/**
 * 问题：我想记录坦克的移动时间
 * 最简单的办法：修改代码，记录时间
 * 问题2：如果无法改变方法源码呢？
 * 用继承？
 * v05:使用代理
 * v06:代理有各种类型
 * 问题：如何实现代理的各种组合？继承？Decorator?
 * v07:代理的对象改成Movable类型-越来越像decorator了
 *
 */
public class Tank implements Movable {

    /**
     * 模拟坦克移动了一段儿时间
     */
    @Override
    public void move() {
        System.out.println("Tank moving claclacla...");
        try {
            Thread.sleep(new Random().nextInt(10000));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {

        Tank t = new Tank();
        TankTimeProxy ttp = new TankTimeProxy(t);
        TankLogProxy tlp = new TankLogProxy(ttp);
        tlp.move();

//        new TankLogProxy(
//                new TankTimeProxy(
//                        new Tank()
//                )
//        ).move();
    }
}

class TankTimeProxy implements Movable {
    Movable m;

    public TankTimeProxy(Movable m) {
        this.m = m;
    }

    @Override
    public void move() {
        long start = System.currentTimeMillis();
        m.move();
        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }
}

class TankLogProxy implements Movable {
    Movable m;

    public TankLogProxy(Movable m) {
        this.m = m;
    }

    @Override
    public void move() {
        System.out.println("start moving...");
        m.move();
        long end = System.currentTimeMillis();
        System.out.println("stopped!");
    }
}

interface Movable {
    void move();
}

/**
 * 问题：我想记录坦克的移动时间
 * 最简单的办法：修改代码，记录时间
 * 问题2：如果无法改变方法源码呢？
 * 用继承？
 * v05:使用代理
 * v06:代理有各种类型
 * 问题：如何实现代理的各种组合？继承？Decorator?
 * v07:代理的对象改成Movable类型-越来越像decorator了
 * v08:如果有stop方法需要代理...
 * 如果想让LogProxy可以重用，不仅可以代理Tank，还可以代理任何其他可以代理的类型
 * （毕竟日志记录，时间计算是很多方法都需要的东西），这时该怎么做呢？
 * 分离代理行为与被代理对象
 * 使用jdk的动态代理
 *
 * v09: 横切代码与业务逻辑代码分离 AOP
 * v10: 通过反射观察生成的代理对象
 * jdk反射生成代理必须面向接口，这是由Proxy的内部实现决定的
 */
public class Tank implements Movable {

    /**
     * 模拟坦克移动了一段儿时间
     */
    @Override
    public void move() {
        System.out.println("Tank moving claclacla...");
        try {
            Thread.sleep(new Random().nextInt(10000));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Tank tank = new Tank();

        System.getProperties().put("jdk.proxy.ProxyGenerator.saveGeneratedFiles","true");

        Movable m = (Movable)Proxy.newProxyInstance(Tank.class.getClassLoader(),
                new Class[]{Movable.class}, //tank.class.getInterfaces()
                new TimeProxy(tank)
        );

        m.move();

    }
}

class TimeProxy implements InvocationHandler {
    Movable m;

    public TimeProxy(Movable m) {
        this.m = m;
    }

    public void before() {
        System.out.println("method start..");
    }

    public void after() {
        System.out.println("method stop..");
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        //Arrays.stream(proxy.getClass().getMethods()).map(Method::getName).forEach(System.out::println);

        before();
        Object o = method.invoke(m, args);
        after();
        return o;
    }

}

interface Movable {
    void move();
}

public class Person {
    int id;
    String name;
    int age;
    double weight;
    int score;
    Location loc;

    private Person() {}

    public static class PersonBuilder {
        Person p = new Person();

        public PersonBuilder basicInfo(int id, String name, int age) {
            p.id = id;
            p.name = name;
            p.age = age;
            return this;
        }

        public PersonBuilder weight(double weight) {
            p.weight = weight;
            return this;
        }

        public PersonBuilder score(int score) {
            p.score = score;
            return this;
        }

        public PersonBuilder loc(String street, String roomNo) {
            p.loc = new Location(street, roomNo);
            return this;
        }

        public Person build() {
            return p;
        }
    }
  public static void main(String[] args) {
        Person p = new Person.PersonBuilder()
                .basicInfo(1, "zhangsan", 18)
                //.score(20)
                .weight(200)
                //.loc("bj", "23")
                .build();
    }
}

class Location {
    String street;
    String roomNo;

    public Location(String street, String roomNo) {
        this.street = street;
        this.roomNo = roomNo;
    }
}

// 1. `ctl`，可以看做一个int类型的数字，高3位表示线程池状态，低29位表示worker数量
private final AtomicInteger ctl = new AtomicInteger(ctlOf(RUNNING, 0));
// 2. `COUNT_BITS`，`Integer.SIZE`为32，所以`COUNT_BITS`为29
private static final int COUNT_BITS = Integer.SIZE - 3;
// 3. `CAPACITY`，线程池允许的最大线程数。1左移29位，然后减1，即为 2^29 - 1
private static final int CAPACITY   = (1 << COUNT_BITS) - 1;

// runState is stored in the high-order bits
// 4. 线程池有5种状态，按大小排序如下：RUNNING < SHUTDOWN < STOP < TIDYING < TERMINATED
private static final int RUNNING    = -1 << COUNT_BITS;
private static final int SHUTDOWN   =  0 << COUNT_BITS;
private static final int STOP       =  1 << COUNT_BITS;
private static final int TIDYING    =  2 << COUNT_BITS;
private static final int TERMINATED =  3 << COUNT_BITS;

// Packing and unpacking ctl
// 5. `runStateOf()`，获取线程池状态，通过按位与操作，低29位将全部变成0
private static int runStateOf(int c)     { return c & ~CAPACITY; }
// 6. `workerCountOf()`，获取线程池worker数量，通过按位与操作，高3位将全部变成0
private static int workerCountOf(int c)  { return c & CAPACITY; }
// 7. `ctlOf()`，根据线程池状态和线程池worker数量，生成ctl值
private static int ctlOf(int rs, int wc) { return rs | wc; }

/*
 * Bit field accessors that don't require unpacking ctl.
 * These depend on the bit layout and on workerCount being never negative.
 */
// 8. `runStateLessThan()`，线程池状态小于xx
private static boolean runStateLessThan(int c, int s) {
    return c < s;
}
// 9. `runStateAtLeast()`，线程池状态大于等于xx
private static boolean runStateAtLeast(int c, int s) {
    return c >= s;
}

public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue,
                          ThreadFactory threadFactory,
                          RejectedExecutionHandler handler) {
    // 基本类型参数校验
    if (corePoolSize < 0 ||
        maximumPoolSize <= 0 ||
        maximumPoolSize < corePoolSize ||
        keepAliveTime < 0)
        throw new IllegalArgumentException();
    // 空指针校验
    if (workQueue == null || threadFactory == null || handler == null)
        throw new NullPointerException();
    this.corePoolSize = corePoolSize;
    this.maximumPoolSize = maximumPoolSize;
    this.workQueue = workQueue;
    // 根据传入参数`unit`和`keepAliveTime`，将存活时间转换为纳秒存到变量`keepAliveTime `中
    this.keepAliveTime = unit.toNanos(keepAliveTime);
    this.threadFactory = threadFactory;
    this.handler = handler;
}

public void execute(Runnable command) {
    if (command == null)
        throw new NullPointerException();
    /*
     * Proceed in 3 steps:
     *
     * 1. If fewer than corePoolSize threads are running, try to
     * start a new thread with the given command as its first
     * task.  The call to addWorker atomically checks runState and
     * workerCount, and so prevents false alarms that would add
     * threads when it shouldn't, by returning false.
     *
     * 2. If a task can be successfully queued, then we still need
     * to double-check whether we should have added a thread
     * (because existing ones died since last checking) or that
     * the pool shut down since entry into this method. So we
     * recheck state and if necessary roll back the enqueuing if
     * stopped, or start a new thread if there are none.
     *
     * 3. If we cannot queue task, then we try to add a new
     * thread.  If it fails, we know we are shut down or saturated
     * and so reject the task.
     */
    int c = ctl.get();
    // worker数量比核心线程数小，直接创建worker执行任务
    if (workerCountOf(c) < corePoolSize) {
        if (addWorker(command, true))
            return;
        c = ctl.get();
    }
    // worker数量超过核心线程数，任务直接进入队列
    if (isRunning(c) && workQueue.offer(command)) {
        int recheck = ctl.get();
        // 线程池状态不是RUNNING状态，说明执行过shutdown命令，需要对新加入的任务执行reject()操作。
        // 这儿为什么需要recheck，是因为任务入队列前后，线程池的状态可能会发生变化。
        if (! isRunning(recheck) && remove(command))
            reject(command);
        // 这儿为什么需要判断0值，主要是在线程池构造方法中，核心线程数允许为0
        else if (workerCountOf(recheck) == 0)
            addWorker(null, false);
    }
    // 如果线程池不是运行状态，或者任务进入队列失败，则尝试创建worker执行任务。
    // 这儿有3点需要注意：
    // 1. 线程池不是运行状态时，addWorker内部会判断线程池状态
    // 2. addWorker第2个参数表示是否创建核心线程
    // 3. addWorker返回false，则说明任务执行失败，需要执行reject操作
    else if (!addWorker(command, false))
        reject(command);
}

private boolean addWorker(Runnable firstTask, boolean core) {
    retry:
    // 外层自旋
    for (;;) {
        int c = ctl.get();
        int rs = runStateOf(c);

        // 这个条件写得比较难懂，我对其进行了调整，和下面的条件等价
        // (rs > SHUTDOWN) ||
        // (rs == SHUTDOWN && firstTask != null) ||
        // (rs == SHUTDOWN && workQueue.isEmpty())
        // 1. 线程池状态大于SHUTDOWN时，直接返回false
        // 2. 线程池状态等于SHUTDOWN，且firstTask不为null，直接返回false
        // 3. 线程池状态等于SHUTDOWN，且队列为空，直接返回false
        // Check if queue empty only if necessary.
        if (rs >= SHUTDOWN &&
            ! (rs == SHUTDOWN &&
               firstTask == null &&
               ! workQueue.isEmpty()))
            return false;

        // 内层自旋
        for (;;) {
            int wc = workerCountOf(c);
            // worker数量超过容量，直接返回false
            if (wc >= CAPACITY ||
                wc >= (core ? corePoolSize : maximumPoolSize))
                return false;
            // 使用CAS的方式增加worker数量。
            // 若增加成功，则直接跳出外层循环进入到第二部分
            if (compareAndIncrementWorkerCount(c))
                break retry;
            c = ctl.get();  // Re-read ctl
            // 线程池状态发生变化，对外层循环进行自旋
            if (runStateOf(c) != rs)
                continue retry;
            // 其他情况，直接内层循环进行自旋即可
            // else CAS failed due to workerCount change; retry inner loop
        }
    }
    boolean workerStarted = false;
    boolean workerAdded = false;
    Worker w = null;
    try {
        w = new Worker(firstTask);
        final Thread t = w.thread;
        if (t != null) {
            final ReentrantLock mainLock = this.mainLock;
            // worker的添加必须是串行的，因此需要加锁
            mainLock.lock();
            try {
                // Recheck while holding lock.
                // Back out on ThreadFactory failure or if
                // shut down before lock acquired.
                // 这儿需要重新检查线程池状态
                int rs = runStateOf(ctl.get());

                if (rs < SHUTDOWN ||
                    (rs == SHUTDOWN && firstTask == null)) {
                    // worker已经调用过了start()方法，则不再创建worker
                    if (t.isAlive()) // precheck that t is startable
                        throw new IllegalThreadStateException();
                    // worker创建并添加到workers成功
                    workers.add(w);
                    // 更新`largestPoolSize`变量
                    int s = workers.size();
                    if (s > largestPoolSize)
                        largestPoolSize = s;
                    workerAdded = true;
                }
            } finally {
                mainLock.unlock();
            }
            // 启动worker线程
            if (workerAdded) {
                t.start();
                workerStarted = true;
            }
        }
    } finally {
        // worker线程启动失败，说明线程池状态发生了变化（关闭操作被执行），需要进行shutdown相关操作
        if (! workerStarted)
            addWorkerFailed(w);
    }
    return workerStarted;
}

private final class Worker
    extends AbstractQueuedSynchronizer
    implements Runnable
{
    /**
     * This class will never be serialized, but we provide a
     * serialVersionUID to suppress a javac warning.
     */
    private static final long serialVersionUID = 6138294804551838833L;

    /** Thread this worker is running in.  Null if factory fails. */
    final Thread thread;
    /** Initial task to run.  Possibly null. */
    Runnable firstTask;
    /** Per-thread task counter */
    volatile long completedTasks;

    /**
     * Creates with given first task and thread from ThreadFactory.
     * @param firstTask the first task (null if none)
     */
    Worker(Runnable firstTask) {
        setState(-1); // inhibit interrupts until runWorker
        this.firstTask = firstTask;
        // 这儿是Worker的关键所在，使用了线程工厂创建了一个线程。传入的参数为当前worker
        this.thread = getThreadFactory().newThread(this);
    }

    /** Delegates main run loop to outer runWorker  */
    public void run() {
        runWorker(this);
    }

    // 省略代码...
}

final void runWorker(Worker w) {
    Thread wt = Thread.currentThread();
    Runnable task = w.firstTask;
    w.firstTask = null;
    // 调用unlock()是为了让外部可以中断
    w.unlock(); // allow interrupts
    // 这个变量用于判断是否进入过自旋（while循环）
    boolean completedAbruptly = true;
    try {
        // 这儿是自旋
        // 1. 如果firstTask不为null，则执行firstTask；
        // 2. 如果firstTask为null，则调用getTask()从队列获取任务。
        // 3. 阻塞队列的特性就是：当队列为空时，当前线程会被阻塞等待
        while (task != null || (task = getTask()) != null) {
            // 这儿对worker进行加锁，是为了达到下面的目的
            // 1. 降低锁范围，提升性能
            // 2. 保证每个worker执行的任务是串行的
            w.lock();
            // If pool is stopping, ensure thread is interrupted;
            // if not, ensure thread is not interrupted.  This
            // requires a recheck in second case to deal with
            // shutdownNow race while clearing interrupt
            // 如果线程池正在停止，则对当前线程进行中断操作
            if ((runStateAtLeast(ctl.get(), STOP) ||
                 (Thread.interrupted() &&
                  runStateAtLeast(ctl.get(), STOP))) &&
                !wt.isInterrupted())
                wt.interrupt();
            // 执行任务，且在执行前后通过`beforeExecute()`和`afterExecute()`来扩展其功能。
            // 这两个方法在当前类里面为空实现。
            try {
                beforeExecute(wt, task);
                Throwable thrown = null;
                try {
                    task.run();
                } catch (RuntimeException x) {
                    thrown = x; throw x;
                } catch (Error x) {
                    thrown = x; throw x;
                } catch (Throwable x) {
                    thrown = x; throw new Error(x);
                } finally {
                    afterExecute(task, thrown);
                }
            } finally {
                // 帮助gc
                task = null;
                // 已完成任务数加一
                w.completedTasks++;
                w.unlock();
            }
        }
        completedAbruptly = false;
    } finally {
        // 自旋操作被退出，说明线程池正在结束
        processWorkerExit(w, completedAbruptly);
    }
}

public class OuterClass {
    private String name ;
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    class InnerClass{
        public InnerClass(){
            name = "chenssy";
            age = 23;
        }
    }
}

public interface Father {

}

public interface Mother {

}

public class Son implements Father, Mother {

}

public class Daughter implements Father{

    class Mother_ implements Mother{

    }
}

public class OuterClass {
    private String name ;
    private int age;

    /**省略getter和setter方法**/

    public class InnerClass{
        public InnerClass(){
            name = "chenssy";
            age = 23;
        }

        public void display(){
            System.out.println("name：" + getName() +"   ;age：" + getAge());
        }
    }

    public static void main(String[] args) {
        OuterClass outerClass = new OuterClass();
        OuterClass.InnerClass innerClass = outerClass.new InnerClass();
        innerClass.display();
    }
}
--------------
Output：
name：chenssy   ;age：23

public class OuterClass {
    public void display(){
        System.out.println("OuterClass...");
    }

    public class InnerClass{
        public OuterClass getOuterClass(){
            return OuterClass.this;
        }
    }

    public static void main(String[] args) {
        OuterClass outerClass = new OuterClass();
        OuterClass.InnerClass innerClass = outerClass.new InnerClass();
        innerClass.getOuterClass().display();
    }
}
-------------
Output:
OuterClass...

public class OuterClass {
    private String str;

    public void outerDisplay(){
        System.out.println("outerClass...");
    }

    public class InnerClass{
        public void innerDisplay(){
            //使用外围内的属性
            str = "chenssy...";
            System.out.println(str);
            //使用外围内的方法
            outerDisplay();
        }
    }

    /*推荐使用getxxx()来获取成员内部类，尤其是该内部类的构造函数无参数时 */
    public InnerClass getInnerClass(){
        return new InnerClass();
    }

    public static void main(String[] args) {
        OuterClass outer = new OuterClass();
        OuterClass.InnerClass inner = outer.getInnerClass();
        inner.innerDisplay();
    }
}
--------------------
chenssy...
outerClass...

public class Parcel5 {
    public Destionation destionation(String str){
        class PDestionation implements Destionation{
            private String label;
            private PDestionation(String whereTo){
                label = whereTo;
            }
            public String readLabel(){
                return label;
            }
        }
        return new PDestionation(str);
    }

    public static void main(String[] args) {
        Parcel5 parcel5 = new Parcel5();
        Destionation d = parcel5.destionation("chenssy");
    }
}

public class Parcel6 {
    private void internalTracking(boolean b){
        if(b){
            class TrackingSlip{
                private String id;
                TrackingSlip(String s) {
                    id = s;
                }
                String getSlip(){
                    return id;
                }
            }
            TrackingSlip ts = new TrackingSlip("chenssy");
            String string = ts.getSlip();
        }
    }

    public void track(){
        internalTracking(true);
    }

    public static void main(String[] args) {
        Parcel6 parcel6 = new Parcel6();
        parcel6.track();
    }
}

button2.addActionListener(  
                new ActionListener(){  
                    public void actionPerformed(ActionEvent e) {  
                        System.out.println("你按了按钮二");  
                    }  
                });

public class OuterClass {
    public InnerClass getInnerClass(final int num,String str2){
        return new InnerClass(){
            int number = num + 3;
            public int getNumber(){
                return number;
            }
        };        /* 注意：分号不能省 */
    }

    public static void main(String[] args) {
        OuterClass out = new OuterClass();
        InnerClass inner = out.getInnerClass(2, "chenssy");
        System.out.println(inner.getNumber());
    }
}

interface InnerClass {
    int getNumber();
}

----------------
Output:
5

public class OuterClass {
    private String sex;
    public static String name = "chenssy";

    /**
     *静态内部类
     */
    static class InnerClass1{
        /* 在静态内部类中可以存在静态成员 */
        public static String _name1 = "chenssy_static";

        public void display(){
            /*
             * 静态内部类只能访问外围类的静态成员变量和方法
             * 不能访问外围类的非静态成员变量和方法
             */
            System.out.println("OutClass name :" + name);
        }
    }

    /**
     * 非静态内部类
     */
    class InnerClass2{
        /* 非静态内部类中不能存在静态成员 */
        public String _name2 = "chenssy_inner";
        /* 非静态内部类中可以调用外围类的任何成员,不管是静态的还是非静态的 */
        public void display(){
            System.out.println("OuterClass name：" + name);
        }
    }

    /**
     * @desc 外围类方法
     * @author chenssy
     * @data 2013-10-25
     * @return void
     */
    public void display(){
        /* 外围类访问静态内部类：内部类. */
        System.out.println(InnerClass1._name1);
        /* 静态内部类 可以直接创建实例不需要依赖于外围类 */
        new InnerClass1().display();

        /* 非静态内部的创建需要依赖于外围类 */
        OuterClass.InnerClass2 inner2 = new OuterClass().new InnerClass2();
        /* 方位非静态内部类的成员需要使用非静态内部类的实例 */
        System.out.println(inner2._name2);
        inner2.display();
    }

    public static void main(String[] args) {
        OuterClass outer = new OuterClass();
        outer.display();
    }
}
----------------
Output:
chenssy_static
OutClass name :chenssy
chenssy_inner
OuterClass name：chenssy