OKHTTP3自定义CookieJar和及Cookie持久化
一、简介
Cookie会包含如下信息：name expires domain path secure；
name:cookie 的名字；
expires:过期时间。值是一个日期，一个时刻，而不是一个时长。在OkHttp中，你可以使用该字段在端上建立逻辑，也可以忽略该字段依靠server实现过期的逻辑。
domain：cookie的作用域，指定了cookie将要被发送至哪个域中。默认情况下，domain会被设置为创建该cookie的url所在的域名。但在OkHttp中默认是不存在Cookie机制的，因此这一点需要你来亲自实现完善。像百度这样的网站，会有很多name.baidu.com形式的站点，他们的顶级域名是一致的，但二级域名会有很多，比如waimai.baidu.com，bzclk.baidu.com等。domain的匹配通常是从域名的末尾开始匹配，并将命中的cookie作为有效cookie存储。
path:另一个控制cookie的发送时机的选项。类似于domain，path选项要求请求资源URL中必须存在指定的路径，才会发送cookie。通常是将path的值与请求的URL从开头开始逐个字符串比较完成匹配。如：Set-Cookie：name=Ghost;path=/ghost就要求URL的路径以/ghost开头，如/ghost,/ghostinmatrix都是命中的url。
secure：该选项只是一给标记而没有值。只有当一个请求通过SSL或者HTTPS创建的时候，包含secure的cookie才能被发送至服务器。这种cookie内容具有很高价值，如果一纯文本形式传递很有可能被篡改。事实上，机密且敏感的数据是不应该再cookie中存储的，因为cookie整个机制本身就是不安全的。
二、OkHttp的Cookie的说明及调用
OkHttp网络库提供了自定义 CookieJar机制来满足应用对Cookie的各种定制需求。在OkHttp的源码中，明确了两点：
1.不自定义CookieJar时默认没有Cookie， 如下：
/** A cookie jar that never accepts any cookies. */
CookieJar NO_COOKIES = new CookieJar() {
@Override public void saveFromResponse(HttpUrl url, List cookies) {
}
@Override public List loadForRequest(HttpUrl url) {
return Collections.emptyList();
}
};
2. 在设置自定义CookieJar时，需要实现该接口的2个方法：
public class MyCookieJarImpl implements CookieJar {
private final PersistentCookieStore cookieStore = PersistentCookieStore.getInstance();
public MyCookieJarImpl (OkCookieManager cookieManager) {
this.cookieManager = cookieManager;
}
@Override
public void saveFromResponse(HttpUrl url, List cookies) {
//本地可校验cookie，并根据需要存储
if (cookies != null && cookies.size() > 0) {
for (Cookie item : cookies) {
cookieStore.add(url, item);
}
}
}
@Override
public List loadForRequest(HttpUrl url) {
//从本地拿取需要的cookie
return cookieStore.get(url);;
}
}
OkHttp在组装请求过程中，HttpEngine会调用CookieJar的loadForRequest方法，
private Request networkRequest(Request request) throws IOException {
......
List cookies = client.cookieJar().loadForRequest(request.url());
if (!cookies.isEmpty()) {
result.header("Cookie", cookieHeader(cookies));
}
.....
return result.build();
}
其中的client就是 设置了CookieJar的OkHttpClient；
在请求接口的时候，还是在HttpEngine中，使用saveFromResponse方法将来自server的cookie存储到本地：
public void receiveHeaders(Headers headers) throws IOException {
if (client.cookieJar() == CookieJar.NO_COOKIES) return;
/**
*从Header中获取Cookie并解析为对象，如果Cookie存在，则saveFromResponse
*一般app登录的时候headers中会有Cookie，而其他的接口的headers不包含Cookie
*/
List cookies = Cookie.parseAll(userRequest.url(), headers);
if (cookies.isEmpty()) return;
client.cookieJar().saveFromResponse(userRequest.url(), cookies);
}
以上就是CookieJar的设置就调用流程，下面看看怎么将Cookie存储到本地，以下代码都很好理解，都要注释了，我就直接贴代码了，有问题的可以交流下：
public class PersistentCookieStore {
private static final String LOG_TAG = "PersistentCookieStore";
private static final String COOKIE_PREFS = "Cookies_Prefs";
private final Map> cookies;
private final SharedPreferences cookiePrefs;
private static PersistentCookieStore mInstance;
public static PersistentCookieStore getInstance() {
if(mInstance == null) {
mInstance = new PersistentCookieStore(BaseApp.getInstance());
}
return mInstance;
}
private PersistentCookieStore(Context context) {
cookiePrefs = context.getSharedPreferences(COOKIE_PREFS, 0);
cookies = new HashMap<>();
//将持久化的cookies缓存到内存中 即map cookies
Map prefsMap = cookiePrefs.getAll();
for (Map.Entry entry : prefsMap.entrySet()) {
String[] cookieNames = TextUtils.split((String) entry.getValue(), ",");
for (String name : cookieNames) {
String encodedCookie = cookiePrefs.getString(name, null);
if (encodedCookie != null) {
Cookie decodedCookie = decodeCookie(encodedCookie);
if (decodedCookie != null) {
if (!cookies.containsKey(entry.getKey())) {
cookies.put(entry.getKey(), new ConcurrentHashMap());
}
cookies.get(entry.getKey()).put(name, decodedCookie);
}
}
}
}
}
protected String getCookieToken(Cookie cookie) {
return cookie.name() + "@" + cookie.domain();
}
public synchronized void add(HttpUrl url, Cookie cookie) {
String name = getCookieToken(cookie);
//将cookies缓存到内存中 如果缓存过期 就重置此cookie
if (!cookie.persistent() || cookie.expiresAt() > System.currentTimeMillis()) {
if (!cookies.containsKey(url.host())) {
cookies.put(url.host(), new ConcurrentHashMap());
}
cookies.get(url.host()).put(name, cookie);
} else {
if (cookies.containsKey(url.host())) {
cookies.get(url.host()).remove(name);
}
}
//讲cookies持久化到本地
if (cookies.get(url.host()) != null) {
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.putString(url.host(), TextUtils.join(",", cookies.get(url.host()).keySet()));
prefsWriter.putString(name, encodeCookie(new SerializableOkHttpCookies(cookie)));
prefsWriter.apply();
}
}
public List get(HttpUrl url) {
ArrayList ret = new ArrayList<>();
if (cookies.containsKey(url.host()))
ret.addAll(cookies.get(url.host()).values());
return ret;
}
public synchronized boolean removeAll() {
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.clear();
prefsWriter.apply();
cookies.clear();
return true;
}
public synchronized boolean remove(HttpUrl url, Cookie cookie) {
String name = getCookieToken(cookie);
if (cookies.containsKey(url.host()) && cookies.get(url.host()).containsKey(name)) {
cookies.get(url.host()).remove(name);
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
if (cookiePrefs.contains(name)) {
prefsWriter.remove(name);
}
prefsWriter.putString(url.host(), TextUtils.join(",", cookies.get(url.host()).keySet()));
prefsWriter.apply();
return true;
} else {
return false;
}
}
public synchronized List getCookies() {
ArrayList ret = new ArrayList<>();
for (String key : cookies.keySet())
ret.addAll(cookies.get(key).values());
return ret;
}
/**
* cookies 序列化成 string
*
* @param cookie 要序列化的cookie
* @return 序列化之后的string
*/
protected String encodeCookie(SerializableOkHttpCookies cookie) {
if (cookie == null)
return null;
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
ObjectOutputStream outputStream = new ObjectOutputStream(os);
outputStream.writeObject(cookie);
} catch (IOException e) {
l.d(LOG_TAG, "IOException in encodeCookie", e);
return null;
}
return byteArrayToHexString(os.toByteArray());
}
/**
* 将字符串反序列化成cookies
*
* @param cookieString cookies string
* @return cookie object
*/
protected Cookie decodeCookie(String cookieString) {
byte[] bytes = hexStringToByteArray(cookieString);
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes);
Cookie cookie = null;
try {
ObjectInputStream objectInputStream = new ObjectInputStream(byteArrayInputStream);
cookie = ((SerializableOkHttpCookies) objectInputStream.readObject()).getCookies();
} catch (IOException e) {
l.d(LOG_TAG, "IOException in decodeCookie", e);
} catch (ClassNotFoundException e) {
l.d(LOG_TAG, "ClassNotFoundException in decodeCookie", e);
}
return cookie;
}
/**
* 二进制数组转十六进制字符串
*
* @param bytes byte array to be converted
* @return string containing hex values
*/
protected String byteArrayToHexString(byte[] bytes) {
StringBuilder sb = new StringBuilder(bytes.length * 2);
for (byte element : bytes) {
int v = element & 0xff;
if (v < 16) {
sb.append('0');
}
sb.append(Integer.toHexString(v));
}
return sb.toString().toUpperCase(Locale.US);
}
/**
* 十六进制字符串转二进制数组
*
* @param hexString string of hex-encoded values
* @return decoded byte array
*/
protected byte[] hexStringToByteArray(String hexString) {
int len = hexString.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character.digit(hexString.charAt(i + 1), 16));
}
return data;
}
}
Cookie持久化
如果Cookie仅存在于内存中，那么App关闭之后，所有cookie就都消失；而我们期望的是下次打开App的时候依然能够自动登录进入主界面，这就需要我们对Cookie进行文件级别的持久化。但是，okhttp3.Cookie有一个很坑爹的情况：它没有实现Serializable接口，无法序列化。因此，我们只能自己实现序列化:
public class SerializableOkHttpCookies implements Serializable {
private transient final Cookie cookies;
private transient Cookie clientCookies;
public SerializableOkHttpCookies(Cookie cookies) {
this.cookies = cookies;
}
public Cookie getCookies() {
Cookie bestCookies = cookies;
if (clientCookies != null) {
bestCookies = clientCookies;
}
return bestCookies;
}
private void writeObject(ObjectOutputStream out) throws IOException {
out.writeObject(cookies.name());
out.writeObject(cookies.value());
out.writeLong(cookies.expiresAt());
out.writeObject(cookies.domain());
out.writeObject(cookies.path());
out.writeBoolean(cookies.secure());
out.writeBoolean(cookies.httpOnly());
out.writeBoolean(cookies.hostOnly());
out.writeBoolean(cookies.persistent());
}
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
String name = (String) in.readObject();
String value = (String) in.readObject();
long expiresAt = in.readLong();
String domain = (String) in.readObject();
String path = (String) in.readObject();
boolean secure = in.readBoolean();
boolean httpOnly = in.readBoolean();
boolean hostOnly = in.readBoolean();
boolean persistent = in.readBoolean();
Cookie.Builder builder = new Cookie.Builder();
builder = builder.name(name);
builder = builder.value(value);
builder = builder.expiresAt(expiresAt);
builder = hostOnly ? builder.hostOnlyDomain(domain) : builder.domain(domain);
builder = builder.path(path);
builder = secure ? builder.secure() : builder;
builder = httpOnly ? builder.httpOnly() : builder;
clientCookies =builder.build();
}
}