HttPclient 以post方式发送json

使用HttpClient 以POST的形式发送json字符串 
步骤: 
1.url 、parameters 
2.创建httpClient对象 
3.创建HttpPost对象 
4.为post对象设置参数 
5.将参数以实体的实行放入post对象中 
6.client.execute(post);返回response对象 
7.通过response对象获取响应码， 
8.获得结果实体 

public void HttpClientPostByJson(){
        String url = "http://localhost:8080/../../";
        String param = "{"endTxnDate":"20151114","merchId":"","sendTime":"201510132012123","startTxnDate":"20151111"}";
                //创建client和post对象
        HttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost(url);
        //json形式
        post.addHeader("content-type", "application/json;charset=utf-8");
        post.addHeader("accept","application/json");
        //json字符串以实体的实行放到post中
        post.setEntity(new StringEntity(param,Charset.forName("utf-8")));
        HttpResponse response = null;
        try {
                        //获得response对象
            response = client.execute(post);
        } catch (Exception e) {
            e.printStackTrace();
        }

        if(HttpStatus.SC_OK!=response.getStatusLine().getStatusCode()){
            System.out.println("请求返回不正确");
        }

        String result="";
        try {
                        //获得字符串形式的结果
            result = EntityUtils.toString(response.getEntity());
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println(result);

    }