好的交互设计网站,工信部网站黑名单查询,为加强政协网站建设,开发微分销系统Spring常用组件注册注解开发案例 文章目录 Spring常用组件注册注解开发案例1. 组件注册注解1. Configuration2.Bean注解3. Configuration与Bean注解使用案例4. ComponentScan注解5. 自定义TypeFilter指定过滤规则 什么是spring注解开发#xff1f; 就是不再使用Spring的bean.x…Spring常用组件注册注解开发案例 文章目录 Spring常用组件注册注解开发案例1. 组件注册注解1. Configuration2.Bean注解3. Configuration与Bean注解使用案例4. ComponentScan注解5. 自定义TypeFilter指定过滤规则 什么是spring注解开发 就是不再使用Spring的bean.xml文件纯使用注解的方式开发; 要使用纯注解开发就需要有一个配置类配置类配置文件 spring版本 dependencygroupIdorg.springframework/groupIdartifactIdspring-context/artifactIdversion5.1.5.RELEASE/version
/dependency1. 组件注册注解
1. Configuration
Configuration:一旦在某个类上标注了此注解说明此类就是一个配置类
注解的定义如下
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.springframework.context.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.springframework.core.annotation.AliasFor;
import org.springframework.stereotype.Component;Target({ElementType.TYPE})
Retention(RetentionPolicy.RUNTIME)
Documented
Component
public interface Configuration {AliasFor(annotation Component.class)String value() default ;
}2.Bean注解
Bean:给容器中注册一个bean;类型为返回值的类型,id默认使用方法名作为id
注解的定义如下
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//package org.springframework.context.annotation;import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.core.annotation.AliasFor;Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
Retention(RetentionPolicy.RUNTIME)
Documented
public interface Bean {AliasFor(name)String[] value() default {};AliasFor(value)String[] name() default {};/** deprecated */DeprecatedAutowire autowire() default Autowire.NO;boolean autowireCandidate() default true;String initMethod() default ;String destroyMethod() default (inferred);
}3. Configuration与Bean注解使用案例
定义一个名为Person的类如下
package com.yuan.bean;public class Person {private String name;private Integer age;public Person() {}public Person(String name, Integer age) {this.name name;this.age age;}public String getName() {return name;}public void setName(String name) {this.name name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age age;}Overridepublic String toString() {return Person{ name name \ , age age };}
}传统的方式实现注册一个bean的方式 1.编写spring的核心配置文件如bean.xml ?xml version1.0 encodingUTF-8?
beans xmlnshttp://www.springframework.org/schema/beansxmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexmlns:contexthttp://www.springframework.org/schema/contextxsi:schemaLocationhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsd !--包扫描xml配置:只要标注了Controller、Service、Repository、Component等注解它们会自动的加载到IOC容器中--!--context:component-scan base-packagecom.yuan/context:component-scan--!--使用set方式赋值--bean idperson classcom.yuan.bean.Personproperty nameage value22 /property namename valuejinshengyuan//bean
/beans加载spring核心配置文件 bean.xml文件来初始化一个Person类 package com.yuan;import com.yuan.bean.Person;
import com.yuan.config.MainConfig;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class MainTest {public static void main(String[] args) {//xml配置的方式ApplicationContext applicationContext new ClassPathXmlApplicationContext(bean.xml);Person person (Person) applicationContext.getBean(person);System.out.println(person);}}
}
执行结果Person{namejinshengyuan, age22}使用注解驱动开发方式注册一个bean 编写一个配置类如下面的MainConfig.java package com.yuan.config;import com.yuan.bean.Person;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
//配置类 配置文件
Configuration //告诉spring这是一个配置类
public class MainConfig {/*** Bean注解 给容器中注册一个bean;类型为返回值的类型,id默认使用方法名作为id* 如果要自己指定id,则需要加上name属性,如bean(valueperson),value可省略写成Bean(person)* return*/Bean(name person)public Person person01(){return new Person(张三,20);}
}初始化bean package com.yuan;import com.yuan.bean.Person;
import com.yuan.config.MainConfig;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class MainTest {public static void main(String[] args) {//xml配置的方式/*ApplicationContext applicationContext new ClassPathXmlApplicationContext(bean.xml);Person person (Person) applicationContext.getBean(person);System.out.println(person);*///使用注解的方式为IOC容器注册一个组件ApplicationContext applicationContext new AnnotationConfigApplicationContext(MainConfig.class);Person person applicationContext.getBean(Person.class);System.out.println(person);//根据类型获取bean的名称String[] beanNamesForType applicationContext.getBeanNamesForType(Person.class);for (int i0;ibeanNamesForType.length;i){System.out.println(beanNamesForType[i]);}}
}4. ComponentScan注解 ComponentScan只要标注了Controller、Service、Repository、Component等注解它们会通过ComponentScan自动的加载到IOC容器中 ComponentScan属性
value指定自动扫描的包excludeFilters ComponentScan.Filter[] : 指定扫描的时候按照什么规则排除哪些组件;includeFilters ComponentScan.Filter[] : 指定扫描的时,只需要包含哪些组件,还需配合与禁用默认规则一起使用;useDefaultFilters false : 禁用自动扫描的默认规则
ComponentScan.Filter的属性
ComponentScan.Filter的属性type过滤规则FilterType.ANNOTATION按照注解(常用)FilterType.ASSIGNABLE_TYPE 按照给定的类型(常用)FilterType.ASPECTJ使用ASPECTJ表达式FilterType.CUSTOM 使用自定义规则FilterType.REGEX 使用正则表达式指定xml配置方法
context:component-scan base-packagecom.yuan/context:component-scan注解方式Java8
package com.yuan.config;import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;Configuration
ComponentScan(value com.yuan,excludeFilters {ComponentScan.Filter(type FilterType.ANNOTATION,classes {Controller.class})
},includeFilters {ComponentScan.Filter(type FilterType.ANNOTATION,classes {Service.class})ComponentScan.Filter(type FilterType.ASSIGNABLE_TYPE,classes {BookServices.class}
},useDefaultFilters false) //自动扫描的包//excludeFilters ComponentScan.Filter[] : 指定扫描的时候按照什么规则排除哪些组件
//includeFilters ComponentScan.Filter[] : 指定扫描的时,只需要包含哪些组件,还需配合禁用掉默认规则一起使用
//useDefaultFilters false : 禁用自动扫描的的默认规则
//如果是Java8版本则可以多次使用ComponentScan注解如果Java8之前的版本则使用ComponentScans注解来多次使用ComponentScan注解
ComponentScan(...) //java8中可以写多个ComponentScan
ComponentScan(...) //java8中可以写多个ComponentScan
public class MyConfigOne {Bean(person)public Person person(){return new Person(李四,25);}
}注解方式Java8以下版本要配置多个ComponentScan时使用ComponentScans注解来做
package com.yuan.config;import com.yuan.bean.Person;
import org.springframework.context.annotation.*;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;Configuration
ComponentScans(value {ComponentScan(value com.yuan, excludeFilters {ComponentScan.Filter(type FilterType.ANNOTATION, classes {Controller.class})}, includeFilters {ComponentScan.Filter(type FilterType.ANNOTATION, classes {Service.class})}, useDefaultFilters false) //自动扫描的包}
)
//excludeFilters ComponentScan.Filter[] : 指定扫描的时候按照什么规则排除哪些组件
//includeFilters ComponentScan.Filter[] : 指定扫描的时,只需要包含哪些组件,还需配合禁用掉默认规则一起使用
//useDefaultFilters false : 禁用自动扫描的的默认规则
//如果是Java8版本则可以多次使用ComponentScan注解如果Java8之前的版本则使用ComponentScans注解来多次使用ComponentScan注解
public class MyConfigOne {Bean(person)public Person person(){return new Person(李四,25);}
}5. 自定义TypeFilter指定过滤规则
编写自定义规则类
package com.yuan.config;import org.springframework.context.annotation.FilterType;
import org.springframework.core.io.Resource;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.core.type.ClassMetadata;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.core.type.filter.TypeFilter;import java.io.IOException;/*** ComponentScan.Filter 的type属性自定义规则类(type FilterType.CUSTOM)实现了TypeFilter接口*/
public class MyTypeFilter implements TypeFilter {/**** param metadataReader the metadata reader for the target class (读取到的正在扫描的类的信息)* param metadataReaderFactory a factory for obtaining metadata readers (是一个工厂,可以获取其他任何类的信息)* * for other classes (such as superclasses and interfaces)* return* throws IOException*/Overridepublic boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException {//获取当前类注解信息AnnotationMetadata annotationMetadata metadataReader.getAnnotationMetadata();//获取当前正在扫描的类的信息比它的类型式什么,实现了哪些接口等等ClassMetadata classMetadata metadataReader.getClassMetadata();//获取当前类的类名String className classMetadata.getClassName();System.out.println(---className----className);//获取当前类的资源信息(如类的路径)Resource resource metadataReader.getResource();//如果类名中包含er则匹配成功if(className.contains(er)){return true;}return false;}
}自定义规则配置类
package com.yuan.config;import com.yuan.bean.Person;
import org.springframework.context.annotation.*;Configuration
//如果Java8之前的版本则使用ComponentScans注解来多次使用ComponentScan注解
ComponentScans(value {ComponentScan(value com.yuan, includeFilters {ComponentScan.Filter(type FilterType.CUSTOM, classes {MyTypeFilter.class})}, useDefaultFilters false) //自动扫描的包}
)
/*ComponentScan.Filter过滤规则FilterType.ANNOTATION按照注解(常用)FilterType.ASSIGNABLE_TYPE 按照给定的类型(常用)FilterType.ASPECTJ使用ASPECTJ表达式FilterType.CUSTOM 使用自定义规则FilterType.REGEX 使用正则表达式指定*/
public class MyConfigTwo {Bean(value person)public Person person() {return new Person(张三, 33);}
}
测试
package com.yuan.test;import com.yuan.config.MainConfig;
import com.yuan.config.MyConfigTwo;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class IOCTest {Testpublic void testTwo(){AnnotationConfigApplicationContext applicationContext new AnnotationConfigApplicationContext(MyConfigTwo.class);String[] beanDefinitionNames applicationContext.getBeanDefinitionNames();for (String beanDefinitionName : beanDefinitionNames) {System.out.println(beanDefinitionName);}}
}
执行结果
---className----com.yuan.test.IOCTest
---className----com.yuan.MainTest
---className----com.yuan.bean.Person
---className----com.yuan.config.MainConfig
---className----com.yuan.config.MyConfigOne
---className----com.yuan.config.MyTypeFilter
---className----com.yuan.controller.BookController
---className----com.yuan.dao.BookDao
---className----com.yuan.services.BookServices
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactorymyConfigTwo ----配置类自己
person ----Bean加载的person类由容器创建的所有会看到
下面这三个就是由MyTypeFilter过滤规则进行过滤的类
myTypeFilter
bookController
bookServices
