??? ?? ???? ??? ??? ???? ?? ? ??? ??? ?? ?? ???? ???? ?? ?? ???? ??? ?? ?? ???? ???. ??? ???? ??? ?? ??; ?? ???? ??? ?? ???? ??? ?? ?? ???? ??? ???.

(?? ????: Java ???? ????)

??? ??? ?? ?? ???? ??? ?? ? ??? ???? ????. ??? ??? ???? ?? ?? ? ?? ???? ???? ???.

??-?? ??? ? ??? ???? ???. ?, ??-?? ??? ?? ?? ???? ??? ???? ? ??? ????? ?? ???? ????? ?? ?? ???? ?? ?? ???? ????? ???. ?????. ??-?? ??? ??? ?? ??? ?? ??? ?? ????? ??? ??(??? ??)? ?? ???? ?? ?????.

?? ?:

public class ReadWriteLockDemo {
    public static void main(String[] args) {
        ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
        Book book = new Book();//創(chuàng)建一本書，可讀可寫

        //兩個(gè)寫手
        for (int i = 0; i < 2; i++) {
            int num = i;
            new Thread(()->{
                try {
                    readWriteLock.writeLock().lock();
                    System.out.println("寫手"+num+"在寫文章");
                    book.write(String.valueOf(num),UUID.randomUUID().toString().substring(0,5));
                }catch (Exception e){
                    e.printStackTrace();
                }finally {
                    readWriteLock.writeLock().unlock();
                }
            },String.valueOf(i)).start();
        }

        //6個(gè)讀者
        for (int i = 0; i < 6; i++) {
            int num = i;
            new Thread(()->{
                try {
                    readWriteLock.readLock().lock();
                    String word = book.read(String.valueOf(num % 2));
                    System.out.println("讀者"+num+"在閱讀文章..."+word);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    readWriteLock.readLock().unlock();
                }
            },String.valueOf(i)).start();
        }
    }
}
class Book{
    HashMap<String, String> map = new HashMap<>();
    public void write(String key,String val){
        map.put(key, val);
    }
    public String read(String key){
        String word = map.get(key);
        return word;
    }
}

?? ??:

"C:\Program Files\Java\jdk1.8.0_144\bin\java.exe" "-javaagent:F:\MyDir\IDEA\IDEA2018\IntelliJ IDEA 2018.2.4\lib\idea_rt.jar=54141:F:\MyDir\IDEA\IDEA2018\IntelliJ IDEA 2018.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_144\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_144\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_144\jre\lib\rt.jar;E:\idea_workplace\javaBase\target\classes"
寫手0在寫文章
寫手1在寫文章
讀者0在閱讀文章...6b021
讀者1在閱讀文章...220e4
讀者2在閱讀文章...6b021
讀者4在閱讀文章...6b021
讀者3在閱讀文章...220e4
讀者5在閱讀文章...220e4

Process finished with exit code 0

??-?? ??? ???

(??? ???? ?? ??: java ??? ????)

??-?? ??? ??? ?? ?? ??? ????? ??? ??? ?? ????. ???? ?? ? ?? ??, ?? ? ?? ?? ??, ??? ??, ??? ???? ??? ??? ???? ??? ????.

?? ?? ???? ???? ??? ?? ?? ????(?: ??? ????) ???? ???? ??-?? ??? ????? ???? ?????. ??? ????? ?? ???? ???? ?? ???? ?? ???? ?? ?? ???? ????? ????.

?? ?? ??? ?? ??? ??-?? ?? ??? ????(????? ? ???)? ?? ??? ??? ? ????. ?? ?? ??-?? ?? ??? ??? ?? ???? ????? ?????. ?? ?? ??? ??. ????? ?????? ???? ??-?? ?? ??? ??????? ???? ??? ?????.

? ??? ??-?? ???? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!