public class CyclicBarrierDemo {
    static CyclicBarrier c = new CyclicBarrier(2);
    public static void main(String[] args) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        c.await();
                    } catch (InterruptedException | BrokenBarrierException e) {
                        e.printStackTrace();
                    }
                    //在子線程輸出1
                    System.out.println("1");
                }
            }).start();
        try {
            c.await();
            //在主線程輸出2
            System.out.println("2");
        } catch (InterruptedException | BrokenBarrierException e) {
            e.printStackTrace();
        }
    }
}

public class CyclicBarrierDemo {
    //實(shí)例化CyclicBarrier，并指定回調(diào)函數(shù)
    static CyclicBarrier c = new CyclicBarrier(2,new TestRunable());
    public static void main(String[] args) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        c.await();
                    } catch (InterruptedException | BrokenBarrierException e) {
                        e.printStackTrace();
                    }
                    System.out.println("1");
                }
            }).start();
        try {
            c.await();
            System.out.println("2");
        } catch (InterruptedException | BrokenBarrierException e) {
            e.printStackTrace();
        }
    }
    static class TestRunable implements Runnable{
        @Override
        public void run() {
            System.out.println("3");
        }
    }
}

public class UserConsumeInfo {
    private String userName;
    private List<UserAggreInfo> userAggreInfos;
    //省略必要的get set 方法......
}

public class UserAggreInfo {
    //年份
    private Integer year;
    //消費(fèi)金額
    private Integer amount;

    public UserAggreInfo(Integer year, Integer amount) {
        this.year = year;
        this.amount = amount;
    }
    //省略必要的get set 方法......
}    

public class CyclicBarrierTest {
    private CyclicBarrier cyclicBarrier;
    //保存客戶消費(fèi)數(shù)據(jù)
    private List<UserConsumeInfo> partialResults = new CopyOnWriteArrayList<>();
    private Random random = new Random();
    //要統(tǒng)計(jì)的年份
    private List<Integer> years;
    //統(tǒng)計(jì)的用戶
    private List<String> users;
    /**
     * 構(gòu)造函數(shù)
     * @param years
     * @param users
     */
    public CyclicBarrierTest(List<Integer> years, List<String> users) {
        this.years = years;
        this.users = users;
    }
    /**
     * 開(kāi)始計(jì)算用戶消費(fèi)信息
     */
    public void startCalc(){
        cyclicBarrier = new CyclicBarrier(users.size(), new AggregatorThread());
        for (int i = 0; i < users.size(); i++) {
            Thread worker = new Thread(new CalcUserAmountThread(users.get(i)));
            //把用戶設(shè)置為當(dāng)前線程名稱
            worker.setName(users.get(i));
            worker.start();
        }
    }
    /**
     * 計(jì)算用戶消費(fèi)金額線程
     */
    final class CalcUserAmountThread implements Runnable{
        //用戶名
        private String userName;
        public CalcUserAmountThread(String userName) {
            this.userName = userName;
        }
        @Override
        public void run() {
            UserConsumeInfo userConsumeInfo=new UserConsumeInfo();
            userConsumeInfo.setUserName(userName);
            //計(jì)算每年的消費(fèi)金額
            List<UserAggreInfo> userAggreInfos=new ArrayList<>();
            for (int i = 0; i < years.size(); i++) {
                Integer num = random.nextInt(1000);
                System.out.println("用戶："+userName+" "+years.get(i)+"年，消費(fèi)："+num+"元");
                userAggreInfos.add(new UserAggreInfo(years.get(i),num));
            }
            userConsumeInfo.setUserAggreInfos(userAggreInfos);
            partialResults.add(userConsumeInfo);
            try {
                System.out.println("用戶:"+userName + "到達(dá)barrier，等待其他用戶.");
                cyclicBarrier.await();
            } catch (InterruptedException | BrokenBarrierException e) {
            }
        }
    }
    /**
     * 聚合線程，算出用戶總的消費(fèi)金額
     */
    class AggregatorThread implements Runnable {
        @Override
        public void run() {
            System.out.println("=====統(tǒng)計(jì)用戶消費(fèi)信息=======");
            int sum = 0;//所有用戶消費(fèi)金額
            for (UserConsumeInfo user : partialResults) {
                String userName = user.getUserName();
                System.out.println("用戶："+userName+"消費(fèi)信息如下：");
                for (UserAggreInfo aggre : user.getUserAggreInfos()) {
                    System.out.print("\t"+aggre.getYear()+"年，"+"消費(fèi)"+aggre.getAmount()+"元"+"\t");
                    sum+=aggre.getAmount();
                }
                System.out.println();
            }
            System.out.println("所有用戶消費(fèi)總金額："+sum);
        }
    }
}

public static void main(String[] args) {
        List<String> userResults=new ArrayList<>();
        userResults.add("張三");
        userResults.add("李四");
        userResults.add("王二");
        userResults.add("小米");
        userResults.add("小明");
        userResults.add("小紅");
        userResults.add("小張");
        List<Integer> yearResults=new ArrayList<>();
        yearResults.add(2018);
        yearResults.add(2019);
        yearResults.add(2020);
        CyclicBarrierTest demo = new CyclicBarrierTest(yearResults,userResults);
        demo.startCalc();
    }