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);
		
	}