Spring 依赖注入

依赖注入方式:

1.构造器注入

2.setter注入

3.接口注入

maven   pom.xml配置

引入jar包和依赖jar

<packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.2.RELEASE</version>
        </dependency>
    </dependencies>

一定要保持版本一样，不然后面注解注入@Component会报错 

配置spring-cfg.xml

<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">
</beans>

1.构造器注入

public class Role {
    private Long id;
    private String roleName;
    private String note;

    public Role(){
    }

    public Role(Long id, String roleName, String note) {
        this.id = id;
        this.roleName = roleName;
        this.note = note;
    }

    public Long getId() {
        return id;
    }

    public String getRoleName() {
        return roleName;
    }

    public String getNote() {
        return note;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public void setNote(String note) {
        this.note = note;
    }
}

	<bean id="role_3" class="Chapter10.pojo.Role">
		<constructor-arg index="0" value="1"/>
		<constructor-arg index="1" value="总经理"/>
		<constructor-arg index="2" value="公司管理者"/>
	</bean>

2.setter注入

    <bean id="role_1" class="Chapter10.pojo.Role">
//id为对象别名 class为定义的实体类位置
        <property name="id" value="1"/>
        <property name="note" value="note_1"/>
        <property name="roleName" value="role_name_1"/>
    </bean>

3.接口注入