httpClient和RestTemplate的使用

1、httpClient的使用

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.3.5</version>
</dependency>

// 第一步：创建一个httpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();

// 第二步：创建一个HttpPost对象。需要指定一个url
// HttpPost post = new HttpPost("http://47.244.48.xxx/xxx/xxx/");
HttpPost post = new HttpPost("http://127.0.0.1:8080/xxx/xxx/");

// 携带cookie
String sessionId = "PHPSESSID=KSoxfJlB20JJ0...";
BasicHeader header = new BasicHeader("Cookie", sessionId);
post.setHeader(header);

// 第三步：创建一个list模拟表单，list中每个元素是一个NameValuePair对象
List<NameValuePair> formList = new ArrayList<>();
formList.add(new BasicNameValuePair("xxx", "xxx"));
formList.add(new BasicNameValuePair("xxx", "xxx"));

// 第四步：需要把表单数据包装到Entity对象中: StringEntity
StringEntity entity = new UrlEncodedFormEntity(formList, "utf-8");
post.setEntity(entity);

// 第五步：执行请求。
CloseableHttpResponse response = httpClient.execute(post);

// 第六步：接收返回结果
HttpEntity httpEntity = response.getEntity();
String result = EntityUtils.toString(httpEntity);
System.out.println(result);

// 第七步：关闭流。
response.close();
httpClient.close();

2、RestTemplate的使用：get请求带Cookie

String url = Config.XXX_BASE_URL + "/userlevel?inviterId=" + invit1;
String restInfo = MessageFormat.format("url:{0}, inviterId:{1}", url, invit1);
UtilFunctions.log.info("UserController#register call rest api info, " + restInfo);

HttpHeaders requestHeaders = new HttpHeaders();
List<String> cookieList = UtilFunctions.getCookieList(request);
requestHeaders.put("Cookie", cookieList);
HttpEntity<String> requestEntity = new HttpEntity<String>(null, requestHeaders);
restTemplate.exchange(url, HttpMethod.GET, requestEntity, JSONObject.class).getBody();

　　

　　UtilFunctions类的getCookieList()方法

public static List<String> getCookieList(HttpServletRequest request) {
    List<String> cookieList = new ArrayList<>();

    Cookie[] cookies = request.getCookies();
    if (cookies == null || cookies.length == 0) {
        return cookieList;
    }

    for (Cookie cookie : cookies) {
        cookieList.add(cookie.getName() + "=" + cookie.getValue());
    }

    return cookieList;
}

参考资料：

　　1）Springboot — 用更优雅的方式发HTTP请求(RestTemplate详解)