OkHttp3实现Cookies管理及持久化
发布时间：2016-01-22 00:00 来源：segmentfault
OKHttp3正式版刚发布了没几天，正好重构之前的代码，于是第一时间入坑了。对okHttp3的一些改变，会陆续写下来，这是第一篇Cookies管理及持久化。
Cookies管理
OkHttp的源码过于复杂，感兴趣的同学可以自行阅读，这里只针对 HttpEngineer 类进行分析，从字面意思即可看出这个类负责http请求的request、response等等操作的处理，而cookies管理也是随着http请求的request、response来处理。
3.0之前
先看networkRequest方法，在里面通过client.getCookieHandler()函数获得了CookieHandler对象，通过该对象拿到cookie并设置到请求头里，请求结束后取得响应后通过networkResponse.headers()函数将请求头获得传入receiveHeaders函数，并将取得的cookie存入getCookieHandler得到的一个CookieHandler对象中去
private Request networkRequest(Request request) throws IOException {
Request.Builder result = request.newBuilder();
//例行省略....
CookieHandler cookieHandler = client.getCookieHandler();
if (cookieHandler != null) {
// Capture the request headers added so far so that they can be offered to the CookieHandler.
// This is mostly to stay close to the RI; it is unlikely any of the headers above would
// affect cookie choice besides "Host".
Map<String, List<String>> headers = OkHeaders.toMultimap(result.build().headers(), null);
Map<String, List<String>> cookies = cookieHandler.get(request.uri(), headers);
// Add any new cookies to the request.
OkHeaders.addCookies(result, cookies);
}
//例行省略....
return result.build();
}
public void readResponse() throws IOException {
//例行省略....
receiveHeaders(networkResponse.headers());
//例行省略....
}
public void receiveHeaders(Headers headers) throws IOException {
CookieHandler cookieHandler = client.getCookieHandler();
if (cookieHandler != null) {
cookieHandler.put(userRequest.uri(), OkHeaders.toMultimap(headers, null));
}
}
CookieHandler对象是OkHttpClient类中的一个属性，传入了这个对象，那么OkHttp就会对cookie进行自动管理
private CookieHandler cookieHandler;
public OkHttpClient setCookieHandler(CookieHandler cookieHandler) {
this.cookieHandler = cookieHandler;
return this;
}
public CookieHandler getCookieHandler() {
return cookieHandler;
}
OkHttpClient client = new OkHttpClient(); client.setCookieHandler(CookieHandler cookieHanlder);
3.0之后
而在OkHttp3中，对cookie而言，新增了两个类 Cookiejar 、 Cookie 两个类，在了解这两个类之前，先去看一下 HttpEngine 关于cookie管理的变化
private Request networkRequest(Request request) throws IOException {
Request.Builder result = request.newBuilder();
//例行省略....
List<Cookie> cookies = client.cookieJar().loadForRequest(request.url());
if (!cookies.isEmpty()) {
result.header("Cookie", cookieHeader(cookies));
}
//例行省略....
return result.build();
}
private String cookieHeader(List<Cookie> cookies) {
StringBuilder cookieHeader = new StringBuilder();
for (int i = 0, size = cookies.size(); i < size; i++) {
if (i > 0) {
cookieHeader.append("; ");
}
Cookie cookie = cookies.get(i);
cookieHeader.append(cookie.name()).append('=').append(cookie.value());
}
return cookieHeader.toString();
}
public void receiveHeaders(Headers headers) throws IOException {
if (client.cookieJar() == CookieJar.NO_COOKIES) return;
List<Cookie> cookies = Cookie.parseAll(userRequest.url(), headers);
if (cookies.isEmpty()) return;
client.cookieJar().saveFromResponse(userRequest.url(), cookies);
}
通过以上几个关键方法，可以很明显的感觉到作者的意图了，为了更加自由定制化的cookie管理。其中 loadForRequest() 、 saveFromResponse() 这两个方法最为关键，分别是在发送时向request header中加入cookie，在接收时，读取response header中的cookie。现在再去看 Cookiejar 这个类，就很好理解了
public interface CookieJar {
/** A cookie jar that never accepts any cookies. */
CookieJar NO_COOKIES = new CookieJar() {
@Override public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
}
@Override public List<Cookie> loadForRequest(HttpUrl url) {
return Collections.emptyList();
}
};
/**
* Saves {@code cookies} from an HTTP response to this store according to this jar's policy.
*
* <p>Note that this method may be called a second time for a single HTTP response if the response
* includes a trailer. For this obscure HTTP feature, {@code cookies} contains only the trailer's
* cookies.
*/
void saveFromResponse(HttpUrl url, List<Cookie> cookies);
/**
* Load cookies from the jar for an HTTP request to {@code url}. This method returns a possibly
* empty list of cookies for the network request.
*
* <p>Simple implementations will return the accepted cookies that have not yet expired and that
* {@linkplain Cookie#matches match} {@code url}.
*/
List<Cookie> loadForRequest(HttpUrl url);
}
so!在OkHttpClient创建时，传入这个CookieJar的实现，就能完成对Cookie的自动管理了
OkHttpClient client = new OkHttpClient.Builder()
.cookieJar(new CookieJar() {
private final HashMap<HttpUrl, List<Cookie>> cookieStore = new HashMap<>();
@Override
public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
cookieStore.put(url, cookies);
}
@Override
public List<Cookie> loadForRequest(HttpUrl url) {
List<Cookie> cookies = cookieStore.get(url);
return cookies != null cookies : new ArrayList<Cookie>();
}
})
.build();
Cookies持久化
对Cookies持久化的方案，与之前版本并无很大区别，还是参考 android-async-http 这个库，主要参考其中两个类:
PersistentCookieStore SerializableHttpCookie与之前版本的区别是要将对 java.net.HttpCookie 这个类的缓存处理换成对 okhttp3.Cookie 的处理，其他方面几乎一样。
废话不多说了，直接上代码
SerializableOkHttpCookies
主要做两件事：
将Cookie对象输出为ObjectStream 将ObjectStream序列化成Cookie对象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();
}
}
PersistentCookieStore
根据一定的规则去缓存或者获取Cookie:
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 假如缓存过期 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 SerializableOkHttpCookies(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(SerializableOkHttpCookies 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 = ((SerializableOkHttpCookies) 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;
}
}
最终效果
完成对Cookie持久化之后，就可以对Cookiejar进行进一步修改了，最终效果：
/**
* 自动管理Cookies
*/
private class CookiesManager implements CookieJar {
private final PersistentCookieStore cookieStore = new PersistentCookieStore(getApplicationContext());
@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;
}
}
Tips
在这样做之前，尝试了使用 Interceptor 和 NetWorkInterceptor 在Http请求request和response时，拦截响应链，加入对Cookie的管理。so！接下来可能会详细介绍下 Interceptor 这个非常酷的实现。
