问题

我已经开始学习OpenCV Java，并且这是我编写的用于测试OpenCV设置的程序：

```java
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
public class FirstProgram 
{
    public static void main(String args[]) 
    {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
        System.out.println(mat.dump());
    }
}

但是运行这个程序时，Eclipse显示错误：
"错误：找不到或加载主类FirstProgram
原因：java.lang.ClassNotFoundException: FirstProgram*"

我已经设置了user libraries，并将库添加到project folder中。（链接到屏幕截图）

我应该如何解决这个问题？

• OpenCV版本：4.2.0
• Eclipse：2019-03
• JDK：13

<details>
<summary>英文:</summary>

I have started learning OpenCV Java and this is the program I have written to test the OpenCV setup:

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
public class FirstProgram
{
public static void main(String args[])
{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
System.out.println(mat.dump());
}
}

But on running this, Eclipse shows the error: 
"*Error: Could not find or load main class FirstProgram
Caused by: java.lang.ClassNotFoundException: FirstProgram*"

I have already setup the [user libraries][1] and added the libraries to the [project folder][2]. (Screenshots linked)

How do I resolve this issue ?

- OpenCV version: 4.2.0 
- Eclipse: 2019-03 
- JDK: 13

  [1]: https://i.stack.imgur.com/TiwYu.jpg
  [2]: https://i.stack.imgur.com/kHTdg.jpg

</details>


# 答案1
**得分**: 1

Eclipse 2019-03（发布于2019年3月）对于Java 13（发布于2019年9月）来说过于陈旧。

请[升级][1]至当前版本（目前为Eclipse 2020-03）。

[1]: https://stackoverflow.com/a/46273081/6505250

<details>
<summary>英文:</summary>

Eclipse 2019-03 (released March 2019) is too old for Java 13 (released September 2019).

Please [upgrade][1] to the current version (currently, Eclipse 2020-03).


  [1]: https://stackoverflow.com/a/46273081/6505250

</details>