Android 总结6：Session和Cookie的小结

1. Session 是保存在服务端，用于标识用户

2. Cookie 是保存在客户端的，浏览器端

3. Cookie使用HTTP Header 传递数据
   Cookie机制定义了两种Header ：Set-Cookie Header 和Cookie Header

Set-Cookie Header 包含于Web服务器的响应头（Response Header）中
Cookie Header 包含在浏览器客户端请求头（Reguest Header）中

4. 绝大部分情况都是用 Cookie 来实现Session跟踪的 ，在 Cookie 里面记录了一个Session ID

5. Session ID 是一种机制，不同的环境有不同的叫法 比如： java web 是 JSESSIONID

6. 常用：(1)自行获取 sessionId
   HttpClient请求使用(一个例子)

  classicApplication.getHeadersMap().put("JSESSIONID",sessionId);//01866fbe-725c-482b-aca1-dcd32a6dcfe2

HttpURLConnection请求使用

  classicApplication.getHeadersMap().put("Cookie","SESSION="sessionId);//01866fbe-725c-482b-aca1-dcd32a6dcfe2
//参数名可以从取的sessionid中huode
    String responseCookie = connection.getHeaderField("Set-Cookie");//取到所用的Cookie
                if (responseCookie != null) {
                    //取出sessionId
                    String sessionId = responseCookie.substring(0, responseCookie.indexOf(";"));
                    Log.i(TAG, " responseCookie sessionId:" +sessionId);//responseCookie sessionId:SESSION=2aeeaf6b-f9f7-4106-a2ac-aa7038de388b
                }

okhttp等使用

classicApplication.getHeadersMap().put("Cookie","SESSION="+sessionId);//01866fbe-725c-482b-aca1-dcd32a6dcfe2

(2)利用okhttp自带的方式1

   // .addInterceptor(httpCookiesInterceptor)

public class HttpCookiesInterceptor implements Interceptor {
   private List<String> mCookies=new ArrayList<>();
   {
       Log.i("zfq", "HttpCookiesInterceptor instance initializer: ");
   }
   @Override
   public Response intercept(Chain chain) throws IOException {
       //请求  设置Cookie
       Request request = chain.request();
       Request.Builder newBuilder = request.newBuilder();
       //newBuilder.addHeader("Accept", "Application/JSON");
       if (mCookies != null) {
           for (String cookie : mCookies) {//1条
               newBuilder.addHeader("Cookie", cookie);
               Log.i("zfq", "HttpCookiesInterceptor intercept: Cookie:"+cookie);
           }
       }
       Request newRequest = newBuilder.build();

       //响应
       Response response = chain.proceed(newRequest);
       if (response.headers("Set-Cookie") != null){
           for (String header : response.headers("Set-Cookie")) {//1条
               mCookies.add(header);
               Log.i("zfq", "HttpCookiesInterceptor intercept: Set-Cookie:"+header);
           }
       }
       return response;
   }
}

(2)利用okhttp自带的方式2

   //.cookieJar(myCookieJar) //okhttp3

//OkHttp的是否单例影响着CookieJar的工作
     CookieJar myCookieJar=new CookieJar() {
         //private final
         Map<String, List<Cookie>> cookiesMap= new HashMap<>();
         {
             Log.i("zfq", "OkHttpManager instance initializer: ");
         }
         @Override
         public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
             Log.i("zfq", "OkHttpManager saveFromResponse "+url);
             cookiesMap.put(url.host(), cookies);
             if (EmptyTool.isNotEmpty(cookies)) {
                 for (Cookie cookie : cookies) {
                     Log.i("zfq", "OkHttpManager saveFromResponse: " + cookie.value());
                 }
             }
         }

         @Override
         public List<Cookie> loadForRequest(HttpUrl url) {
             Log.i("zfq", "OkHttpManager loadForRequest "+url);
             List<Cookie> cookies = cookiesMap.get(url.host());
             if (EmptyTool.isNotEmpty(cookies)) {
                 for (Cookie cookie : cookies) {
                     Log.i("zfq", "OkHttpManager saveFromResponse: " + cookie.value());
                 }
              }
            return cookies != null ? cookies : new ArrayList<Cookie>();
         }
     };