Java通过httppost交互数据

Java通过httppost交互数据：服务端进行数据交互的时候，通常会通过代码进行http跨系统请求，通常使用post或get方式。在post方式的时候，我们可以使用HttpClient也可以自己实现方法：

public static String sendPost(String url, String param) {
    PrintWriter out = null;
    BufferedReader in = null;
    String result = "";
    try {
        URL realUrl = new URL(url);
        URLConnection conn = realUrl.openConnection();
        conn.setRequestProperty("accept", "*/*");
        conn.setRequestProperty("connection", "Keep-Alive");
        conn.setRequestProperty("user-agent",
                "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
        conn.setRequestProperty("content-type", "text/html");
        // 发送POST请求必须设置如下两行
        conn.setDoOutput(true);
        conn.setDoInput(true);
        out = new PrintWriter(conn.getOutputStream());
        out.print(param);
        out.flush();
        // 定义BufferedReader输入流来读取URL的响应
        in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = in.readLine()) != null) {
            result += line;
        }
    } catch (Exception e) {
        System.out.println("发送 POST 请求出现异常！"+e);
        log.error(e);
    } finally{
        try{
            if(out!=null){
                out.close();
            }
            if(in!=null){
                in.close();
            }
        } catch(IOException ex){
            log.error(ex);
        }
    }
    return result;
} 

比如我们通过代码传递json数据：

String serviceViewTime = HttpUtils.sendPost(dcmsUrl + "dcms/audiencerating/queryServiceViewTime.action",
"{\"areacode\":" + areacode + ", \"wbegintime\":\"" + wbegintime + "\", \"wendtime\":\"" + wendtime +"\"}");

log.info("1111serviceViewTime=" + serviceViewTime);

接收端Action，我们可以通过读取request请求体的信息，进而得到数据：

public void queryServiceViewTime() {
    PrintWriter out = null;
    try {
        out = response.getWriter();
        StringBuffer sb = new StringBuffer();
        InputStream is = request.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        String str = "";
        while ((str = br.readLine()) != null) {
            sb.append(str);
        }
        MinParam param = new MinParam();
        if(StringUtils.isNotEmpty(sb.toString())) {
            MinParam param1 = JsonUtil.toObjectByJson(sb.toString(), MinParam.class);
            if(null != param1) {
                param = param1;
            }
        } else {
            out.print("");
            return;
        }
        List list = audienceRatingService.getOneDayServiceWatchTime(param.getAreacode() == null ? null: param.getAreacode()+"", param.getWbegintime(),
                param.getWendtime());
        out.print(JsonUtil.toJsonString(list));
    } catch (Exception e) {
        out.print("");
        log.error(e);
    }
}

也就是从流中读取数据，并转化成我们需要的对象即可。