此處發請求的是用httpclient4,請自己下載所需要的jar包。

發post請求，并得到數據。

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String url = "http://localhost:8080/lee";url = url+ "/query/action/export.action";String exportFilePath = "lee"+".csv.";final HttpClient httpClient = new DefaultHttpClient();final HttpPost post = new HttpPost(url);List<NameValuePair> params = new ArrayList<NameValuePair>(); params.add(new BasicNameValuePair("leeSmart", leeSmart));//發post請求的參數post.setEntity(new UrlEncodedFormEntity(params,HTTP.UTF_8));final HttpResponse response = httpClient.execute(post);//得到返回的responsefinal int code = response.getStatusLine().getStatusCode();final HttpEntity entity = response.getEntity();//得到entityif (entity != null && code < 400) {InputStream inputStream = entity.getContent();//得到從服務器端返回的數據流long length = entity.getContentLength();if(length<=0) return;int len = (int)length;byte[] b = new byte[len];int readCount = 0;//建議用以下方式讀inputStream為b賦值while (readCount < len) { readCount += inputStream.read(b, readCount, len - readCount); } //在客戶端生成文件。更高效的做法是，在服務器端傳過來一個壓縮后的btye[]，然后在客戶端解壓，減少傳輸數據。try {FileOutputStream fo1 = null;fo1 = new FileOutputStream(exportFilePath);fo1.write(b);}fo1.close();} catch (Exception e2) {e2.printStackTrace();}}

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在action中接請求的方法export()，并返回數據流

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try {request.setCharacterEncoding("UTF-8");} catch (UnsupportedEncodingException e1) {e1.printStackTrace();}response.setCharacterEncoding("UTF-8");String leeSmart = request.getParameter("leeSmart");//前臺傳過來的post參數byte[] b = null;try{List ret = serivce.query("select * from dual");//得到查詢結果集//將ret放到sb中StringBuilder sb = new StringBuilder();//.......對結果集進行處理，并轉成字節數組 b = sb.toString().getByte();}catch(Exception e){e.printStackTrace();}//如果方便，可以把b字節數組壓縮一下，這樣傳的數據會比較小一些。//將字節數組放到response中，并返回到客戶端。try {response.reset();// 設置response的Headerresponse.addHeader("Content-Disposition", "attachment;filename=" + new String("random".getBytes("UTF-8"),"ISO-8859-1"));response.addHeader("Content-Length", "" + b.length);OutputStream toClient = new BufferedOutputStream(response.getOutputStream());response.setContentType("application/octet-stream");toClient.write(b);toClient.flush();toClient.close();} catch (Exception e) {e.printStackTrace();}finally{}

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轉載于:https://www.cnblogs.com/suncoolcat/p/3295154.html

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