Spring

2022-07-18 10:00:57 阅读：98 来源： 互联网

标签：Student Spring class println student test public

Spring

xml开发

导入依赖

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.3.13</version>
</dependency>

Spring配置文件

在resources包下

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

</beans>

配置上下文点一下提示就好

Main方法

public class Main {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MainConfiguration.class);
        

    }
}

注册javabean，创建一个Student类

@Data  // 导入lombok依赖才能用
public class Student {
    int age;
    String name;
    
}

配置文件添加 bean

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
<bean name="Student" class="com.test.bean.Student"/>
// -> <bean id="Student" class="com.test.bean.Student"/>
</beans>

Main方法

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

bean 默认单例模式

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        Student student2 = (Student) context.getBean("student");
        System.out.println(student);
        System.out.println(student2);
        System.out.println(student == student2);
    }
}

运行：

com.test.bean.Student@1ed4004b
com.test.bean.Student@1ed4004b
true

修改作用域

默认单例，修改为原型

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">


<bean name="student" class="com.test.bean.Student" scope="prototype"/>

</beans>

运行：

com.test.bean.Student@72d818d1
com.test.bean.Student@6e06451e
false

原型模式每次创建一个新对象

定义初始化和销毁方法

bean 学生类

public class Student {
    int age;
    String name;

    public Student() {
        System.out.println("我是构造器");
    }

    public void init(){
        System.out.println("我是初始化方法");
    }
    public void destroy(){
        System.out.println("我是销毁方法");
    }
}

配置xml文件

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean name="student" class="com.test.bean.Student" init-method="init" destroy-method="destroy"/>

</beans>

main方法

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);
        context.close();
    }
}

依赖注入

注入属性

需要有set方法，把实体类加上@Data，一了百了

配置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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean name="student" class="com.test.bean.Student">
        <property name="name" value="小明"/>
        <property name="age" value="22"/>
    </bean>

</beans>

main方法

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

注入对象类型

定义一个Card卡片类

public class Card { }

学生类

@Data
public class Student {
    int age;
    String name;
    Card card;

}

test.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean class="com.test.bean.Card" name="card"/>
    <bean name="student" class="com.test.bean.Student">
        <property name="name" value="小明"/>
        <property name="age" value="22"/>
        <property name="card" ref="card"/>
    </bean>

</beans>

注入集合

List

Student.java

@Data
public class Student {
    int age;
    String name;
    List<String> list;

}

main方法

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

test.xml

<bean name="student" class="com.test.bean.Student">
    <property name="list">
        <list>
            <value>小明</value>
            <value>小红</value>
            <value>小刚</value>
        </list>
        // list 可以换成 map
    </property>
</bean>

map

Student.java

@Data
public class Student {
    int age;
    String name;
    Map<String , Integer> map;
     
}

main方法

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

test.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean name="student" class="com.test.bean.Student">
        <property name="map">
            <map>
                <entry key="小明" value="100"/>
                <entry key="小红" value="200"/>
                <entry key="小亮" value="103"/>
            </map>
        </property>
    </bean>

</beans>

自动装配

test.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean name="card" class="com.test.bean.Card"/>
    <bean name="student" class="com.test.bean.Student" autowire="byType"/>


</beans>

card.java

@Data
public class Card { }

student.java

@Data
public class Student {
    int age;
    String name;
    Card card;

}

main.java

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

构造器注入

test.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">


    <bean name="card" class="com.test.bean.Card"/>
    <bean name="student" class="com.test.bean.Student" autowire="byType">
        <constructor-arg value="12" name="age"/>
<!--        <constructor-arg value="12" index="0"/>-->
    </bean>


</beans>

student.java

package com.test.bean;

import lombok.Data;

@Data
public class Student {
    int age;
    String name;
    Card card;

    public Student(int age) {
        this.age = age;
    }
}

main.java

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);

    }
}

面向切面编程

导入依赖

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>5.3.13</version>
</dependency>

注意点

需要切入的类，类的哪个方法需要被切入
切入之后需要执行什么动作
是在方法执行前切入还是在方法执行后切入
如何告诉Spring需要进行切入

可能有坑：

通配符的匹配很全面, 但无法找到元素 'aop:config' 的声明_灯下驼贼的博客-CSDN博客

test.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:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop.xsd "
>


    <bean name="student" class="com.test.bean.Student"/>
    <bean name="aopTest" class="com.test.aop.AopTest"/>

    <aop:config>
        <aop:pointcut id="test" expression="execution(* com.test.bean.Student.test(..))"/>
        <aop:aspect ref="aopTest">
            <aop:before method="before" pointcut-ref="test"/>
            <aop:after-returning method="after" pointcut-ref="test"/>
        </aop:aspect>
    </aop:config>

</beans>

student.java

@Data
public class Student {
    int age;
    String name;
    Card card;

    public String test(String name){
        System.out.println("hello,world");
        return name;
    }

}

main.java

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student =  context.getBean(Student.class);
        student.test("h");

    }
}

aoptest.java

public class AopTest {
    //执行之后的方法
    public void after(){
        System.out.println("我是执行之后");
    }

    //执行之前的方法
    public void before(){
        System.out.println("我是执行之前");
    }
}

--->

public void after(JoinPoint point){
    System.out.println(point.getTarget());
    System.out.println(Arrays.toString(point.getArgs()));
    System.out.println("我是执行之后");
}

环绕方法

test.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:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop.xsd "
>


    <bean name="student" class="com.test.bean.Student"/>
    <bean name="aopTest" class="com.test.aop.AopTest"/>

    <aop:config>
        <aop:pointcut id="test" expression="execution(* com.test.bean.Student.test(..))"/>
        <aop:aspect ref="aopTest">
            <aop:around method="around" pointcut-ref="test"/>
        </aop:aspect>
    </aop:config>

</beans>

aoptest.java

public class AopTest {

    public Object around(ProceedingJoinPoint joinPoint)throws Throwable{
        System.out.println("方法开始之前");
        Object value = joinPoint.proceed();
        System.out.println("方法完成" + value);
        return value;
    }

}

student.java

@Data
public class Student {
    int age;
    String name;
    Card card;

    public String test(String name){
        System.out.println("hello,world");
        return name;
    }

}

main.java

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("test.xml");
        Student student =  context.getBean(Student.class);
        student.test("h");


    }
}

接口实现

aoptest.java

public class AopTest implements MethodBeforeAdvice, AfterReturningAdvice {

    @Override
    public void before(Method method, Object[] args, Object target) throws Throwable {
        System.out.println("我是方法之前");
    }

    @Override
    public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
        System.out.println("我是方法之后");
    }
}

test.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:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop.xsd "
>


    <bean name="student" class="com.test.bean.Student"/>
    <bean name="aopTest" class="com.test.aop.AopTest"/>

    <aop:config>
        <aop:pointcut id="stu" expression="execution(* com.test.bean.Student.test(String))"/>
        <aop:advisor advice-ref="aopTest" pointcut-ref="stu"/>
    </aop:config>

</beans>

注解开发

在配置文件中创建bean

mainconfiguration.java

@Configuration
public class MainConfiguration {
    @Bean
    @Scope("prototype")
    public Card card(){
        return new Card();
    }
}

main.java

public class Main {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MainConfiguration.class);
        Card card = context.getBean(Card.class);
        System.out.println(card);
    }
}

自动扫描包

mainconfiguration.java

@Configuration
@ComponentScan("com.test.bean")
public class MainConfiguration {

}

student.java

@Data
@Component
public class Student {
    int age;
    String name;
    Card card;

    public String test(String name){
        System.out.println("hello,world");
        return name;
    }

}

main.java

public class Main {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MainConfiguration.class);
        Student student = context.getBean(Student.class);
        System.out.println(student);
    }
}

添加对象类型

@Data
@Component
public class Student {
    int age;
    String name;
    @Resource
    Card card;

    public String test(String name){
        System.out.println("hello,world");
        return name;
    }

}

注解实现AOP

MainConfiguration.java

@EnableAspectJAutoProxy
@Configuration
@ComponentScan("com.test.bean")
public class MainConfiguration {

}

aoptest.java

@Component
@Aspect
public class AopTest  {

    @Before("execution(* com.test.bean.Student.test(..))")
    public void before(JoinPoint joinPoint) {
        System.out.println(Arrays.toString(joinPoint.getArgs()));
        System.out.println("我是方法之前");
    }

    @AfterReturning(value = "execution(* com.test.bean.Student.test(..))", returning = "returnVal")
    public void after(Object returnVal){
        System.out.println("方法已返回，结果为："+returnVal);
    }

    @Around("execution(* com.test.bean.Student.test(..))")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        System.out.println("方法执行之前！");
        Object val = point.proceed();
        System.out.println("方法执行之后！");
        return val;
    }




}

另外@Import 可以引入其他类的配置

标签：Student,Spring,class,println,student,test,public
来源： https://www.cnblogs.com/instore/p/16489361.html

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ICode9

Spring

Spring

xml开发

导入依赖

Spring配置文件

Main方法

注册javabean，创建一个Student类

配置文件添加 bean

Main方法

bean 默认单例模式

定义初始化和销毁方法

依赖注入

注入属性

注入对象类型

注入集合

List

map

自动装配

构造器注入

面向切面编程

导入依赖

注意点

环绕方法

接口实现

注解开发

在配置文件中创建bean

自动扫描包

添加对象类型

注解实现AOP