冲区，存储已经读取的字节数据int len = -1;//表示已经读取了多少字节数，如果是-1表面文件读到最后//len = in.read(buffer);//表面读取了多少个字节while((len = in.read(buffer)) != -1){System.out.println(new String(buffer, 0 ,len));out.write(buffer, 0, len);}// 4 关闭管道（关闭资源）in.close();out.close();}}