1. 写两个线程，其中一个线程打印1 ~ 52,另一个线程打印A ~ Z,打印顺序应该是12A34B56C ... 5152Z，完成代码实现。

(1) 打印数字线程源码

package com.threadtest.code;

public class PrintNumThread implements Runnable {

    private PrintSequence printSequence;

    public PrintNumThread(PrintSequence printSequence) {
        this.printSequence = printSequence;
    }

    @Override
    public void run() {
        int i = 0;
        while(true) {
            synchronized (printSequence) {
                if(i == 52) {
                    break;
                }
                if(!printSequence.isNum()) {
                    System.out.print(++i);
                    if(i % 2 == 0) {
                        printSequence.setNum(true);
                        printSequence.notify();
                    }
                } else {
                    try {
                        printSequence.wait();
                    } catch (InterruptedException e) {

                    }
                }
            }
        }
    }
}

(2) 打印字母源码

package com.threadtest.code;

public class PrintAlbumThread implements Runnable {

    private PrintSequence printSequence;

    public PrintAlbumThread(PrintSequence printSequence) {
        this.printSequence = printSequence;
    }


    @Override
    public void run() {
        char[] arr = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
        int i = 0;
        while (true) {
            if(i == 26) {
                break;
            }
            synchronized (printSequence) {
                if(printSequence.isNum()) {
                    System.out.print(arr[i]);
                    i++;
                    printSequence.setNum(false);
                    printSequence.notify();
                } else {
                    try {
                        printSequence.wait();
                    } catch (InterruptedException e) {

                    }
                }
            }
        }
    }
}

(3) 共享资源源码

package com.threadtest.code;

public class PrintSequence {

    private boolean isNum = false;

    public boolean isNum() {
        return isNum;
    }

    public void setNum(boolean num) {
        isNum = num;
    }
}

(4) 测试执行源码

package com.threadtest.code;

public class PrintTest {

    public static void main(String[] args) {
        PrintSequence printSequence = new PrintSequence();
        PrintAlbumThread printAlbumThread = new PrintAlbumThread(printSequence);
        PrintNumThread printNumThread = new PrintNumThread(printSequence);
        new Thread(printAlbumThread).start();
        new Thread(printNumThread).start();
    }
}