Spring(SpringBoot)--将组件注入到静态工具类--方法/实例

野性酷女 2023-09-29 11:36 6阅读 0赞

原文网址：[Spring(SpringBoot)--将组件注入到静态工具类--方法/实例\_IT利刃出鞘的博客-CSDN博客][Spring_SpringBoot_--_--_IT_-CSDN]

## 简介 ##

**说明**

本文用示例介绍Spring如何将组件注入到静态工具类。

**需求**

在Controller层想使用一个静态工具，这个静态工具要使用其他组件。

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## 错误方法：在静态字段上注入 ##

**Controller**

package com.example.controller;
    
    import com.example.component.WelcomeUtil;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class HelloController {
        @GetMapping("/test")
        public String test() {
            WelcomeUtil.welcome();
            return "test success";
        }
    }

**工具类**

package com.example.component;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    @Component
    public class WelcomeUtil {
        @Autowired
        private static Hello hello;
    
        public static void welcome() {
            hello.sayHello();
        }
    }

**引入的组件**

package com.example.component;
    
    import org.springframework.stereotype.Component;
    
    @Component
    public class Hello {
        public void sayHello() {
            System.out.println("Hello");
        }
    }

**测试**

访问：[http://localhost:8080/test][http_localhost_8080_test]

![ffbea737668f4a218625f596b2bf6741.png][]

后端结果

![dfd8091fb72b45f8bff781ecd8bf991f.png][]

## 方案1：构造器注入 ##

其余代码与上边相同

**工具类**

package com.example.component;
    
    import org.springframework.stereotype.Component;
    
    @Component
    public class WelcomeUtil {
        private static Hello hello;
    
        public WelcomeUtil(Hello hello) {
            WelcomeUtil.hello = hello;
        }
    
        public static void welcome() {
            hello.sayHello();
        }
    }

**测试**

访问：[http://localhost:8080/test][http_localhost_8080_test]

![05c81987ae64499393ec12e2dc03936a.png][]

后端结果

![a8c4cdd33aaa42a498f723d7d17e31a9.png][]

## 方案2：setter注入 ##

其余代码与上边相同

**工具类**

package com.example.component;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    @Component
    public class WelcomeUtil {
        private static Hello hello;
    
        public static void welcome() {
            hello.sayHello();
        }
    
        @Autowired
        public void setHello(Hello hello) {
            WelcomeUtil.hello = hello;
        }
    }

**测试**

访问：[http://localhost:8080/test][http_localhost_8080_test]

结果

![3a87feb0bd324e42bfd94abde2c2ddd7.png][]

后端结果

![0de58913ccd14d2b88227ae0aceece6a.png][]

## 方案3：ApplicationContext工具类 ##

**ApplicationContext工具类**

package com.example.util;
    
    import org.springframework.beans.BeansException;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.ApplicationContextAware;
    import org.springframework.stereotype.Component;
     
    @Component
    public class ApplicationContextHolder implements ApplicationContextAware {
        private static ApplicationContext context;
     
        @Override
        public void setApplicationContext(ApplicationContext context) throws BeansException {
            ApplicationContextHolder.context = context;
        }
     
        public static ApplicationContext getContext() {
            return context;
        }
    }

**工具类**

package com.example.component;
    
    import com.example.util.ApplicationContextHolder;
    import org.springframework.stereotype.Component;
    
    @Component
    public class WelcomeUtil {
        public static void welcome() {
            ApplicationContextHolder.getContext()
                    .getBean(Hello.class).sayHello();
    
        }
    }

**测试**

访问：[http://localhost:8080/test][http_localhost_8080_test]

结果

![bb0374941dfb42768d764f1d307af999.png][]

后端结果

![b0bb42891e564bd0803aff1a23f412a9.png][]

[Spring_SpringBoot_--_--_IT_-CSDN]: https://knife.blog.csdn.net/article/details/124359305
[Link 1]: https://app.yinxiang.com/fx/d2ac6ff4-94c5-4e5f-9d4f-f5dfc344ede6
[http_localhost_8080_test]: http://localhost:8080/test
[ffbea737668f4a218625f596b2bf6741.png]: https://img-blog.csdnimg.cn/ffbea737668f4a218625f596b2bf6741.png
[dfd8091fb72b45f8bff781ecd8bf991f.png]: https://img-blog.csdnimg.cn/dfd8091fb72b45f8bff781ecd8bf991f.png
[05c81987ae64499393ec12e2dc03936a.png]: https://img-blog.csdnimg.cn/05c81987ae64499393ec12e2dc03936a.png
[a8c4cdd33aaa42a498f723d7d17e31a9.png]: https://img-blog.csdnimg.cn/a8c4cdd33aaa42a498f723d7d17e31a9.png
[3a87feb0bd324e42bfd94abde2c2ddd7.png]: https://img-blog.csdnimg.cn/3a87feb0bd324e42bfd94abde2c2ddd7.png
[0de58913ccd14d2b88227ae0aceece6a.png]: https://img-blog.csdnimg.cn/0de58913ccd14d2b88227ae0aceece6a.png
[bb0374941dfb42768d764f1d307af999.png]: https://img-blog.csdnimg.cn/bb0374941dfb42768d764f1d307af999.png
[b0bb42891e564bd0803aff1a23f412a9.png]: https://img-blog.csdnimg.cn/b0bb42891e564bd0803aff1a23f412a9.png