JAVA下载TXT文件到本地，这一个方法完全能够解决

 public String selectBmb() throws Exception {

  String src = SystemConfig.getUploadPath() + "text.txt";

  String xsxm = this.formBean.getString("PHONE");

  String cxmm = this.formBean.getString("cxmm");

  java.io.File f = new java.io.File(src);

  BufferedWriter bw = null;

  bw = new BufferedWriter(new FileWriter(f));

  // 写入文件

  bw.write(xsxm + "\r\n" + cxmm);

  bw.flush();

  bw.close();

  // 下载打开文件

  String filePath = src;

  String fileName = "保存密码";

  //boolean isInline = false;

  out.clear();

  this.pageWrapper.response.reset();

  fileName = "保存密码" + ".txt";

  java.io.File f1 = new java.io.File(filePath);

  this.pageWrapper.response.setContentType("application/x-download");

  this.pageWrapper.response.setHeader(

    "Content-Disposition",

    "attachment;filename="

      + java.net.URLEncoder.encode(fileName, "UTF8"));

  this.pageWrapper.response.setContentLength((int) f1.length()); // ?

                  // 设置下载内容大小?

  if (fileName != null && filePath != null) {

   try {

    if (f.exists() && f.canRead()) {

     //String mimetype = null;

     byte[] buffer = new byte[4096]; // ? 缓冲区

     BufferedOutputStream output = null;

     BufferedInputStream input = null;

     try {

      output = new BufferedOutputStream(

        this.pageWrapper.response.getOutputStream());

      input = new BufferedInputStream(new FileInputStream(f));

      int n = (-1);

      while ((n = input.read(buffer, 0, 4096)) > -1) {

       output.write(buffer, 0, n);

      }

      this.pageWrapper.response.flushBuffer();

     } catch (Exception e) {

     } // ? 用户可能取消了下载

     finally {

      if (input != null)

       input.close();

      if (output != null)

       output.close();

     }

    }

    

   } catch (Exception ex) {

    ex.printStackTrace();

   }

  }

  return null;

 }