保持HttpClient登录状态访问授权api

秒速五厘米 2023-10-10 15:37 64阅读 0赞

## 背景 ##

使用httpClient访问需要登录授权的接口，提示失败没有权限。

## 登录保持HttpClient授权状态 ##

***以下方法只适用于简单的鉴权。复杂鉴权方案不适用***

*  doLogin() 登录  
    使用线程维护变量保存登录后的客户端，在本线程不结束的时候可以一直使用本客户端访问需要授权的API。

public class HttpClientUtil {
        
    
        public static final String LOGIN_URL = "https://xxx/login";
    	
    	// 在一个线程中维护同一个httpClient客户端
    	private static final ThreadLocal<CloseableHttpClient> threadLocal = new ThreadLocal<>();
    
    
        public static JSONObject doLogin() throws IOException {
        
            CloseableHttpClient httpClient = threadLocal.get();
            Map<String, String> loginParam = new HashMap<>();
            loginParam.put("username", "用户名");
            loginParam.put("password", "密码");
    
            if (httpClient == null) {
        
                httpClient = HttpClients.createDefault();
                String rsp = doPost(httpClient, LOGIN_URL, loginParam, null);
                threadLocal.set(httpClient);
                return JSONObject.parseObject(rsp);
            } else {
        
                String rsp = doPost(httpClient, LOGIN_URL, loginParam, null);
                return JSONObject.parseObject(rsp);
            }
        }
    	
    	// 不贴具体访问api的接口了：在同一个访问线程中，取到登录后存起来的同一个 http访问客户端，使用这个客户端可以访问登陆后可已访问的API（复杂鉴权的除外）；
    	// 在线程结束后，httpclient失效，下次访问需要重新授权；
        public static String otherAuthApi() {
        
            CloseableHttpClient httpClient = threadLocal.get();
            // TODO: 执行其他需要授权的 POST GET请求
            return "result";
        }
    
        public static String doPost(CloseableHttpClient client, String url, Map<String, String> parameters, Map<String, String> headerMap) throws IOException {
        
            String result = null;
            HttpPost httpPost = new HttpPost(url);
            if ((parameters != null) && (!(parameters.isEmpty()))) {
        
                List<NameValuePair> nameValuePairs = new ArrayList<>();
                Set<Entry<String, String>> entrySet = parameters.entrySet();
                for (Entry<String, String> item : entrySet) {
        
                    nameValuePairs.add(new BasicNameValuePair(item.getKey(), item.getValue()));
                }
                HttpEntity reqEntity = new UrlEncodedFormEntity(nameValuePairs, Consts.UTF_8);
                httpPost.setEntity(reqEntity);
            }
            // 设置请求头
            if (headerMap != null && !headerMap.isEmpty()) {
        
                Set<Entry<String, String>> entrySet = headerMap.entrySet();
                for (Entry<String, String> item : entrySet) {
        
                    httpPost.addHeader(item.getKey(), item.getValue());
                }
            }
            HttpResponse response = client.execute(httpPost);
            if (response != null) {
        
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
        
                    result = EntityUtils.toString(resEntity, "utf-8");
                }
            }
    
            client.close();
    
            return result;
        }
    
        private static String doGet(CloseableHttpClient client, String url, Map<String, String> parameters, Map<String, String> headerMap) throws IOException, URISyntaxException {
        
            String result = null;
            HttpGet httpGet = new HttpGet(url);
            // 设置请求参数
            if ((parameters != null) && (!(parameters.isEmpty()))) {
        
                URIBuilder uriBuilder = new URIBuilder(url);
                List<NameValuePair> nameValuePairs = new ArrayList<>();
                Set<Entry<String, String>> entrySet = parameters.entrySet();
                for (Entry<String, String> item : entrySet) {
        
                    nameValuePairs.add(new BasicNameValuePair(item.getKey(), item.getValue()));
                }
                uriBuilder.setCharset(StandardCharsets.UTF_8);
                uriBuilder.setParameters(nameValuePairs);
            }
    
            // 设置请求头
            if (headerMap != null && !headerMap.isEmpty()) {
        
                Set<Entry<String, String>> entrySet = headerMap.entrySet();
                for (Entry<String, String> item : entrySet) {
        
                    httpGet.addHeader(item.getKey(), item.getValue());
                }
            }
            HttpResponse response = client.execute(httpGet);
            if (response != null) {
        
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
        
                    result = EntityUtils.toString(resEntity, "utf-8");
                }
            }
            client.close();
            return result;
        }
    
    
    }

*  维持登录后的Cookie

Map<String, String> headersMap = new HashMap<>();
            headersMap.put("cookie", "登录后生成的cookie");
            // 登录后生成的cookie记录下来，就不需要每次重新登录
            // 1. 创建HttpClient客户端：client
            // 2. 将headersMap设置到client
            // 3. 访问API
            doPost(client, ... headersMap)

## 参考链接 ##

*  [HTTP连接如何保持登录状态？OkHttp或者HttpClient][HTTP_OkHttp_HttpClient]

[HTTP_OkHttp_HttpClient]: https://www.cnblogs.com/ivy-xu/p/12873549.html