Android(安卓)OkHttp的Cookie自动化管理

Android中在使用OkHttp这个库的时候，有时候需要持久化Cookie，那么怎么实现呢。OkHttp的内部源码过于复杂，不进行深究，这里只看其中的HttpEngineer里面的部分源码，在发起请求以及请求结束都会调用这个类的几个方法。我们先看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

/** * Populates request with defaults and cookies. * * <p>This client doesn't specify a default {@code Accept} header because it * doesn't know what content types the application is interested in. */private Request networkRequest(Request request) throws IOException {  Request.Builder result = request.newBuilder();  //此处省略n行代码......  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);  }  //此处省略n行代码......  return result.build();}

public void readResponse() throws IOException {  //此处省略n行代码......  receiveHeaders(networkResponse.headers());  //此处省略n行代码......}

public void receiveHeaders(Headers headers) throws IOException {  CookieHandler cookieHandler = client.getCookieHandler();  if (cookieHandler != null) {    cookieHandler.put(userRequest.uri(), OkHeaders.toMultimap(headers, null));  }}

而这个CookieHandler对象是OkHttpClient类中的一个属性，提供了getter和setter方法，默认的构造函数OkHttpClient client = new OkHttpClient();不会创建这个CookieHandler对象。假设我们传入了这个对象，那么OkHttp自然会进行cookie的自动管理了。

private CookieHandler cookieHandler;public OkHttpClient setCookieHandler(CookieHandler cookieHandler) {  this.cookieHandler = cookieHandler;  return this;}public CookieHandler getCookieHandler() {  return cookieHandler;}

那么假设我们将CookieHandler对象传入

OkHttpClient client = new OkHttpClient();client.setCookieHandler(CookieHandler cookieHanlder);

那么，现在关键是如何去实现这个CookieHandler 对象。CookieManager是CookieHandler 的一个子类，其构造函数 public CookieManager(CookieStore store, CookiePolicy cookiePolicy)需要传入两个参数，CookieStore 是一个接口，因此我们实现CookieStore接口中的抽象方法，即可实现这个CookieHandler 对象。参考android-async-http这个库，它具有cookie的自动管理功能，主要我们参考其中的两个类

PersistentCookieStore
SerializableCookie

参考以上两个类并做适当修改，得到了如下两个类，他们的功能就是将cookie保持在SharedPreferences中。

package com.kltz88.okhttp.cookie;/** * User:lizhangqu(513163535@qq.com) * Date:2015-07-13 * Time: 17:31 */import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;import java.net.HttpCookie;public class SerializableHttpCookie implements Serializable {    private static final long serialVersionUID = 6374381323722046732L;    private transient final HttpCookie cookie;    private transient HttpCookie clientCookie;    public SerializableHttpCookie(HttpCookie cookie) {        this.cookie = cookie;    }    public HttpCookie getCookie() {        HttpCookie bestCookie = cookie;        if (clientCookie != null) {            bestCookie = clientCookie;        }        return bestCookie;    }    private void writeObject(ObjectOutputStream out) throws IOException {        out.writeObject(cookie.getName());        out.writeObject(cookie.getValue());        out.writeObject(cookie.getComment());        out.writeObject(cookie.getCommentURL());        out.writeObject(cookie.getDomain());        out.writeLong(cookie.getMaxAge());        out.writeObject(cookie.getPath());        out.writeObject(cookie.getPortlist());        out.writeInt(cookie.getVersion());        out.writeBoolean(cookie.getSecure());        out.writeBoolean(cookie.getDiscard());    }    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {        String name = (String) in.readObject();        String value = (String) in.readObject();        clientCookie = new HttpCookie(name, value);        clientCookie.setComment((String) in.readObject());        clientCookie.setCommentURL((String) in.readObject());        clientCookie.setDomain((String) in.readObject());        clientCookie.setMaxAge(in.readLong());        clientCookie.setPath((String) in.readObject());        clientCookie.setPortlist((String) in.readObject());        clientCookie.setVersion(in.readInt());        clientCookie.setSecure(in.readBoolean());        clientCookie.setDiscard(in.readBoolean());    }}

package com.kltz88.okhttp.cookie;/** * User:lizhangqu(513163535@qq.com) * Date:2015-07-13 * Time: 17:31 */import android.content.Context;import android.content.SharedPreferences;import android.text.TextUtils;import android.util.Log;import java.io.*;import java.net.CookieStore;import java.net.HttpCookie;import java.net.URI;import java.net.URISyntaxException;import java.util.*;import java.util.concurrent.ConcurrentHashMap;/** * A persistent cookie store which implements the Apache HttpClient CookieStore interface. * Cookies are stored and will persist on the user's device between application sessions since they * are serialized and stored in SharedPreferences. Instances of this class are * designed to be used with AsyncHttpClient#setCookieStore, but can also be used with a * regular old apache HttpClient/HttpContext if you prefer. */public class PersistentCookieStore implements CookieStore {    private static final String LOG_TAG = "PersistentCookieStore";    private static final String COOKIE_PREFS = "CookiePrefsFile";    private static final String COOKIE_NAME_PREFIX = "cookie_";    private final HashMap<String, ConcurrentHashMap<String, HttpCookie>> cookies;    private final SharedPreferences cookiePrefs;    /** * Construct a persistent cookie store. * * @param context Context to attach cookie store to */    public PersistentCookieStore(Context context) {        cookiePrefs = context.getSharedPreferences(COOKIE_PREFS, 0);        cookies = new HashMap<String, ConcurrentHashMap<String, HttpCookie>>();        // Load any previously stored cookies into the store        Map<String, ?> prefsMap = cookiePrefs.getAll();        for(Map.Entry<String, ?> entry : prefsMap.entrySet()) {            if (((String)entry.getValue()) != null && !((String)entry.getValue()).startsWith(COOKIE_NAME_PREFIX)) {                String[] cookieNames = TextUtils.split((String)entry.getValue(), ",");                for (String name : cookieNames) {                    String encodedCookie = cookiePrefs.getString(COOKIE_NAME_PREFIX + name, null);                    if (encodedCookie != null) {                        HttpCookie decodedCookie = decodeCookie(encodedCookie);                        if (decodedCookie != null) {                            if(!cookies.containsKey(entry.getKey()))                                cookies.put(entry.getKey(), new ConcurrentHashMap<String, HttpCookie>());                            cookies.get(entry.getKey()).put(name, decodedCookie);                        }                    }                }            }        }    }    @Override    public void add(URI uri, HttpCookie cookie) {        String name = getCookieToken(uri, cookie);        // Save cookie into local store, or remove if expired        if (!cookie.hasExpired()) {            if(!cookies.containsKey(uri.getHost()))                cookies.put(uri.getHost(), new ConcurrentHashMap<String, HttpCookie>());            cookies.get(uri.getHost()).put(name, cookie);        } else {            if(cookies.containsKey(uri.toString()))                cookies.get(uri.getHost()).remove(name);        }        // Save cookie into persistent store        SharedPreferences.Editor prefsWriter = cookiePrefs.edit();        prefsWriter.putString(uri.getHost(), TextUtils.join(",", cookies.get(uri.getHost()).keySet()));        prefsWriter.putString(COOKIE_NAME_PREFIX + name, encodeCookie(new SerializableHttpCookie(cookie)));        prefsWriter.commit();    }    protected String getCookieToken(URI uri, HttpCookie cookie) {        return cookie.getName() + cookie.getDomain();    }    @Override    public List<HttpCookie> get(URI uri) {        ArrayList<HttpCookie> ret = new ArrayList<HttpCookie>();        if(cookies.containsKey(uri.getHost()))            ret.addAll(cookies.get(uri.getHost()).values());        return ret;    }    @Override    public boolean removeAll() {        SharedPreferences.Editor prefsWriter = cookiePrefs.edit();        prefsWriter.clear();        prefsWriter.commit();        cookies.clear();        return true;    }    @Override    public boolean remove(URI uri, HttpCookie cookie) {        String name = getCookieToken(uri, cookie);        if(cookies.containsKey(uri.getHost()) && cookies.get(uri.getHost()).containsKey(name)) {            cookies.get(uri.getHost()).remove(name);            SharedPreferences.Editor prefsWriter = cookiePrefs.edit();            if(cookiePrefs.contains(COOKIE_NAME_PREFIX + name)) {                prefsWriter.remove(COOKIE_NAME_PREFIX + name);            }            prefsWriter.putString(uri.getHost(), TextUtils.join(",", cookies.get(uri.getHost()).keySet()));            prefsWriter.commit();            return true;        } else {            return false;        }    }    @Override    public List<HttpCookie> getCookies() {        ArrayList<HttpCookie> ret = new ArrayList<HttpCookie>();        for (String key : cookies.keySet())            ret.addAll(cookies.get(key).values());        return ret;    }    @Override    public List<URI> getURIs() {        ArrayList<URI> ret = new ArrayList<URI>();        for (String key : cookies.keySet())            try {                ret.add(new URI(key));            } catch (URISyntaxException e) {                e.printStackTrace();            }        return ret;    }    /** * Serializes Cookie object into String * * @param cookie cookie to be encoded, can be null * @return cookie encoded as String */    protected String encodeCookie(SerializableHttpCookie 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());    }    /** * Returns cookie decoded from cookie string * * @param cookieString string of cookie as returned from http request * @return decoded cookie or null if exception occured */    protected HttpCookie decodeCookie(String cookieString) {        byte[] bytes = hexStringToByteArray(cookieString);        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes);        HttpCookie cookie = null;        try {            ObjectInputStream objectInputStream = new ObjectInputStream(byteArrayInputStream);            cookie = ((SerializableHttpCookie) objectInputStream.readObject()).getCookie();        } catch (IOException e) {            Log.d(LOG_TAG, "IOException in decodeCookie", e);        } catch (ClassNotFoundException e) {            Log.d(LOG_TAG, "ClassNotFoundException in decodeCookie", e);        }        return cookie;    }    /** * Using some super basic byte array &lt;-&gt; hex conversions so we don't have to rely on any * large Base64 libraries. Can be overridden if you like! * * @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);    }    /** * Converts hex values from strings to byte arra * * @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;    }}

使用的时候，在发起请求前对CookieHandler进行设置，后续的cookie全都是自动管理，无需你关心cookie的保存于读取

OkHttpClient client = new OkHttpClient();client.setCookieHandler(new CookieManager(        new PersistentCookieStore(getApplicationContext()),        CookiePolicy.ACCEPT_ALL));

这样，实现模拟登录，抓取一些数据就方便很多了，再也不用手动处理cookie了。

更多相关文章

随机推荐