你应该知道的那些Android小经验

1.枚举提供类型安全

Android代码替代枚举的正确之道

Paste_Image.png

2.匿名token

作用：防止被人恶意刷接口。
情景：当应用，在非登录状态下也可以使用的情况下，需要匿名token。
解决：要去服务器请求一个匿名token

3微信分享没有回调

.wxapi.WXEntryActivity必须在包名下面。
微信分享没有回调问题

4android中网络请求中页面关闭了会怎么样?

问题：android中网络请求中页面关闭了会怎么样
以activity为例子，
1.可以在onDestroy里cancel掉所有网络请求。
2.也可以采用虚引用的方式
虚引用 ：不能单独使用，主要是用于追踪对象被垃圾回收的状态。通过PhantomReference类和引用队列ReferenceQueue类联合使用实现

 * 为每个  NetCall 建立一个与 Tag(Object) 的引用. 当 Tag 被 JVM 回收后,自动关闭 NetCall. * */
public class BJNetResourceManager {   
 private Object mDefaultObject = new Object();    
private ReferenceQueue<Object> mReferenceQueue = new ReferenceQueue<>();    
private Map<Integer, ResourceReference> mResourceRefMap = new ConcurrentHashMap<>();    
private ResourceCheckThread mResourceCheckThread = new ResourceCheckThread();    
public BJNetResourceManager() {       mResourceCheckThread.start();    
}    
public void release() {    }    
public void addNetCall(Object tag, BJNetCall call) {        int key = mDefaultObject.hashCode();        if (tag != null) {           key = tag.hashCode();        }        if (mResourceRefMap.containsKey(key)) {            ResourceReference reference = mResourceRefMap.get(key);            reference.add(call);        } else {            ResourceReference reference = new ResourceReference(tag == null ? mDefaultObject : tag, mReferenceQueue);            reference.add(call);            mResourceRefMap.put(key, reference);        }    }    public void removeNetCall(Object tag, BJNetCall call) {        int key = mDefaultObject.hashCode();        if (tag != null) {            key = tag.hashCode();        }        if (mResourceRefMap.containsKey(key)) {            ResourceReference reference = mResourceRefMap.get(key);            reference.remove(call);        } else {        }    }    public void removeAll(Object tag) {        int key = mDefaultObject.hashCode();        if (tag != null) {            key = tag.hashCode();        }        if (mResourceRefMap.containsKey(key)) {            ResourceReference reference = mResourceRefMap.get(key);            reference.cancelAll();            mResourceRefMap.remove(key);        }    }    private static class ResourceReference extends PhantomReference<Object> {        private int tagId;        private String tagName;        private List<BJNetCall> list;        /**         * Constructs a new phantom reference and registers it with the given         * reference queue. The reference queue may be {@code null}, but this case         * does not make any sense, since the reference will never be enqueued, and         * the {@link #get()} method always returns {@code null}.         *         * @param r the referent to track         * @param q the queue to register the phantom reference object with         */        public ResourceReference(Object r, ReferenceQueue<? super Object> q) {            super(r, q);            this.tagId = r.hashCode();            this.tagName = r.getClass().getSimpleName();            this.list = Collections.synchronizedList(new LinkedList<BJNetCall>());        }        public int getTagId() {            return tagId;        }        public String getTagName() {            return tagName;        }        public void add(BJNetCall call) {            list.add(call);        }        public void remove(BJNetCall call) {            list.remove(call);        }        public void cancelAll() {            for (BJNetCall call : list) {                try {                    call.cancel();                } catch (Exception e) {                    e.printStackTrace();                }            }            list.clear();        }    }    private class ResourceCheckThread extends Thread {        public ResourceCheckThread()  {            super("NetResourceCheckThread");            setPriority(Thread.MAX_PRIORITY);            setDaemon(true);        }        @Override        public void run() {            ResourceReference reference = null;            while (! interrupted()) {                if (reference != null) {                    reference.cancelAll();                    reference.clear();                    mResourceRefMap.remove(reference.getTagId());                    Log.i("BJNetResource", "["+reference.getTagName() +"("+reference.getTagId()+")"+" is released and cancel calls auto.]");                }                // default tag 域中可能有已经执行完成了的 call. 将其回收掉                ResourceReference defaultReference =  mResourceRefMap.get(mDefaultObject.hashCode());                if (defaultReference != null) {                    Iterator<BJNetCall> iterator = defaultReference.list.listIterator();                    while (iterator.hasNext()) {                        if (! iterator.next().isExecuted()) {                            iterator.remove();                            Log.i("BJNetResource", "["+defaultReference.getTagName() +"("+defaultReference.getTagId()+")"+" is cleanup and cancel calls auto.]");                        }                    }                }                try {                    // remove() 会 wait 住线程                    reference = (ResourceReference) mReferenceQueue.remove(1000);                }  catch (Exception e) {                    e.printStackTrace();                }            }        }    }}