使用OutputStream＆（DataOutPutStream或PrintWriter）时出现问题

I wrote a simple server using java socket programming and intended to make that offered 2 files for download and display some html response when the download finished. What I did is use PrintWriter.print or DataOutPutStream.writeBytes to send the string including html tags and response string to the browser, then use OutputStream.write to send the file requested. The URL I typed in the browser was like 127.0.0.1/test1.zip, relevant code fragments as following:I wrote a simple server using java socket progr