这个poi把String写入word文档后，打开文档就报“打开文件错误”，求高人解决下

import java.io.ByteArrayInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.poi.poifs.filesystem.DirectoryEntry;
import org.apache.poi.poifs.filesystem.DocumentEntry;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

public class writeWord{
public static void main(String[] args) throws IOException{
byte[] a=new String("看见了！").getBytes("GBK");
ByteArrayInputStream bs = new ByteArrayInputStream(a);
POIFSFileSystem fs = new POIFSFileSystem();
///////////////////////////////////
DirectoryEntry directory = fs.getRoot();
DocumentEntry de = directory.createDocument("WordDocument", bs);
//以上两句代码不能省略，否则输出的是乱码
FileOutputStream fos = new FileOutputStream("D:\text111.doc");
fs.writeFilesystem(fos);
bs.close();
//fos.flush();
fos.close();
System.out.println("操作成功！");
}

}