这篇文章主要讲解了“Spring bean有哪几种注入方式”,文中的讲解内容简单清晰,易于学习与理解,下面请大家跟着小编的思路慢慢深入,一起来研究和学习“Spring bean有哪几种注入方式”吧!
一、Set方式注入
pojo层:
1.xml 文件
test测试
二、构造函数方式注入
pojo层
2.xml文件
test测试
三、注解注入
pojo层
3.xml文件
test测试
四、JavaConfig 方式注入
pojo层
JavaConfig 类
xml文件 扫描包
测试:
五、Service层注入详解
service
serviceImpl
xml配置文件
总结
/** * @Author: crush * @Date: 2021-06-17 16:57 * version 1.0 * xml 配置注入版本 set 方式 */ public class Student1 { public String name; public String school; public void setName(String name) { this.name = name; } public void setSchool(String school) { this.school = school; } @Override public String toString() { return "Student1{" + "name='" + name + '\'' + ", school='" + school + '\'' + '}'; } }
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!--set方式注入 id是注入bean中的名字 class 是全限定类名 property 是按照set方式注入 --> <bean id="student1" class="com.crush.pojo.Student1"> <property name="name" value="wyh2"/> <property name="school" value="hngy1"/> </bean> </beans>
@Test public void student1(){ ApplicationContext context = new ClassPathXmlApplicationContext("student1.xml"); Student1 student1 = context.getBean("student1", Student1.class); System.out.println(student1); }
/** * @Author: crush * @Date: 2021-06-17 17:02 * version 1.0 * xml 配置 构造函数方式注入 */ public class Student2 { private String name; private String school; public Student2(String name, String school) { this.name = name; this.school = school; } @Override public String toString() { return "Student2{" + "name='" + name + '\'' + ", school='" + school + '\'' + '}'; } }
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!--set方式注入 id是注入bean中的名字 class 是全限定类名 constructor 是按照构造方式注入 index 是按照成员变量在构造函数中的参数的第几个 name 表示成员变量名 type 表示类型 value 表示值 ref 表示引用 可引用另外一个注入到Spring的中的值 --> <bean id="student2" class="com.crush.pojo.Student2"> <constructor-arg index="0" name="name" type="java.lang.String" value="wyh3"/> <constructor-arg name="school" value="hngy2"/> </bean> </beans>
@Test public void student2(){ ApplicationContext context = new ClassPathXmlApplicationContext("student2.xml"); Student2 student2 = context.getBean("student2", Student2.class); System.out.println(student2); }
/** * @Author: crush * @Date: 2021-06-17 17:08 * version 1.0 */ @Component public class Student3 { @Value("wyh4") private String name; @Value("hngy3") private String school; @Override public String toString() { return "Student3{" + "name='" + name + '\'' + ", school='" + school + '\'' + '}'; } }
<?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 http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <!--注解方式注入 需要扫描注解在的包 注解才会生效 --> <context:component-scan base-package="com.crush.pojo"/> </beans>
@Test public void student3(){ ApplicationContext context = new ClassPathXmlApplicationContext("student3.xml"); Student3 student3 = context.getBean("student3", Student3.class); System.out.println(student3); }
/** * @Author: crush * @Date: 2021-06-17 17:16 * version 1.0 * JavaConfig 配置 */ public class Student4 { @Value("wyh5") private String name; @Value("hngy4") private String school; @Override public String toString() { return "Student4{" + "name='" + name + '\'' + ", school='" + school + '\'' + '}'; } }
@Configuration public class Student4Config { @Bean public Student4 student4(){ return new Student4(); } }
<?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 http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.crush.config"/> </beans>
@Test public void student4(){ ApplicationContext context = new ClassPathXmlApplicationContext("student4.xml"); Student4 student4 = context.getBean("student4", Student4.class); System.out.println(student4); }
/** * @Author: crush * @Date: 2021-06-17 17:27 * version 1.0 * xml 配置 */ public interface StudentService1 { void test(); }
/** * @Author: crush * @Date: 2021-06-17 17:29 * version 1.0 * xml 配置 */ public class StudentService1Impl implements StudentService1{ @Override public void test() { System.out.println("===StudentDao1Impl==="); } }
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean id="studentService1" class="com.crush.dao.StudentService1" /> </beans>
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