public class StreamProgressObj implements StreamProgress {
  @Override
  public void start() {
    System.out.println("copy操作进度开始");
  }
  @Override
  public void progress(long progressSize) {
    System.out.println("当前copy操作进度："+progressSize);
  }
  @Override
  public void finish() {
    System.out.println("copy操作进度结束");
  }
}
public class IoUtilTest {
  @Test
  public void copyTest3(){
    //事先创建源文件，目标文件可以不用创建
    File src = new File("C:\\Users\\Administrator\\Desktop\\xuzhu/copyTest1.txt") ;
    File dest = new File("C:\\Users\\Administrator\\Desktop\\xuzhu/toCopyTest1.txt") ;
    FileWriter fw = null;
    FileReader fr = null;
    try {
      //创建流
      fw = new FileWriter(dest);
      fr = new FileReader(src);
      StreamProgressObj streamProgressObj = new StreamProgressObj();
      IoUtil.copy(fr,fw,1024,streamProgressObj);
    } catch (IOException e) {
      //抛出一个运行时异常(直接停止掉程序)
      throw new RuntimeException("运行时异常",e);
    } finally {
      try {
        //如果是空的 说明流创建失败 失败了不需要关闭
        if (fw != null) {
          fw.close();
        }
      } catch (Exception e) {
        //关闭资源失败 停止程序
        throw new RuntimeException("关闭资源失败");
      }finally {
        try {
          if (fr != null) {
            fr.close();
          }
        } catch (Exception e) {
          throw new RuntimeException("关闭资源失败");
        }
      }
    }
  }
}