用线程模拟生产者消费者去栈中存取字符
加了同步锁 两个线程时 不报错 生产者消费者加倍时就报错了
栈
public class Stack {
private char[] cr = new char[5];
private int index = 0;
public void push(char c) {
cr[index] = c;
index++;
}
public char pop() {
System.out.println("下标的值 " + index);
index--;
char c = cr[index];
return c;
}
public boolean isEmpty() {
System.out.println("数组为空判断 " + (index == 0));
return index == 0;
}
public boolean isFull() {
return index == 5;
}
}
线程模拟生产者
public class Producer extends Thread {
private Stack stack;
public Producer(Stack stack) {
super();
this.stack = stack;
}
public void run() {
while (true) {
// 随机生成a~z的英文字符,97 +[0,26)
char c = (char) ('a' + new Random().nextInt(26));
synchronized (stack) {
if (stack.isFull()) {
try {
stack.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
stack.push(c);
System.out.println("压入字符" + c);
stack.notifyAll();
}
}
}
}
线程模拟消费者
public class Consumer extends Thread {
private Stack stack;
public Consumer(Stack stack) {
super();
this.stack = stack;
}
public void run() {
while (true) {
synchronized (stack) {
if (stack.isEmpty()) {
try {
// 在栈对象上等待 收到通知后醒来继续执行
stack.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
char c = stack.pop();
System.out.println("取出字符" + c);
stack.notifyAll();
}
}
}
}
测试类 for循环 i小于1时不报错 i大于1就会报错
public class TestStack {
/**
* @Title: main
* @Description: 描述这个方法的作用
* @param: @param args 参数说明
* @return: void 返回类型
* @throws
*/
public static void main(String[] args) {
Stack stack = new Stack();
for (int i = 0; i < 2; i++) {
Producer producer = new Producer(stack);
producer.start();
Consumer consumer = new Consumer(stack);
consumer.start();
}
}
}
错误信息
Exception in thread "Thread-3" Exception in thread "Thread-0" java.lang.ArrayIndexOutOfBoundsException: Index -1 out of bounds for length 5 at com.dapang.test.Stack.pop(Stack.java:31)
at com.dapang.test.Consumer.run(Consumer.java:39)
java.lang.ArrayIndexOutOfBoundsException: Index -1 out of bounds for length 5
at com.dapang.test.Stack.push(Stack.java:24)
at com.dapang.test.Producer.run(Producer.java:42)
两个consumer和两个producer。假设两个producer同时进入判断条件阻塞，一个comsumer消费了一条数据之后唤醒所有producer，那这两个producer都会跳出你的判断条件了，都执行push操作，造成你的stack溢出。
你这种实现线程的方式是有问题的，生产者，消费者模式要共享数据，线程的生成方式应该是实现Runnable接口，而不是继承Thread类，实现Runnable接口才能共享数据。
死锁了吧，stack stack =new stack（）放入for循环中