一个庙里， 三个和尚，只有一个碗， 三个和尚都要吃饭，所以每次吃饭的时候， 三个和尚抢着碗吃。

package interview.java.difference.l05;public class WaitAndNotifyAndNotifyAll {    static class Bowl{        private String id;        public String getId() {            return id;        }        public void setId(String id) {            this.id = id;        }            }        static class Monk1Eat implements Runnable{        private Bowl bowl;        private String name;                public Monk1Eat(Bowl bowl){            this.bowl=bowl;            name="monk1";        }                public String getName() {            return name;        }        public void run() {            while(true){                System.out.println(this.getName()+" is eating with bowl"+bowl.getId());            }                }            }        static class Monk2Eat implements Runnable{        private Bowl bowl;        private String name;                public Monk2Eat(Bowl bowl){            this.bowl=bowl;            name="monk2";        }                public String getName() {            return name;        }        public void run() {            while(true){                System.out.println(this.getName()+" is eating with bowl"+bowl.getId());            }                }            }        static class Monk3Eat implements Runnable{        private Bowl bowl;        private String name;                public Monk3Eat(Bowl bowl){            this.bowl=bowl;            name="monk3";        }                public String getName() {            return name;        }        public void run() {            while(true){                System.out.println(this.getName()+" is eating with bowl"+bowl.getId());            }                }            }        public static void main(String[] args) {        Bowl bowl = new Bowl();        bowl.setId("onlyOneBowl");        Thread monk1=new Thread(new Monk1Eat(bowl));        Thread monk2=new Thread(new Monk2Eat(bowl));        Thread monk3=new Thread(new Monk3Eat(bowl));        monk1.start();        monk2.start();        monk3.start();            }}

 

之后 三个和尚懂得互相谦让了。 每个人吃5分钟，换另一个人吃，随机换，这时候，停下吃的那个和尚等待，并把碗给另一个人。注意，是锁wait，然后锁notify另一个人。不是和尚wait然后notify，这样会报出illegalmonitorstate的异常。

 

package interview.java.difference.l05;public class WaitAndNotifyAndNotifyAll {    static class Bowl{        private String id;        public String getId() {            return id;        }        public void setId(String id) {            this.id = id;        }            }        static class Monk1Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk1Eat(Bowl bowl){            this.bowl=bowl;            name="monk1";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                while(true){                        try {                            bowl.wait(3*1000);                            bowl.notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        static class Monk2Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk2Eat(Bowl bowl){            this.bowl=bowl;            name="monk2";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                while(true){                        try {                            bowl.wait(3*1000);                            bowl.notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        static class Monk3Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk3Eat(Bowl bowl){            this.bowl=bowl;            name="monk3";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                long now=System.currentTimeMillis();                while(true){                        try {                            bowl.wait(3*1000);                            bowl.notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        public static void main(String[] args) {        Bowl bowl = new Bowl();        bowl.setId("onlyOneBowl");        Thread monk1=new Thread(new Monk1Eat(bowl));        Thread monk2=new Thread(new Monk2Eat(bowl));        Thread monk3=new Thread(new Monk3Eat(bowl));        monk1.start();        monk2.start();        monk3.start();            }}

 

 

使用线程去notify 和wait

代码：

package interview.java.difference.l05;public class WaitAndNotifyAndNotifyAll {    static class Bowl{        private String id;        public String getId() {            return id;        }        public void setId(String id) {            this.id = id;        }            }        static class Monk1Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk1Eat(Bowl bowl){            this.bowl=bowl;            name="monk1";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                while(true){                        try {                            Thread.currentThread().wait(3*1000);                            Thread.currentThread().notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        static class Monk2Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk2Eat(Bowl bowl){            this.bowl=bowl;            name="monk2";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                while(true){                        try {                            Thread.currentThread().wait(3*1000);                            Thread.currentThread().notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        static class Monk3Eat implements Runnable{        private Bowl bowl;        private String name;        private long now;                public Monk3Eat(Bowl bowl){            this.bowl=bowl;            name="monk3";            now=System.currentTimeMillis();        }                public String getName() {            return name;        }        public void run() {            synchronized (bowl) {                long now=System.currentTimeMillis();                while(true){                        try {                            Thread.currentThread().wait(3*1000);                            Thread.currentThread().notify();                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    System.out.println(this.getName()+" is eating with bowl"+bowl.getId());                    try {                        System.out.println(this.getName()+" is digesting");                        Thread.sleep(1000);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                }                        }            }        public static void main(String[] args) {        Bowl bowl = new Bowl();        bowl.setId("onlyOneBowl");        Thread monk1=new Thread(new Monk1Eat(bowl));        Thread monk2=new Thread(new Monk2Eat(bowl));        Thread monk3=new Thread(new Monk3Eat(bowl));        monk1.start();        monk2.start();        monk3.start();            }}

报错：

Exception in thread "Thread-0" Exception in thread "Thread-2" Exception in thread "Thread-1" java.lang.IllegalMonitorStateException    at java.lang.Object.wait(Native Method)    at interview.java.difference.l05.WaitAndNotifyAndNotifyAll$Monk1Eat.run(WaitAndNotifyAndNotifyAll.java:37)    at java.lang.Thread.run(Unknown Source)java.lang.IllegalMonitorStateException    at java.lang.Object.wait(Native Method)    at interview.java.difference.l05.WaitAndNotifyAndNotifyAll$Monk2Eat.run(WaitAndNotifyAndNotifyAll.java:76)    at java.lang.Thread.run(Unknown Source)java.lang.IllegalMonitorStateException    at java.lang.Object.wait(Native Method)    at interview.java.difference.l05.WaitAndNotifyAndNotifyAll$Monk3Eat.run(WaitAndNotifyAndNotifyAll.java:116)    at java.lang.Thread.run(Unknown Source)