说明
最近封装一个SDK时，遇到一个需求就是登录成功之后，APP需要持久保存Cookie，当APP退出再进入时需要从本地读取Cookie值，类似于浏览器，一个网站登录成功之后，关闭浏览器再打开，还能继续访问这个网站网页。
Cookie
图片来源：https://www.cnblogs.com/zhuanzhuanfe/p/8010854.html
分析
首先我们清除谷歌浏览器里面缓存的Cookie，当首次访问百度https://www.baidu.com/，请求体中还没有携带Cookie，响应体中会出现Set-Cookie字段，要求浏览器保存Cookie，当第二次请求时会携带这个Cookie信息。
请求头（第一次请求）：
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Connection: keep-alive
Host: www.baidu.com
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3472.3 Safari/537.36
响应头：
Bdpagetype: 1
Bdqid: 0xe1a8fd3600011fd8
Cache-Control: private
Connection: Keep-Alive
Content-Encoding: gzip
Content-Type: text/html
Cxy_all: baidu+c1a146ec227bccffbb8afe4da97bdf3e
Date: Sat, 06 Apr 2019 09:48:35 GMT
Expires: Sat, 06 Apr 2019 09:47:45 GMT
P3p: CP=" OTI DSP COR IVA OUR IND COM "
Server: BWS/1.1
Set-Cookie: PSTM=1554544115; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BAIDUID=F7EBDE8F1230A7DDF1DD141A458BD04B:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BIDUPSID=F7EBDE8F1230A7DDF1DD141A458BD04B; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: delPer=0; path=/; domain=.baidu.com
Set-Cookie: BDSVRTM=0; path=/
Set-Cookie: BD_HOME=0; path=/
Set-Cookie: H_PS_PSSID=1439_28794_21081_28774_28721_28558_28585_26350_28604_28625_22159; path=/; domain=.baidu.com
Strict-Transport-Security: max-age=172800
Transfer-Encoding: chunked
Vary: Accept-Encoding
X-Ua-Compatible: IE=Edge,chrome=1
请求头（第二次请求）：
里面携带Cookie信息
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Cache-Control: max-age=0
Connection: keep-alive
Cookie: BAIDUID=F7EBDE8F1230A7DDF1DD141A458BD04B:FG=1; BIDUPSID=F7EBDE8F1230A7DDF1DD141A458BD04B; PSTM=1554544115; delPer=0; BD_HOME=0; H_PS_PSSID=1439_28794_21081_28774_28721_28558_28585_26350_28604_28625_22159; BD_UPN=12314353
Host: www.baidu.com
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3472.3 Safari/537.36
现象
使用的是鸿洋的 okhttputils网络框架，PersistentCookieStore其中存在一个bug；github上也有类似的问题https://github.com/hongyangAndroid/okhttputils/pull/140
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.connectTimeout(10000L, TimeUnit.MILLISECONDS)
.readTimeout(10000L, TimeUnit.MILLISECONDS)
.cookieJar(new CookieJarImpl(new PersistentCookieStore(this)))
// .cookieJar(new CookieJarImpl(new MemoryCookieStore()))
.addInterceptor(new LoggerInterceptor("TAG"))
.build();
OkHttpUtils.initClient(okHttpClient);
String top250 = "http://api.douban.com/v2/movie/top250";
// 配置基本网络请求
OkHttpUtils.get().url(top250)
.build()
.execute(new StringCallback() {
@Override
public void onError(Call call, Exception e, int id) {
Log.d(TAG, " 失败：" + e.toString());
}
@Override
public void onResponse(String response, int id) {
Log.d(TAG, " 成功：" + response);
}
});
当设置内存保存Cookie时（MemoryCookieStore），第二次访问携带上Cookie，但是退出APP之后就丢失了。
当设置永久保存Cookie时（PersistentCookieStore），第二次访问还是没有携带上Cookie，
image.png
PersistentCookieStore代码实现
persistent值
从源码上可以看出，当请求头中存在expires和max-age时，返回为True，这个时候PersistentCookieStore是不对Cookie进行磁盘、内存存储的，这里只是设置一个Cookie的有效期，此时Cookie值并没有过期。
维持持久化Cookie，推荐使用持久化cookie框架，PersistentCookieJar，
ClearableCookieJar cookieJar =
new PersistentCookieJar(new SetCookieCache(), new SharedPrefsCookiePersistor(this));
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.connectTimeout(10000L, TimeUnit.MILLISECONDS)
.readTimeout(10000L, TimeUnit.MILLISECONDS)
.cookieJar(cookieJar)
// .cookieJar(new CookieJarImpl(new PersistentCookieStore(this)))
// .cookieJar(new CookieJarImpl(new MemoryCookieStore()))
.addInterceptor(new LoggerInterceptor("TAG"))
.build();
OkHttpUtils.initClient(okHttpClient);
Cookie未保存
Cookie过滤条件
persistent
Cookie判断
从源码上可以看出，当请求头中不存在expires和max-age时，返回为False，这个时候PersistentCookieJar是不对Cookie进行磁盘存储的。
另外一种情况
okttp3访问IP地址Cookie丢失的现象，这里使用百度的IP地址：http://220.181.112.244:80/，
//这里使用百度IP地址
String baidu = "http://220.181.112.244:80/";
// 配置基本网络请求
OkHttpUtils.get().url(baidu)
.build()
.execute(new StringCallback() {
@Override
public void onError(Call call, Exception e, int id) {
Log.d(TAG, " 失败：" + e.toString());
}
@Override
public void onResponse(String response, int id) {
Log.d(TAG, " 成功：" + response);
}
});
丢失Cookie情况
查看OkHttp-3.3.1底层Cookie实现，可以看到这一部分代码：
...
} else if (attributeName.equalsIgnoreCase("domain")) {
try {
domain = parseDomain(attributeValue);
hostOnly = false;
} catch (IllegalArgumentException e) {
// Ignore this attribute, it isn't recognizable as a domain.
}
}
...
// If the domain is present, it must domain match. Otherwise we have a host-only cookie.
if (domain == null) {
domain = url.host();
} else if (!domainMatch(url, domain)) {
return null; // No domain match? This is either incompetence or malice!
}
...
for (int i = 0, size = cookieStrings.size(); i < size; i++) {
Cookie cookie = Cookie.parse(url, cookieStrings.get(i));
if (cookie == null) continue;
if (cookies == null) cookies = new ArrayList<>();
cookies.add(cookie);
}
当请求头中存在domain时，这个时候主地址为ip与domian不等，Cookie解析失败为null，导致保存Cookie失败，这个浏览器也是存在问题的，这个得后台注意格式。
浏览器情况
代码实现
第一种实现方式（拦截器实现）
这里为了安全可以对Cookie进行加密存储，可以使用这个SharedPreferences加密库，https://github.com/iamMehedi/Secured-Preference-Store
mSharedPreferences = getSharedPreferences("Cookie_Pre", Context.MODE_PRIVATE);
cookies = new HashMap<>();
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.connectTimeout(10000L, TimeUnit.MILLISECONDS)
.readTimeout(10000L, TimeUnit.MILLISECONDS)
//网络拦截器
.addInterceptor(new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
//获取请求链接
Request originalRequest = chain.request();
//获取url的主机地址
String hostString = originalRequest.url().host();
if (!cookies.containsKey(hostString)) {
//获取磁盘里面的spCookie字符串
String spCookie = mSharedPreferences.getString(hostString, "");
if (!TextUtils.isEmpty(spCookie)) {
//获取spCookie解密放到内存中
cookies.put(hostString, spCookie);
}
}
//获取内存中的Cookie
String memoryCookie = cookies.get(hostString);
//拦截网络请求数据
Request request = originalRequest.newBuilder()
//设置请求头Cookie值
.addHeader("Cookie", memoryCookie == null ? "" : memoryCookie)
.build();
//拦截返回数据
Response originalResponse = chain.proceed(request);
//判断请求头里面是否有Set-Cookie值,更新Cookie
if (!originalResponse.headers("Set-Cookie").isEmpty()) {
//字符串集
StringBuilder stringBuilder = new StringBuilder();
for (String header : originalResponse.headers("Set-Cookie")) {
stringBuilder.append(header);
stringBuilder.append(";");
}
//拼接Cookie成字符串
String cookie = stringBuilder.toString();
//更新内存中Cookies值
cookies.put(hostString, cookie);
//存储到本地磁盘中
SharedPreferences.Editor editor = mSharedPreferences.edit();
//存储cookie（为了安全这里可以加密存储）
editor.putString(hostString, cookie);
editor.apply();
Log.e("Set-Cookie", "cookies: " + cookie + " host: " + hostString);
}
return originalResponse;
}
})
.addInterceptor(new LoggerInterceptor("TAG"))
.build();
OkHttpUtils.initClient(okHttpClient);
第二种实现方式（继承CookieJar实现）
这里可以参考OKGO里面实现的库，Cookie，实现
CookieJarImpl继承CookieJar和SPCookieStore。
public class SPCookieStore implements CookieStore {
private static final String COOKIE_PREFS = "okhttp_cookie"; //cookie使用prefs保存
private static final String COOKIE_NAME_PREFIX = "cookie_"; //cookie持久化的统一前缀
private final Map<String, ConcurrentHashMap<String, Cookie>> cookies;
private final SharedPreferences cookiePrefs;
public SPCookieStore(Context context) {
cookiePrefs = context.getSharedPreferences(COOKIE_PREFS, Context.MODE_PRIVATE);
cookies = new HashMap<>();
//将持久化的cookies缓存到内存中,数据结构为 Map<Url.host, Map<CookieToken, Cookie>>
Map<String, ?> prefsMap = cookiePrefs.getAll();
for (Map.Entry<String, ?> entry : prefsMap.entrySet()) {
if ((entry.getValue()) != null && !entry.getKey().startsWith(COOKIE_NAME_PREFIX)) {
//获取url对应的所有cookie的key,用","分割
String[] cookieNames = TextUtils.split((String) entry.getValue(), ",");
for (String name : cookieNames) {
//根据对应cookie的Key,从xml中获取cookie的真实值
String encodedCookie = cookiePrefs.getString(COOKIE_NAME_PREFIX + name, null);
if (encodedCookie != null) {
Cookie decodedCookie = SerializableCookie.decodeCookie(encodedCookie);
if (decodedCookie != null) {
if (!cookies.containsKey(entry.getKey())) {
cookies.put(entry.getKey(), new ConcurrentHashMap<String, Cookie>());
}
cookies.get(entry.getKey()).put(name, decodedCookie);
}
}
}
}
}
}
private String getCookieToken(Cookie cookie) {
return cookie.name() + "@" + cookie.domain();
}
/** 当前cookie是否过期 */
private static boolean isCookieExpired(Cookie cookie) {
return cookie.expiresAt() < System.currentTimeMillis();
}
/** 将url的所有Cookie保存在本地 */
@Override
public synchronized void saveCookie(HttpUrl url, List<Cookie> urlCookies) {
for (Cookie cookie : urlCookies) {
saveCookie(url, cookie);
}
}
@Override
public synchronized void saveCookie(HttpUrl url, Cookie cookie) {
if (!cookies.containsKey(url.host())) {
cookies.put(url.host(), new ConcurrentHashMap<String, Cookie>());
}
//当前cookie是否过期
if (isCookieExpired(cookie)) {
removeCookie(url, cookie);
} else {
saveCookie(url, cookie, getCookieToken(cookie));
}
}
/** 保存cookie，并将cookies持久化到本地 */
private void saveCookie(HttpUrl url, Cookie cookie, String cookieToken) {
//内存缓存
cookies.get(url.host()).put(cookieToken, cookie);
//文件缓存
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.putString(url.host(), TextUtils.join(",", cookies.get(url.host()).keySet()));
prefsWriter.putString(COOKIE_NAME_PREFIX + cookieToken, SerializableCookie.encodeCookie(url.host(), cookie));
prefsWriter.apply();
}
/** 根据当前url获取所有需要的cookie,只返回没有过期的cookie */
@Override
public synchronized List<Cookie> loadCookie(HttpUrl url) {
List<Cookie> ret = new ArrayList<>();
if (!cookies.containsKey(url.host())) return ret;
Collection<Cookie> urlCookies = cookies.get(url.host()).values();
for (Cookie cookie : urlCookies) {
if (isCookieExpired(cookie)) {
removeCookie(url, cookie);
} else {
ret.add(cookie);
}
}
return ret;
}
/** 根据url移除当前的cookie */
@Override
public synchronized boolean removeCookie(HttpUrl url, Cookie cookie) {
if (!cookies.containsKey(url.host())) return false;
String cookieToken = getCookieToken(cookie);
if (!cookies.get(url.host()).containsKey(cookieToken)) return false;
//内存移除
cookies.get(url.host()).remove(cookieToken);
//文件移除
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
if (cookiePrefs.contains(COOKIE_NAME_PREFIX + cookieToken)) {
prefsWriter.remove(COOKIE_NAME_PREFIX + cookieToken);
}
prefsWriter.putString(url.host(), TextUtils.join(",", cookies.get(url.host()).keySet()));
prefsWriter.apply();
return true;
}
@Override
public synchronized boolean removeCookie(HttpUrl url) {
if (!cookies.containsKey(url.host())) return false;
//内存移除
ConcurrentHashMap<String, Cookie> urlCookie = cookies.remove(url.host());
//文件移除
Set<String> cookieTokens = urlCookie.keySet();
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
for (String cookieToken : cookieTokens) {
if (cookiePrefs.contains(COOKIE_NAME_PREFIX + cookieToken)) {
prefsWriter.remove(COOKIE_NAME_PREFIX + cookieToken);
}
}
prefsWriter.remove(url.host());
prefsWriter.apply();
return true;
}
@Override
public synchronized boolean removeAllCookie() {
//内存移除
cookies.clear();
//文件移除
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.clear();
prefsWriter.apply();
return true;
}
/** 获取所有的cookie */
@Override
public synchronized List<Cookie> getAllCookie() {
List<Cookie> ret = new ArrayList<>();
for (String key : cookies.keySet()) {
ret.addAll(cookies.get(key).values());
}
return ret;
}
@Override
public synchronized List<Cookie> getCookie(HttpUrl url) {
List<Cookie> ret = new ArrayList<>();
Map<String, Cookie> mapCookie = cookies.get(url.host());
if (mapCookie != null) ret.addAll(mapCookie.values());
return ret;
}
}
//当前cookie是否过期
if (isCookieExpired(cookie)) {
removeCookie(url, cookie);
} else {
saveCookie(url, cookie, getCookieToken(cookie));
}
/** 当前cookie是否过期 */
private static boolean isCookieExpired(Cookie cookie) {
return cookie.expiresAt() < System.currentTimeMillis();
}
【总结】这里保存持久化Cookie的关键看expiresAt与当前时间戳相比是否为过期，而不是看响应头里是否存在expires和max-age字段。
使用与之前类似:
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.connectTimeout(10000L, TimeUnit.MILLISECONDS)
.readTimeout(10000L, TimeUnit.MILLISECONDS)
.cookieJar(new CookieJarImpl(new SPCookieStore()))
.addInterceptor(new LoggerInterceptor("TAG"))
.build();
OkHttpUtils.initClient(okHttpClient);
总结
后台对Cookie返回格式还是要规范一点，否则Cookie持久化保存会出现莫名其妙的错误。
