httpClient请求 | 易学教程

1. 将 pojo 转换成json ，使用 HttpClient 发送请求

1. 1 在 OrderServiceImpl 中

@Override
	public String createOrder(Order order) {
		//调用创建订单服务之前补全用户信息。
		//从cookie中后取TT_TOKEN的内容，根据token调用sso系统的服务根据token换取用户信息。
		
		//调用taotao-order的服务提交订单。
		String json = HttpClientUtil.doPostJson(ORDER_BASE_URL + ORDER_CREATE_URL, JsonUtils.objectToJson(order));
		//把json转换成taotaoResult
		TaotaoResult taotaoResult = TaotaoResult.format(json);
		if (taotaoResult.getStatus() == 200) {
			Object orderId = taotaoResult.getData();
			return orderId.toString();
		}
		return "";
	}

1.2 在 HttpClientUtil 中

public static String doPostJson(String url, String json) {
		// 创建Httpclient对象
		CloseableHttpClient httpClient = HttpClients.createDefault();
		CloseableHttpResponse response = null;
		String resultString = "";
		try {
			// 创建Http Post请求
			HttpPost httpPost = new HttpPost(url);
			// 创建请求内容
			StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
			httpPost.setEntity(entity);
			// 执行http请求
			response = httpClient.execute(httpPost);
			resultString = EntityUtils.toString(response.getEntity(), "utf-8");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				response.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		return resultString;
	}

2。将所有参数添加在Map<String,String>中，使用HttpClient发送请求

根据参数查询分页

@Override
	public SearchResult search(String queryString, int page) {
		// 调用taotao-search的服务
		//查询参数
		Map<String, String> param = new HashMap<>();
		param.put("q", queryString);
		param.put("page", page + "");
		try {
			//调用服务
			String json = HttpClientUtil.doGet(SEARCH_BASE_URL, param);
			//把字符串转换成java对象
			TaotaoResult taotaoResult = TaotaoResult.formatToPojo(json, SearchResult.class);
			if (taotaoResult.getStatus() == 200) {
				SearchResult result = (SearchResult) taotaoResult.getData();
				return result;
			}
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

HttpClientUtil 中

public static String doGet(String url, Map<String, String> param) {

		// 创建Httpclient对象
		CloseableHttpClient httpclient = HttpClients.createDefault();

		String resultString = "";
		CloseableHttpResponse response = null;
		try {
			// 创建uri
			URIBuilder builder = new URIBuilder(url);
			if (param != null) {
				for (String key : param.keySet()) {
					builder.addParameter(key, param.get(key));
				}
			}
			URI uri = builder.build();

			// 创建http GET请求
			HttpGet httpGet = new HttpGet(uri);

			// 执行请求
			response = httpclient.execute(httpGet);
			// 判断返回状态是否为200
			if (response.getStatusLine().getStatusCode() == 200) {
				resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (response != null) {
					response.close();
				}
				httpclient.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return resultString;
	}

其中 SEARCH_BASE_URL 配置在 resource.properties中

SEARCH_BASE_URL=http://192.168.25.136:8081/search/query

/search/query 接口

@RequestMapping(value="/query", method=RequestMethod.GET)
	@ResponseBody
	public TaotaoResult search(@RequestParam("q")String queryString, 
			@RequestParam(defaultValue="1")Integer page, 
			@RequestParam(defaultValue="60")Integer rows) {
		//查询条件不能为空
		if (StringUtils.isBlank(queryString)) {
			return TaotaoResult.build(400, "查询条件不能为空");
		}
		SearchResult searchResult = null;
		try {
			queryString = new String(queryString.getBytes("iso8859-1"), "utf-8");
			searchResult = searchService.search(queryString, page, rows);
		} catch (Exception e) {
			e.printStackTrace();
			return TaotaoResult.build(500, ExceptionUtil.getStackTrace(e));
		}
		return TaotaoResult.ok(searchResult);
		
	}

总结：发布的接口中参数是Integer类型，使用HttpCliet请求时可以使用 String 类型数据发送

来源：oschina

链接：https://my.oschina.net/u/3631797/blog/3157904

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httpclient