字节流拷贝WORD文件后打不开，报错

Question

请问，代码中是哪里有问题吗? 拷贝后的word文件打不开，报错，buff这个变量，read(buff)之后，读的字节并没有赋给谁，那write（buff）也是写的buff,可是读的内容并没有赋给buff呀，是怎么能写出去呢，难道write能识别刚读进内存中的字节吗，懵，求指点，此word文档中有图片，难道是因为这吗？可是字节流可以读图片吧？

```java
package outputstream;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * @author 小池
 * @version 1.0
 */
public class BufferedOutputStreamCopy {
    public static void main(String[] args) throws Exception {
        int readLen = 0;
        byte[] buff = new byte[1024];
        String orgPath = "D:\\java八股文.docx";
        String destPath = "D:\\java八股文副本.docx";
        BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(orgPath));
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(destPath));
        while ((readLen = bufferedInputStream.read(buff)) != -1) {
            bufferedOutputStream.write(buff, 0, readLen);
        }
        if (bufferedInputStream != null) {
            bufferedInputStream.close();
        }
        if (bufferedOutputStream != null) {
            bufferedOutputStream.close();
        }

    }

}

```

Answer 1

代码层面没有问题，试着跑了一下，复制的文件pptx、docx都可以正常打开。
应该跟你的环境有关，JDK版本、IDE版本等等
buff的赋值是read方法内部处理的，处理了多少字节数据由返回值确定。