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Preface:

Title party ha ha ha, this is a blogger learned in school to study the injection ways, write it down, it is a convenient late his review, two is also want to share, although this several injection method is very common, very basic, no technical content, this blog is about bloggers the privacy of their blogs.

Dillygerba traffic, hahaha.

1. Set injection

The set method and constructor method are very basic and suitable for beginners

Pojo layer:

/ * * *@Author: crush
 * @Date: 2021-06-17 16:57 * Version 1.0 * XML Configuration injection version Set mode */
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(a) {
        return "Student1{" +
                "name='" + name + '\' ' +
                ", school='" + school + '\' ' +
                '} '; }}Copy the code

1. The XML file

Id is the name in the injected bean. Class is the fully qualified class name. Property is injected as setCopy the code

      
<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">

    <! Class is the fully qualified class name. Property is injected as set.
    <bean id="student1" class="com.crush.pojo.Student1">
        <property name="name" value="wyh1"/>
        <property name="school" value="hngy1"/>
    </bean>
</beans>
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The test test

    @Test
    public void student1(a){
        ApplicationContext context = new ClassPathXmlApplicationContext("student1.xml");
        Student1 student1 = context.getBean("student1", Student1.class);
        System.out.println(student1);
    }
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Constructor injection

Pojo layer

/ * * *@Author: crush
 * @Date: 2021-06-17 17:02 * Version 1.0 * XML configuration constructor injection */
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(a) {
        return "Student2{" +
                "name='" + name + '\' ' +
                ", school='" + school + '\' ' +
                '} '; }}Copy the code

2. The XML file

Id is the name of the injected bean. Class is the fully qualified class name. Constructor is the constructor for injecting index. Name is the name of the member variable You can reference another value injected into SpringCopy the code

      
<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">

    <! Constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor constructor Ref means that a reference can refer to another value injected into Spring -->
    <bean id="student2" class="com.crush.pojo.Student2">
        <constructor-arg index="0"  name="name" type="java.lang.String" value="wyh2"/>
        <constructor-arg name="school" value="hngy2"/>
    </bean>
</beans>
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The test test

    @Test
    public void student2(a){
        ApplicationContext context = new ClassPathXmlApplicationContext("student2.xml");
        Student2 student2 = context.getBean("student2", Student2.class);
        System.out.println(student2);
    }
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Annotation injection

Pojo layer

/ * * *@Author: crush
 * @Date: 2021-06-17 17:08
 * version 1.0
 */
@Component
public class Student3 {
    @Value("wyh3")
    private String name;

    @Value("hngy3")
    private String school;

    @Override
    public String toString(a) {
        return "Student3{" +
                "name='" + name + '\' ' +
                ", school='" + school + '\' ' +
                '} '; }}Copy the code

3. The XML file

<? 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- <context:component-scan base-package="com.crush.pojo"/>
</beans>
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The test test

    @Test
    public void student3(a){
        ApplicationContext context = new ClassPathXmlApplicationContext("student3.xml");
        Student3 student3 = context.getBean("student3", Student3.class);
        System.out.println(student3);
    }
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Iv. JavaConfig injection

Pojo layer

/ * * *@Author: crush
 * @Date: 2021-06-17 17:16 * Version 1.0 * JavaConfig configuration */
public class Student4 {
    @Value("wyh4")
    private String name;
    @Value("hngy4")
    private String school;
    
    @Override
    public String toString(a) {
        return "Student4{" +
                "name='" + name + '\' ' +
                ", school='" + school + '\' ' +
                '} '; }}Copy the code

JavaConfig class

@Configuration
public class Student4Config {

    @Bean
    public Student4 student4(a){
        return newStudent4(); }}Copy the code

XML file scan package

      
<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>
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Testing:

    @Test
    public void student4(a){
        ApplicationContext context = new ClassPathXmlApplicationContext("student4.xml");
        Student4 student4 = context.getBean("student4", Student4.class);
        System.out.println(student4);
    }
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Detailed explanation of Service layer injection

service

/ * * *@Author: crush
 * @Date: 2021-06-17 17:27 * Version 1.0 * XML configuration */
public interface StudentService1 {
    void test(a);
}

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serviceImpl

/ * * *@Author: crush
 * @Date: 2021-06-17 17:29 * Version 1.0 * XML configuration */
public class StudentService1Impl implements StudentService1{
    @Override
    public void test(a) {
        System.out.println("===StudentDao1Impl==="); }}Copy the code

XML configuration file

      
<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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Note the same way as above, I will not repeat the explanation

conclusion

These ways of bloggers are more commonly used by teachers. There should be no problem for us students who are just getting started. There may be other better ways on the Internet that we need to explore together. Three companies oh!!