Java多線程總結六：經典生產者消費者問題實現

這是個線程同步的經典例子，源代碼如下：

1. package demo.thread;
3. /**
4. *經典生產者與消費者問題：生產者不斷的往倉庫中存放產品，消費者從倉庫中消費產品。
5. *其中生產者和消費者都可以有若干個。倉庫容量有限，庫滿時不能存放，庫空時不能取產品
6. */
8. public class ProducersAndConsumers {
9. public static void main(String[] args) {
10. Storage storage = new Storage();
11. Thread consumer = new Thread(new Consumer(storage));
12. consumer.setName("消費者");
13. Thread producer = new Thread(new Producer(storage));
14. producer.setName("生產者");
15. consumer.start();
16. producer.start();
17. }
18. }
20. /**
21. * 消費者
22. */
23. class Consumer implements Runnable {
24. private Storage storage;
26. public Consumer(Storage storage) {
27. this.storage = storage;
28. }
30. @Override
31. public void run() {
32. storage.pop();
33. }
34. }
36. /**
37. * 生產者
38. */
39. class Producer implements Runnable {
40. private Storage storage;
42. public Producer(Storage storage) {
43. this.storage = storage;
44. }
46. @Override
47. public void run() {
48. Product product = new Product("090505105", "電話");
49. storage.push(product);
50. }
52. }
54. /**
55. * 產品類
56. */
57. class Product {
58. private String id;// 產品id
59. private String name;// 產品名稱
61. public Product(String id, String name) {
62. this.id = id;
63. this.name = name;
64. }
66. @Override
67. public String toString() {
68. return "(產品ID：" + id + " 產品名稱：" + name + ")";
69. }
71. public String getId() {
72. return id;
73. }
75. public void setId(String id) {
76. this.id = id;
77. }
79. public String getName() {
80. return name;
81. }
83. public void setName(String name) {
84. this.name = name;
85. }
87. }
89. /**
90. *倉庫
91. */
92. class Storage {
93. // 倉庫容量為10
94. private Product[] products = new Product[10];
95. private int top = 0;
97. // 生產者往倉庫中放入產品
98. public synchronized void push(Product product) {
99. while (top == products.length) {
100. try {
101. wait();//倉庫已滿，等待
102. } catch (InterruptedException e) {
103. // TODO Auto-generated catch block
104. e.printStackTrace();
105. }
106. }
107. //把產品放入倉庫
108. products[top++] = product;
109. System.out.println(Thread.currentThread().getName() + " 生產了產品"
110. + product);
111. notifyAll();//喚醒等待線程
113. }
115. // 消費者從倉庫中取出產品
116. public synchronized Product pop() {
117. while (top == 0) {
118. try {
119. wait();//倉庫空，等待
120. } catch (InterruptedException e) {
121. // TODO Auto-generated catch block
122. e.printStackTrace();
123. }
125. }
127. //從倉庫中取產品
128. --top;
129. Product p = new Product(products[top].getId(), products[top].getName());
130. products[top] = null;
131. System.out.println(Thread.currentThread().getName() + " 消費了產品" + p);
132. notifyAll();//喚醒等待線程
133. return p;
134. }
135. }

運行結果：

生產者 生產了產品(產品ID：090505105 產品名稱：電話)
消費者 消費了產品(產品ID：090505105 產品名稱：電話)