Android Okhttp完美同步持久Cookie实现免登录

通过对Retrofit2.0的<Retrofit 2.0 超能实践，完美支持Https传输>基础入门和案例实践，掌握了怎么样使用Retrofit访问网络，加入自定义header，包括加入SSL证书，基本的调试基础，但是正常的开发中会涉及cookie同步问题，可以实现一些自动或免登录登陆问题，接下来进入cookie同步姿势

Cookie

Cookies是一种能够让网站服务器把少量数据储存到客户端的硬盘或内存，或是从客户端的硬盘读取数据的一种技术。Cookies是当你浏览某网站时，由Web服务器置于你硬盘上的一个非常小的文本文件，它可以记录你的用户ID、密码、浏览过的网页、停留的时间等信息。当你再次来到该网站时，网站通过读取Cookies，得知你的相关信息，就可以做出相应的动作，如在页面显示欢迎你的标语，或者让你不用输入ID、密码就直接登录等等。

从本质上讲，它可以看作是你的身份证。但Cookies不能作为代码执行，也不会传送病毒，且为你所专有，并只能由提供它的服务器来读取。保存的信息片断以“名/值”对(name-value pairs)的形式储存，一个“名/值”对仅仅是一条命名的数据。一个网站只能取得它放在你的电脑中的信息，它无法从其它的Cookies文件中取得信息，也无法得到你的电脑上的其它任何东西。

Cookies中的内容大多数经过了加密处理，因此一般用户看来只是一些毫无意义的字母数字组合，只有服务器的CGI处理程序才知道它们真正的含义。

Cookie也是http的会话跟踪技术，也包含web端的session。cookie的作用就是为了解决HTTP协议无状态的缺陷所作的努力.

方式一：

自定义cookie

HttpClient中大家都知道加入cookie的方式

AsyncHttpClient client = new AsyncHttpClient();
PersistentCookieStore myCookieStore = new PersistentCookieStore(MainActivity.this);
client.setCookieStore(myCookieStore);

因此Retrofit中需自我实现一个PersistentCookieStore 用来储存OkHttpCookies。

-PersistentCookieStore

/**
* Created by LIUYONGKUI on 2016-06-09.
*/
public class PersistentCookieStore {
private static final String LOG_TAG = "PersistentCookieStore";
private static final String COOKIE_PREFS = "Cookies_Prefs";

private final Map<String, ConcurrentHashMap<String, Cookie>> cookies;
private final SharedPreferences cookiePrefs;

public 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<String, ?> prefsMap = cookiePrefs.getAll();
for (Map.Entry<String, ?> 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<String, Cookie>());
}
cookies.get(entry.getKey()).put(name, decodedCookie);
}
}
}
}
}

protected String getCookieToken(Cookie cookie) {
return cookie.name() + "@" + cookie.domain();
}

public 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()) {
if (!cookies.containsKey(url.host())) {
cookies.put(url.host(), new ConcurrentHashMap<String, Cookie>());
}
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
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.putString(url.host(), TextUtils.join(",", cookies.get(url.host()).keySet()));
prefsWriter.putString(name, encodeCookie(new OkHttpCookies(cookie)));
prefsWriter.apply();
}

public List<Cookie> get(HttpUrl url) {
ArrayList<Cookie> ret = new ArrayList<>();
if (cookies.containsKey(url.host()))
ret.addAll(cookies.get(url.host()).values());
return ret;
}

public boolean removeAll() {
SharedPreferences.Editor prefsWriter = cookiePrefs.edit();
prefsWriter.clear();
prefsWriter.apply();
cookies.clear();
return true;
}

public 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 List<Cookie> getCookies() {
ArrayList<Cookie> 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(OkHttpCookies cookie) {
if (cookie == null)
return null;
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
ObjectOutputStream outputStream = new ObjectOutputStream(os);
outputStream.writeObject(cookie);
} catch (IOException e) {
Log.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 = ((OkHttpCookies) objectInputStream.readObject()).getCookies();
} catch (IOException e) {
Log.d(LOG_TAG, "IOException in decodeCookie", e);
} catch (ClassNotFoundException e) {
Log.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;
}

- OkHttpCookies

需要实现序列化的 OkHttpCookies 用来持久OkHttpCookies

/**
* Created by LIUYONGKUI on 2016-05-20.
*/
public class OkHttpCookies implements Serializable {

private transient final Cookie cookies;
private transient Cookie clientCookies;

public OkHttpCookies(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();
}

}

-自定义CookieManger

实现有一个自定义的CookieManger来管理cookies,实现以K-V结构获取set,getCookier

public class CookieManger implements CookieJar {

public static String APP_PLATFORM = "app-platform";

private static Context mContext;

private static PersistentCookieStore cookieStore;

public CookieManger(Context context) {
mContext = context;
if (cookieStore == null ) {
cookieStore = new PersistentCookieStore(mContext);
}

}

@Override
public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
if (cookies != null && cookies.size() > 0) {
for (Cookie item : cookies) {
cookieStore.add(url, item);
}
}
}

@Override
public List<Cookie> loadForRequest(HttpUrl url) {
List<Cookie> cookies =cookieStore.get(url);
return cookies;
}

static class Customer {

private String userID;
private String token;

public Customer(String userID, String token) {
this.userID = userID;
this.token = token;
}

public String getUserID() {
return userID;
}

public void setUserID(String userID) {
this.userID = userID;
}

public String getToken() {
return token;
}

public void setToken(String token) {
this.token = token;
}

}

- Retrofit加入cookie

OkHttpClient okHttpClient = new OkHttpClient.Builder()
.addNetworkInterceptor(
new HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.HEADERS))
.cookieJar(new CookieManger(context))
.addInterceptor(loginInterceptor)
.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS)
.build();

Retrofit retrofit = new Retrofit.Builder()
.client(okHttpClient)
.build();

总结

实现加入cookies持久，实现免登陆基本步骤

方式二：

方法一可能对某些网站不兼容，可以借助retfoit的拦截器实现

用来加入cookie

public class ReadCookiesInterceptor implements   Interceptor {

@Override
public Response intercept(Chain chain) throws IOException {
Request.Builder builder = chain.request().newBuilder();
HashSet<String> preferences = (HashSet) Preferences.getDefaultPreferences().getStringSet(Preferences.PREF_COOKIES, new HashSet<>());
for (String cookie : preferences) {
builder.addHeader("Cookie", cookie);
Log.v("OkHttp", "Adding Header: " + cookie); // This is done so I know which headers are being added; this interceptor is used after the normal logging of OkHttp
}

return chain.proceed(builder.build());
}

}

用来保存Cookies

public class SaveCookiesInterceptor implements Interceptor {
@Override
public Response intercept(Chain chain) throws IOException {
Response originalResponse = chain.proceed(chain.request());

if (!originalResponse.headers("Set-Cookie").isEmpty()) {
HashSet<String> cookies = new HashSet<>();

for (String header : originalResponse.headers("Set-Cookie")) {
cookies.add(header);
}

Preferences.getDefaultPreferences().edit()
.putStringSet(Preferences.PREF_COOKIES, cookies)
.apply();
}

return originalResponse;
}

}

okhttp

OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.interceptors().add(new ReadCookiesInterceptor());
okHttpClient.interceptors().add(new SaveCookiesInterceptor());

Retrofit

Retrofit retrofit = new Retrofit.Builder()
.client(okHttpClient)
.build();