Java ArrayList 类型不是通用的；它不能用参数 <Integer> 参数化
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22059271/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
The type ArrayList is not generic; it cannot be parameterized with arguments <Integer>
提问by Ryel
I am trying to complete a JCF array list, and it compiled just fine 30 minutes ago, but now I am receiving the error "The type ArrayList is not generic; it cannot be parameterized with arguments ". I have tried a few things to figure it out, but I am at a loss. Here is the code:
我正在尝试完成一个 JCF 数组列表，它在 30 分钟前编译得很好，但现在我收到错误“ArrayList 类型不是通用的；它不能用参数参数化”。我已经尝试了一些事情来弄清楚，但我不知所措。这是代码：
import java.util.*;
/**
* Class to test the java.util.ArrayList class.
*/
public class Main
{
public static void main(String[] args)
{
Main myAppl = new Main();
}
public Main()
{
ArrayList<Integer> numbers = new ArrayList<Integer>();
//list creation
for (int i = 0; i < 10; i++)
numbers.add((int) (Math.random() * 100));
System.out.println("List of numbers:");
System.out.println(numbers);
Scanner in = new Scanner(System.in);
System.out.print("Please, enter an int value: ");
int x = in.nextInt();
if (numbers.contains(x))
System.out.println("Found!");
else
System.out.println("Not found!");
}
}
回答by Alex Suo
2 possibilities:
2 种可能性：
You are using some mysterious ArrayList from a 3rd party package rather than java.util.ArrayList; or
Your compiler settings is pre-1.5 or your effective JDK is pre-1.5 so generic wasn't available.
您正在使用来自 3rd 方包的一些神秘的 ArrayList 而不是 java.util.ArrayList；或者
您的编译器设置是 1.5 之前的，或者您的有效 JDK 是 1.5 之前的，因此通用不可用。
回答by Elliott Frisch
Assuming you're using (and targeting) a version greater then or equal to 1.5 then you must have a class named ArrayList that shadows the one you want; you should use
假设您正在使用（并定位）一个大于或等于 1.5 的版本，那么您必须有一个名为 ArrayList 的类来隐藏您想要的那个；你应该使用
// If your compiler settings are correct.
java.util.ArrayList<Integer> numbers = new java.util.ArrayList<Integer>();
回答by Abdul Rasheed Mohammed
Try changing your class name to a different one. i.e. other than ArrayList or main.
尝试将您的班级名称更改为不同的名称。即除了 ArrayList 或 main。
