java - Java中如何通过线程向ArrayList添加项目

Question

我想生成客户对象并将它们存储在 ArrayList 中，但我不能。

这是我的客户类别

public class Customer {
private int customerID;
private int processTime;

ArrayList<Integer> customerIDList = new ArrayList<>();
ArrayList<Integer> processTimeList = new ArrayList<>();

public int getCustomerID() {
    return customerID;
}

public void setCustomerID(int customerID) {
    this.customerID = customerID;
}

public int getProcessTime() {
    return processTime;
}

public void setProcessTime(int processTime) {
    this.processTime = processTime;
}

public ArrayList<Integer> getCustomerIDList() {
    return customerIDList;
}

public void setCustomerIDList(ArrayList<Integer> customerIDList) {
    this.customerIDList = customerIDList;
}

public ArrayList<Integer> getProcessTimeList() {
    return processTimeList;
}

public void setProcessTimeList(ArrayList<Integer> processTimeList) {
    this.processTimeList = processTimeList;
} 
}

CustomerThread 类，生成客户对象 10 次，两个客户之间的间隔为 100 毫秒

public class CustomerThread extends Thread {
Customer c = new Customer();
Methods method = new Methods();

@Override
public void run() {

    for(int i = 1; i <= 10; i++) {
        try {
            //c.setCustomerID(i); 
            //c.setProcessTime(method.generateProcessTime());

            c.getCustomerIDList().add(i);
            c.getProcessTimeList().add(method.generateProcessTime());

            System.out.println("ID  : " + c.getCustomerIDList().get(i) + " - Process Time : " + c.getProcessTimeList().get(i));
            Thread.sleep(100);   
        }
        catch (InterruptedException ex) {
            Logger.getLogger(CustomerThread.class.getName()).log(Level.SEVERE, null, ex);
        }
    }   
} 
}

generateProcessTime方法是生成随机int数，没有问题。这是我的测试类

public class Test {
public static void main(String[] args) {

    CustomerThread ct = new CustomerThread();

    ct.start();

}
}

当我执行这些时，会发生此错误，

Exception in thread "Thread-0" java.lang.IndexOutOfBoundsException: Index: 1, Size: 1

Answer 1

您正在将数字 1..10 添加到列表中

c.getCustomerIDList().add(i);

但随后您尝试检索索引 1..10 处的数字

c.getCustomerIDList().get(i)

但是列表是从 0 开始索引的，这就是为什么你会得到 IndexOutOfBoundsException
您应该从 0..9 迭代并添加值 i + 1:

for(int i = 0; i < 10; i++) {
  ...
  c.getCustomerIDList().add(i + 1);
  ...