package com.example.kj_eventbus;

public class EventMessage {
    public String name;

    public EventMessage(String name) {
        this.name = name;
    }
}

public class MainActivity extends AppCompatActivity {

 	...
 	//接收消息的方法
    @Subscribe(threadMode = ThreadMode.MAIN)
    public void eventBus(EventMessage msg) {
        Toast.makeText(this, msg.name, Toast.LENGTH_SHORT).show();
    }

    public void jump(View view) {
        //注册接收消息的类
        EventBus.getDefault().register(this);
        startActivity(new Intent(this, SendMsgAct.class));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //取消注册
        EventBus.getDefault().unregister(this);
    }
}

public class SendMsgAct extends AppCompatActivity {
	...
    public void send(View view) {
       new Thread(new Runnable() {
            @Override
            public void run() {
                //发送消息
                EventBus.getDefault().post(new EventMessage("你好朋羽毛！！"));
            }
        }).start();
    }
}

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
public @interface Subscribe {
    //接收消息的线程
    ThreadMode threadMode() default ThreadMode.POSTING;
    //是否是粘性消息
    boolean sticky() default false;
	//优先级
    int priority() default 0;
}


public enum ThreadMode {
    POSTING,
    MAIN,
    MAIN_ORDERED,
    BACKGROUND,
    ASYNC
}

//单例 
static volatile EventBus defaultInstance;

public static EventBus getDefault() {
    if (defaultInstance == null) {
        synchronized (EventBus.class) {
            if (defaultInstance == null) {
                defaultInstance = new EventBus();
            }
        }
    }
    return defaultInstance;
}

public EventBus() {
    this(DEFAULT_BUILDER);
}
//建造者（将构造参数分离了出来）
EventBus(EventBusBuilder builder) {
    ...
        sendSubscriberExceptionEvent = builder.sendSubscriberExceptionEvent;
    sendNoSubscriberEvent = builder.sendNoSubscriberEvent;
    throwSubscriberException = builder.throwSubscriberException;
    eventInheritance = builder.eventInheritance;
    executorService = builder.executorService;
}
public static EventBusBuilder builder() {
    return new EventBusBuilder();
}

public void register(Object subscriber) {
    Class<?> subscriberClass = subscriber.getClass();
    //1
    List<SubscriberMethod> subscriberMethods = subscriberMethodFinder.findSubscriberMethods(subscriberClass);
    //2   
    synchronized (this) {
        for (SubscriberMethod subscriberMethod : subscriberMethods) {
            subscribe(subscriber, subscriberMethod);
        }
    }
}

//接收消息的方法的封装实体类
public class SubscriberMethod {
    final Method method;//方法
    final ThreadMode threadMode;
    final Class<?> eventType;//MessagedType
    final int priority;
    final boolean sticky;
    /** Used for efficient comparison */
    String methodString;
}

 //类跟对应方法的实体类
 class Subscription {
    final Object subscriber;//注册类
    final SubscriberMethod subscriberMethod;
 }

List<SubscriberMethod> findSubscriberMethods(Class<?> subscriberClass) {
    //从cache中获取
    List<SubscriberMethod> subscriberMethods = METHOD_CACHE.get(subscriberClass);
    if (subscriberMethods != null) {
        return subscriberMethods;
    }
    //ignoreGeneratedIndex如果为true，那么使用apt获取subscriberClass中接收消息的方法集合
    //为false，那么通过反射获取
    if (ignoreGeneratedIndex) {
        subscriberMethods = findUsingReflection(subscriberClass);
    } else {
        subscriberMethods = findUsingInfo(subscriberClass);
    }
    if (subscriberMethods.isEmpty()) {
       ...
    } else {
        //放入cache
        METHOD_CACHE.put(subscriberClass, subscriberMethods);
        return subscriberMethods;
    }
}

private List<SubscriberMethod> findUsingInfo(Class<?> subscriberClass) {
    FindState findState = prepareFindState();
    findState.initForSubscriber(subscriberClass);
    while (findState.clazz != null) {
        findState.subscriberInfo = getSubscriberInfo(findState);
        if (findState.subscriberInfo != null) {
            SubscriberMethod[] array = findState.subscriberInfo.getSubscriberMethods();
            for (SubscriberMethod subscriberMethod : array) {
                if (findState.checkAdd(subscriberMethod.method, subscriberMethod.eventType)) {
                    findState.subscriberMethods.add(subscriberMethod);
                }
            }
        } else {
            //通过反射调用
            findUsingReflectionInSingleClass(findState);
        }
        findState.moveToSuperclass();
    }
    return getMethodsAndRelease(findState);
}

private void findUsingReflectionInSingleClass(FindState findState) {
        Method[] methods;
       	...
        methods = findState.clazz.getDeclaredMethods();
      	...
        for (Method method : methods) {
            ////获取方法修饰符（public private static,,
            //方法必须是publit not-static  not-abstract
            int modifiers = method.getModifiers();
            if ((modifiers & Modifier.PUBLIC) != 0 && (modifiers & MODIFIERS_IGNORE) == 0) {
                Class<?>[] parameterTypes = method.getParameterTypes();
                if (parameterTypes.length == 1) {
                    //获取方法注解
                    Subscribe subscribeAnnotation = method.getAnnotation(Subscribe.class);
                    if (subscribeAnnotation != null) {
                        //获取MesageType
                        Class<?> eventType = parameterTypes[0];
                        if (findState.checkAdd(method, eventType)) {
                            //获取注解的值，将method，MessageType，ThreadMode，Prority，Sticky关联起来
                            ThreadMode threadMode = subscribeAnnotation.threadMode();
                            findState.subscriberMethods.add(new SubscriberMethod(method, eventType, threadMode,subscribeAnnotation.priority(), subscribeAnnotation.sticky()));
                        }
                    }
                } 
                ...
                }
            } 
            ...
        }
    }

private List<SubscriberMethod> getMethodsAndRelease(FindState findState) {
    List<SubscriberMethod> subscriberMethods = new ArrayList<>(findState.subscriberMethods);
    findState.recycle();
    synchronized (FIND_STATE_POOL) {
        for (int i = 0; i < POOL_SIZE; i++) {
            if (FIND_STATE_POOL[i] == null) {
                FIND_STATE_POOL[i] = findState;
                break;
            }
        }
    }
    return subscriberMethods;
}

private void subscribe(Object subscriber, SubscriberMethod subscriberMethod) {
    Class<?> eventType = subscriberMethod.eventType;
    //1:初始化subscriptionsByEventType
    Subscription newSubscription = new Subscription(subscriber, subscriberMethod);
    //异步可以同时读写的list：CopyOnWriteArrayList
    CopyOnWriteArrayList<Subscription> subscriptions = subscriptionsByEventType.get(eventType);
    if (subscriptions == null) {
        subscriptions = new CopyOnWriteArrayList<>();
        subscriptionsByEventType.put(eventType, subscriptions);
    } else {
       ...
    }

    int size = subscriptions.size();
    for (int i = 0; i <= size; i++) {
        if (i == size || subscriberMethod.priority > subscriptions.get(i).subscriberMethod.priority) {
            subscriptions.add(i, newSubscription);
            break;
        }
    }
	//2:初始化typesBySubscriber
    List<Class<?>> subscribedEvents = typesBySubscriber.get(subscriber);
    if (subscribedEvents == null) {
        subscribedEvents = new ArrayList<>();
        typesBySubscriber.put(subscriber, subscribedEvents);
    }
    subscribedEvents.add(eventType);

    if (subscriberMethod.sticky) {
        ...
    }
}

public void post(Object event) {
    //将消息放入postingState的queue中
    PostingThreadState postingState = currentPostingThreadState.get();
    List<Object> eventQueue = postingState.eventQueue;
    eventQueue.add(event);

    if (!postingState.isPosting) {
        postingState.isMainThread = isMainThread();
        postingState.isPosting = true;
      	...
        try {
            while (!eventQueue.isEmpty()) {
                postSingleEvent(eventQueue.remove(0), postingState);
            }
        } finally {
            postingState.isPosting = false;
            postingState.isMainThread = false;
        }
    }
}
//其中的currentPostingThreadState是ThreadLocal（以线程为单位，存放变量，也就是同一个变量在不同线程中是不一样的）
private final ThreadLocal<PostingThreadState> currentPostingThreadState = new ThreadLocal<PostingThreadState>() {
    @Override
    protected PostingThreadState initialValue() {
        return new PostingThreadState();
    }
};

//PostingThreadState
final static class PostingThreadState {
    final List<Object> eventQueue = new ArrayList<>();
    boolean isPosting;
    boolean isMainThread;
    Subscription subscription;
    Object event;
    boolean canceled;
}

private boolean isMainThread() {
    return mainThreadSupport != null ? mainThreadSupport.isMainThread() : true;
}

EventBus(EventBusBuilder builder) {
	...
       mainThreadSupport = builder.getMainThreadSupport();
       mainThreadPoster = mainThreadSupport != null ? mainThreadSupport.createPoster(this) : null;
       backgroundPoster = new BackgroundPoster(this);
       asyncPoster = new AsyncPoster(this);
    	...
   }

MainThreadSupport getMainThreadSupport() {
    if (mainThreadSupport != null) {
        return mainThreadSupport;
    } else if (Logger.AndroidLogger.isAndroidLogAvailable()) {
        Object looperOrNull = getAndroidMainLooperOrNull();
        return looperOrNull == null ? null :
        new MainThreadSupport.AndroidHandlerMainThreadSupport((Looper) looperOrNull);
    } else {
        return null;
    }
}

public static class AndroidLogger implements Logger {
      static final boolean ANDROID_LOG_AVAILABLE;

      static {
          boolean android = false;
          try {
              android = Class.forName("android.util.Log") != null;
          } catch (ClassNotFoundException e) {
              // OK
          }
          ANDROID_LOG_AVAILABLE = android;
      }

      public static boolean isAndroidLogAvailable() {
          return ANDROID_LOG_AVAILABLE;
      }
}

Object getAndroidMainLooperOrNull() {
    ...
    return Looper.getMainLooper();
    ...
}

class AndroidHandlerMainThreadSupport implements MainThreadSupport {

    private final Looper looper;

    public AndroidHandlerMainThreadSupport(Looper looper) {
        this.looper = looper;
    }

    @Override
    public boolean isMainThread() {
        return looper == Looper.myLooper();
    }
  ...
}

private void postSingleEvent(Object event, PostingThreadState postingState) throws Error {
    Class<?> eventClass = event.getClass();
    boolean subscriptionFound = false;
    //是否算父类，默认是true
    if (eventInheritance) {
        List<Class<?>> eventTypes = lookupAllEventTypes(eventClass);
        int countTypes = eventTypes.size();
        for (int h = 0; h < countTypes; h++) {
            Class<?> clazz = eventTypes.get(h);
            subscriptionFound |= postSingleEventForEventType(event, postingState, clazz);
        }
    } else {
        subscriptionFound = postSingleEventForEventType(event, postingState, eventClass);
    }
    if (!subscriptionFound) {
        if (logNoSubscriberMessages) {
            logger.log(Level.FINE, "No subscribers registered for event " + eventClass);
        }
        if (sendNoSubscriberEvent && eventClass != NoSubscriberEvent.class &&
            eventClass != SubscriberExceptionEvent.class) {
            post(new NoSubscriberEvent(this, event));
        }
    }
}

private static List<Class<?>> lookupAllEventTypes(Class<?> eventClass) {
    synchronized (eventTypesCache) {
        List<Class<?>> eventTypes = eventTypesCache.get(eventClass);
        if (eventTypes == null) {
            eventTypes = new ArrayList<>();
            Class<?> clazz = eventClass;
            while (clazz != null) {
                eventTypes.add(clazz);
                addInterfaces(eventTypes, clazz.getInterfaces());
                clazz = clazz.getSuperclass();
            }
            eventTypesCache.put(eventClass, eventTypes);
        }
        return eventTypes;
    }
}

private boolean postSingleEventForEventType(Object event, PostingThreadState postingState, Class<?> eventClass) {
    CopyOnWriteArrayList<Subscription> subscriptions;
    synchronized (this) {
        subscriptions = subscriptionsByEventType.get(eventClass);
    }
    if (subscriptions != null && !subscriptions.isEmpty()) {
        for (Subscription subscription : subscriptions) {
            postingState.event = event;
            postingState.subscription = subscription;
            boolean aborted = false;
            try {
                postToSubscription(subscription, event, postingState.isMainThread);
                aborted = postingState.canceled;
            } finally {
                postingState.event = null;
                postingState.subscription = null;
                postingState.canceled = false;
            }
            if (aborted) {
                break;
            }
        }
        return true;
    }
    return false;
}

private void postToSubscription(Subscription subscription, Object event, boolean isMainThread) {
    switch (subscription.subscriberMethod.threadMode) {
        case POSTING:
            invokeSubscriber(subscription, event);
            break;
        case MAIN:
            if (isMainThread) {
                invokeSubscriber(subscription, event);
            } else {
                mainThreadPoster.enqueue(subscription, event);
            }
            break;
        case MAIN_ORDERED:
            if (mainThreadPoster != null) {
                mainThreadPoster.enqueue(subscription, event);
            } else {
                // temporary: technically not correct as poster not decoupled from subscriber
                invokeSubscriber(subscription, event);
            }
            break;
        case BACKGROUND:
            if (isMainThread) {
                backgroundPoster.enqueue(subscription, event);
            } else {
                invokeSubscriber(subscription, event);
            }
            break;
        case ASYNC:
            asyncPoster.enqueue(subscription, event);
            break;
        default:
            throw new IllegalStateException("Unknown thread mode: " + subscription.subscriberMethod.threadMode);
    }
}

mainThreadPoster = mainThreadSupport != null ? mainThreadSupport.createPoster(this) : null;

class AndroidHandlerMainThreadSupport implements MainThreadSupport {

	...
    @Override
    public Poster createPoster(EventBus eventBus) {
        return new HandlerPoster(eventBus, looper, 10);
    }
}

public class HandlerPoster extends Handler implements Poster {

    private final PendingPostQueue queue;
    private final int maxMillisInsideHandleMessage;
    private final EventBus eventBus;
    private boolean handlerActive;

    protected HandlerPoster(EventBus eventBus, Looper looper, int maxMillisInsideHandleMessage) {
        super(looper);
        this.eventBus = eventBus;
        this.maxMillisInsideHandleMessage = maxMillisInsideHandleMessage;
        queue = new PendingPostQueue();
    }

    public void enqueue(Subscription subscription, Object event) {
        PendingPost pendingPost = PendingPost.obtainPendingPost(subscription, event);
        synchronized (this) {
            queue.enqueue(pendingPost);
            if (!handlerActive) {
                handlerActive = true;
                if (!sendMessage(obtainMessage())) {
                    throw new EventBusException("Could not send handler message");
                }
            }
        }
    }

    @Override
    public void handleMessage(Message msg) {
        boolean rescheduled = false;
        try {
            long started = SystemClock.uptimeMillis();
            while (true) {
                PendingPost pendingPost = queue.poll();
                if (pendingPost == null) {
                    synchronized (this) {
                        // Check again, this time in synchronized
                        pendingPost = queue.poll();
                        if (pendingPost == null) {
                            handlerActive = false;
                            return;
                        }
                    }
                }
                eventBus.invokeSubscriber(pendingPost);
                long timeInMethod = SystemClock.uptimeMillis() - started;
                if (timeInMethod >= maxMillisInsideHandleMessage) {
                    if (!sendMessage(obtainMessage())) {
                        throw new EventBusException("Could not send handler message");
                    }
                    rescheduled = true;
                    return;
                }
            }
        } finally {
            handlerActive = rescheduled;
        }
    }
}

static PendingPost obtainPendingPost(Subscription subscription, Object event) {
    synchronized (pendingPostPool) {
        int size = pendingPostPool.size();
        if (size > 0) {
            PendingPost pendingPost = pendingPostPool.remove(size - 1);
            pendingPost.event = event;
            pendingPost.subscription = subscription;
            pendingPost.next = null;
            return pendingPost;
        }
    }
    return new PendingPost(event, subscription);
}

void invokeSubscriber(PendingPost pendingPost) {
    Object event = pendingPost.event;
    Subscription subscription = pendingPost.subscription;
    PendingPost.releasePendingPost(pendingPost);
    if (subscription.active) {
        invokeSubscriber(subscription, event);
    }
}

void invokeSubscriber(Subscription subscription, Object event) {
	...
    subscription.subscriberMethod.method.invoke(subscription.subscriber, event);
	...
}

final class BackgroundPoster implements Runnable, Poster {

    private final PendingPostQueue queue;
    private final EventBus eventBus;

    private volatile boolean executorRunning;

    BackgroundPoster(EventBus eventBus) {
        this.eventBus = eventBus;
        queue = new PendingPostQueue();
    }

    public void enqueue(Subscription subscription, Object event) {
        PendingPost pendingPost = PendingPost.obtainPendingPost(subscription, event);
        synchronized (this) {
            queue.enqueue(pendingPost);
            if (!executorRunning) {
                executorRunning = true;
                eventBus.getExecutorService().execute(this);
            }
        }
    }

    @Override
    public void run() {
        try {
            try {
                while (true) {
                    PendingPost pendingPost = queue.poll(1000);
                    if (pendingPost == null) {
                        synchronized (this) {
                            // Check again, this time in synchronized
                            pendingPost = queue.poll();
                            if (pendingPost == null) {
                                executorRunning = false;
                                return;
                            }
                        }
                    }
                    eventBus.invokeSubscriber(pendingPost);
                }
            } catch (InterruptedException e) {
                eventBus.getLogger().log(Level.WARNING, Thread.currentThread().getName() + " was interruppted", e);
            }
        } finally {
            executorRunning = false;
        }
    }

}

class Solution {
    public int combinationSum4(int[] nums, int target) {
        //dp[target]=sum(dp[target-nums[i]]);  i:0~~nums.length-1;
        int [] dp=new int[target+1];
        
        for(int i =0;i<dp.length;i++){
            dp[i]=0;
        }
        
        dp[0]=1;
        
        for(int i =1;i<dp.length;i++){
            for(int j =0;j<nums.length;j++){
                if(i>=nums[j]){
                    dp[i]+=dp[i-nums[j]];
                }
            }
            System.out.println(dp[i]);
        }
        
        return dp[target];
    }
}

package com.example.mylibrary.audio;

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Environment;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
* pcm录音utils
* @anthor kb_jay
* create at 2018/8/21 上午10:37
*/
public class AudioRecordUtil {
    private static AudioRecordUtil mInstance;
    private AudioRecord recorder;
    //声音源
    private static int audioSource = MediaRecorder.AudioSource.MIC;
    //录音的采样频率
    private static int audioRate = 16000;
    //录音的声道，单声道
    private static int audioChannel = AudioFormat.CHANNEL_IN_DEFAULT;
    //量化的精度
    private static int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
    //缓存的大小
    private static int bufferSize = AudioRecord.getMinBufferSize(audioRate, audioChannel, audioFormat);
    //记录播放状态
    private boolean isRecording = false;
    //数字信号数组
    private byte[] noteArray;
    //PCM文件
    private File pcmFile;
    //wav文件
    private File wavFile;
    //文件输出流
    private OutputStream os;
    //文件根目录
    private String basePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/xiaoIceStory/";

    //pcm文件目录
    private String inFileName = basePath + "/encode.pcm";

    public String getPcmFilePath() {
        return inFileName;
    }

    private AudioRecordUtil() {
        //创建文件
        createFile();
    }

    //创建文件夹,首先创建目录，然后创建对应的文件
    private void createFile() {
        File baseFile = new File(basePath);
        if (!baseFile.exists()) {
            baseFile.mkdirs();
        }
        pcmFile = new File(basePath + "/encode.pcm");

        if (pcmFile.exists()) {
            pcmFile.delete();
        }
        try {
            pcmFile.createNewFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public  static AudioRecordUtil getInstance() {
        if (mInstance == null) {
            synchronized (AudioRecordUtil.class){
                if(mInstance==null){
                    mInstance = new AudioRecordUtil();
                }
            }
        }
        return mInstance;
    }

    //读取录音数字数据线程
    class WriteThread implements Runnable {
        @Override
        public void run() {
            writeData();
        }
    }

    //录音线程执行体
    private void writeData() {
        noteArray = new byte[bufferSize];
        //建立文件输出流
        try {
            os = new BufferedOutputStream(new FileOutputStream(pcmFile));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        while (isRecording) {
            int recordSize = recorder.read(noteArray, 0, bufferSize);
            if (recordSize > 0) {
                try {
                    os.write(noteArray);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        if (os != null) {
            try {
                os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    //开始录音
    public void startRecord() {
        isRecording = true;
        recorder = new AudioRecord(audioSource, audioRate,
                audioChannel, audioFormat, bufferSize);
        recorder.startRecording();
    }

    //记录数据
    public void recordData() {
        new Thread(new WriteThread()).start();
    }

    //停止录音
    public void stopRecord() {
        if (recorder != null) {
            isRecording = false;
            recorder.stop();
            recorder.release();

        }
    }
}

/** Returns a new request body that transmits {@code content}. */
public static RequestBody create(final @Nullable MediaType contentType, final byte[] content) {
   return create(contentType, content, 0, content.length);
}

--this-is-a-boundary
Content-Disposition: form-data; name="metadata"
Content-Type: application/json; charset=UTF-8

{xxx这是一段json格式的数据xxx}

--this-is-a-boundary
Content-Disposition: form-data; name="audio"
Content-Type: application/octet-stream

pcm数据
--this-is-a-boundary--

@POST()
Flowable<ResponseBody> uploadPcm(@Url String url, @Body RequestBody body, @Header("xxx") String appId);

requestBody = RequestBody.create(MediaType.parse("*/*;charset=utf-8"), contentBytes, 0, contentBytes.length);
//contentBytes为服务端要求的requestBody对应的byte数组。

package com.ms.xiaoicestorydemo.util;

import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;

import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * pcm数据播放utils
 *
 * @anthor kb_jay
 * create at 2018/8/21 上午10:38
 */
public class AudioPlayUtils {

    private  final int BUFFER_SIZE = 1024 * 2;
    private  byte[] mBuffer = new byte[BUFFER_SIZE];
    private AudioPlayUtils() {
    }

    private static AudioPlayUtils instance;

    public static AudioPlayUtils getInstance() {
        if (instance == null) {
            synchronized (AudioPlayUtils.class) {
                if (instance == null) {
                    instance = new AudioPlayUtils();
                }
            }
        }
        return instance;
    }

    //播放pcm文件音频
    public void playPcmFileAudio(RandomAccessFile raf) {
        int streamType = AudioManager.STREAM_MUSIC;
        int simpleRate = 16000;
        int channelConfig = AudioFormat.CHANNEL_IN_DEFAULT;
        int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
        int mode = AudioTrack.MODE_STREAM;

        int minBufferSize = AudioTrack.getMinBufferSize(simpleRate, channelConfig, audioFormat);
        AudioTrack audioTrack = new AudioTrack(streamType, simpleRate, channelConfig, audioFormat,
                Math.max(minBufferSize, BUFFER_SIZE), mode);
        audioTrack.play();
        try {
            int read;
            while ((read = raf.read(mBuffer)) > 0) {
                audioTrack.write(mBuffer, 0, read);
            }
        } catch (RuntimeException | IOException e) {
            e.printStackTrace();
        }
    }
}

    public static final int DEFAULT = 0;
    /** 3GPP media file format*/
    public static final int THREE_GPP = 1;
    /** MPEG4 media file format*/
    public static final int MPEG_4 = 2;
    /** The following formats are audio only .aac or .amr formats */
    /**
     * AMR NB file format
     * @deprecated  Deprecated in favor of MediaRecorder.OutputFormat.AMR_NB
     */
    public static final int RAW_AMR = 3;
    /** AMR NB file format */
    public static final int AMR_NB = 3;
    /** AMR WB file format */
    public static final int AMR_WB = 4;
    /** @hide AAC ADIF file format */
    public static final int AAC_ADIF = 5;
    /** AAC ADTS file format */
    public static final int AAC_ADTS = 6;
    /** @hide Stream over a socket, limited to a single stream */
    public static final int OUTPUT_FORMAT_RTP_AVP = 7;
    /** H.264/AAC data encapsulated in MPEG2/TS */
    public static final int MPEG_2_TS = 8;
    /** VP8/VORBIS data in a WEBM container */
    public static final int WEBM = 9;
};

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.security.cert.Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class getApkSign {

    public static void main(String[] args) throws IOException {

        String path = "F:/myapk/test.apk";//apk的路径

        List<String> list = getSignaturesFromApk(path);
        // for (String s : list) {
        // System.out.println(s);
        // }
        System.out.println(list.get(0));
    }

    /**
     * 从APK中读取签名
     * 
     * @param file
     * @return
     * @throws IOException
     */
    private static List<String> getSignaturesFromApk(String strFile)
            throws IOException {
        File file = new File(strFile);
        List<String> signatures = new ArrayList<String>();
        JarFile jarFile = new JarFile(file);
        try {
            JarEntry je = jarFile.getJarEntry("AndroidManifest.xml");
            byte[] readBuffer = new byte[8192];
            Certificate[] certs = loadCertificates(jarFile, je, readBuffer);
            if (certs != null) {
                for (Certificate c : certs) {
                    String sig = toCharsString(c.getEncoded());
                    signatures.add(sig);
                }
            }
        } catch (Exception ex) {
        }
        return signatures;
    }

    /**
     * 加载签名
     * 
     * @param jarFile
     * @param je
     * @param readBuffer
     * @return
     */
    private static Certificate[] loadCertificates(JarFile jarFile, JarEntry je,
            byte[] readBuffer) {
        try {
            InputStream is = jarFile.getInputStream(je);
            while (is.read(readBuffer, 0, readBuffer.length) != -1) {
            }
            is.close();
            return je != null ? je.getCertificates() : null;
        } catch (IOException e) {
        }
        return null;
    }

    /**
     * 将签名转成转成可见字符串
     * 
     * @param sigBytes
     * @return
     */
    private static String toCharsString(byte[] sigBytes) {
        byte[] sig = sigBytes;
        final int N = sig.length;
        final int N2 = N * 2;
        char[] text = new char[N2];
        for (int j = 0; j < N; j++) {
            byte v = sig[j];
            int d = (v >> 4) & 0xf;
            text[j * 2] = (char) (d >= 10 ? ('a' + d - 10) : ('0' + d));
            d = v & 0xf;
            text[j * 2 + 1] = (char) (d >= 10 ? ('a' + d - 10) : ('0' + d));
        }
        return new String(text);
    }

}