Spring 注解使用笔记(一)

代码库位置：

https://gitee.com/sleeber/nuts.spring.sample

https://github.com/HazelNutsWorkGroup/nuts.spring.sample.git

实验步骤：

• 步骤一
  加载Spring Java配置文件

    //Java配置文件加载
    ApplicationContext context = new AnnotationConfigApplicationContext(ModelConfig.class);

  Bean 定义

    @Configuration
    public class ModelConfig {
  
        @Bean("person")
        public Person getPerson() {
            return new Person();
        }
    }

  提示： 对应测试方法 testGetPersonBean

• 步骤二 包扫描路径

    @Configuration
    @ComponentScan("nuts.spring.annotation")
    public class ModelConfig {
  
        @Bean("person")
        public Person getPerson() {
            return new Person();
        }
    }

  提示： 对应测试方法 testGetBeanNames

• 步骤三 excludeFilters

    @Configuration
    @ComponentScan(value = "nuts.spring.annotation", excludeFilters = {
            @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {Controller.class, Configuration.class})
    })
    public class ExcludeConfiguration {
  
    }

  提示： 对应测试方法 testExcludeBeanNames

• 步骤四 includeFilters

    @Configuration
    @ComponentScan(value = "nuts.spring.annotation", includeFilters = {
            @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {Service.class})
    }, useDefaultFilters = false) //需要禁用默认引入规则
    public class IncludeConfiguration {
  
    }

  提示： 对应测试方法 testIncludeBeanNames

• 步骤五 自定义Filter类型

    @Configuration
    @ComponentScan(value = "nuts.spring.annotation", includeFilters = {
            @ComponentScan.Filter(type = FilterType.CUSTOM, classes = {
                    CustomerFilter.class
            })
    })
    public class CustomerConfiguration {
    }

  提示： 对应测试方法 testIncludeBeanNames

• 步骤六 Scope 指定单实例/多实例

    /**
     * Scope's parameter
     * singleton Single instance, created during container initialization
     * prototype multi instance, created only when getting examples
     */
    @Scope("prototype")
    @Bean
    public Person person() {
        System.out.println("Instance person...");
        return new Person();
    }

  提示： 对应测试方法 testInstanceScope

• 步骤七 Lazy 懒加载

    @Lazy
    @Bean
    public Person person() {
        System.out.println("Instance person...");
        return new Person();
    }

  提示： 对应测试方法 testInstanceLazy

• 步骤八 Conditional 按条件加载

    @Conditional(WindowsCondition.class)
    @Bean("windows")
    public Person getWindows() {
        System.out.println("Instance Windows...");
        return new Person();
    }
  
    @Conditional(LinuxCondition.class)
    @Bean("linux")
    public Person getLinux() {
        System.out.println("Instance Linux...");
        return new Person();
    }

  提示： 对应测试方法 testConditional

• 步骤九 Import 快速引入第三方组件

  @Configuration
  @Import(Group.class)
  public class ImportConfiguration {
  
    /**
     * ComponentScan
     * Bean
     * Import
     */
    @Bean
    public Person person() {
        System.out.println("Instance person...");
        return new Person();
    }
  }

  提示： 对应测试方法 testImportBean

• 步骤十 ImportSelector 方式引入第三方组件

    @Configuration
    @Import({Group.class, MyImportSelector.class, MyImportBeanDefinitionRegistrar.class})
    public class ImportConfiguration { }
  
    public class MyImportSelector implements ImportSelector {
        @Override
        public String[] selectImports(AnnotationMetadata importingClassMetadata) {
            return new String[]{"nuts.spring.annotation.model.Classic"};
        }
    }

  提示： 对应测试方法 testImportBean

注意事项

框架、组件	注意事项
@Configuration	配置类为了防止相关影响，建议只开启测试对应的配置类
「框架、组件」	「框架、组件」的引入/配置的注意事项。

提示：列出项目开发中引入其他框架或技术需要特别关注或配置的事项。