後臺將文件內容直接通過流寫入到頁面

前端頁面訪問後臺，後臺直接讀取文件，通過文件流將文件寫入到頁面
如：E://upload/index.html

    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;

    @RequestMapping(value="tempDownLoad")
    public void tempDownLoad(HttpServletRequest request,HttpServletResponse response){

        InputStream in = null;
        try{
            in = new FileInputStream("E://upload/index.html");
            byte[] buffer = new byte[1024];
            int bytesRead = 0;
            do {
                bytesRead = in.read(buffer, 0, buffer.length);
                response.getOutputStream().write(buffer, 0, bytesRead);
            } while (bytesRead == buffer.length);

        } catch (Exception e) {  


        }finally{
            try {
                if (in != null) {
                    in.close();
                }
                response.getOutputStream().flush();
            } catch (IOException e) {
                e.printStackTrace();
                logger.error("關閉文件IOException!");
            }
        }

    }