找不到默认构造函数;嵌套异常是使用Spring MVC的java.lang.NoSuchMethodException？ [英] No default constructor found; nested exception is java.lang.NoSuchMethodException with Spring MVC?

问题描述

我正在使用Spring MVC控制器项目。下面是我的控制器，我有一个声明的构造函数，我专门用于测试目的。

I am working with Spring MVC controller project. Below is my Controller and I have a constructor declared which I am specifically using for testing purpose.

@Controller
public class TestController {

    private static KeeperClient testClient = null;

    static {

    // some code here

    }

    /**
     * Added specifically for unit testing purpose.
     * 
     * @param testClient
     */
    public TestController(KeeperClient testClient) {
        TestController.testClient = testClient;
    }

    // some method here

}

每当我启动服务器时，我都会遇到异常 -

Whenever I am starting the server, I am getting below exception -

No default constructor found; nested exception is java.lang.NoSuchMethodException:

但如果我删除 TestController 构造函数然后它没有任何问题正常工作。我在这里做错了什么？

But if I remove TestController constructor then it works fine without any problem. What wrong I am doing here?

但是如果我添加这个默认构造函数然后它开始工作正常 -

But if I add this default constructor then it starts working fine -

    public TestController() {

    }

推荐答案

如果要创建自己的构造函数，则必须定义no-args或默认构造函数。

You must have to define no-args or default constructor if you are creating your own constructor.

您可以阅读为什么默认或不需要参数构造函数。

You can read why default or no argument constructor is required.

why-default-or-no-argument-constructor-java-class.html

这篇关于找不到默认构造函数;嵌套异常是使用Spring MVC的java.lang.NoSuchMethodException？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！