【spring】ApplicationContext的实现-编程知识

- - - 一、ClassPathXmlApplicationContext
    - - 1.1 说明
      - 1.2 代码示例
      - 1.3 截图示例
    - 二、FileSystemXmlApplicationContext
    - - 2.1 说明
      - 2.2 代码示例
      - 2.3 加载xml的bean定义示例
    - 三、AnnotationConfigApplicationContext
    - - 3.1 说明
      - 3.2 代码示例
      - 3.3 截图示例
    - 四、AnnotationConfigServletWebServerApplicationContext
    - - 4.1 说明
      - 4.2 代码示例
      - 4.2 截图示例

一、ClassPathXmlApplicationContext

1.1 说明

1. 较为经典的容器，基于classpath下xml格式的配置文件来创建
2. 在类路径下读取xml文件
3. 现在已经很少用了，做个了解

1.2 代码示例

1. 学生类

package com.learning.application_context;public class Student {private Card card;public void setCard(Card card){this.card = card;}public Card getCard(){return this.card;}
}

2. 卡类

package com.learning.application_context;public class Card {
}

3. xml配置

<?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="card" class="com.learning.application_context.Card"/><bean id="student" class="com.learning.application_context.Student"><property name="card" ref="card"></property></bean>
</beans>

4. 测试类

package com.learning.application_context;import org.springframework.context.support.ClassPathXmlApplicationContext;public class ApplicationContextTest {public static void main(String[] args) {testClassPathXmlApplicationContext();}private static void testClassPathXmlApplicationContext(){ClassPathXmlApplicationContext classPathXmlApplicationContext = new ClassPathXmlApplicationContext("class-path-xml-application-context.xml");for (String beanDefinitionName : classPathXmlApplicationContext.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}System.out.println(classPathXmlApplicationContext.getBean(Student.class).getCard());}
}

1.3 截图示例

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二、FileSystemXmlApplicationContext

2.1 说明

1. 基于读取文件系统的xml来创建

2.2 代码示例

package com.learning.application_context;import org.springframework.context.support.FileSystemXmlApplicationContext;public class ApplicationContextTest {public static void main(String[] args) {testFileSystemXmlApplicationContext();}private static void testFileSystemXmlApplicationContext(){// 具体配置的路径按实际情况来写FileSystemXmlApplicationContext fileSystemXmlApplicationContext = new FileSystemXmlApplicationContext("D:\\IdeaProject\\spring-framework\\spring-learning\\src\\main\\resources\\class-path-xml-application-context.xml");for (String beanDefinitionName : fileSystemXmlApplicationContext.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}System.out.println(fileSystemXmlApplicationContext.getBean(Student.class).getCard());}
}

private static void testFileSystemXmlApplicationContext(){// 绝对目录
//		FileSystemXmlApplicationContext fileSystemXmlApplicationContext = new FileSystemXmlApplicationContext("D:\\IdeaProject\\spring-framework\\spring-learning\\src\\main\\resources\\class-path-xml-application-context.xml");// 相对目录,但要设置工作目录FileSystemXmlApplicationContext fileSystemXmlApplicationContext = new FileSystemXmlApplicationContext("src\\main\\resources\\class-path-xml-application-context.xml");for (String beanDefinitionName : fileSystemXmlApplicationContext.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}System.out.println(fileSystemXmlApplicationContext.getBean(Student.class).getCard());}

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2.3 加载xml的bean定义示例

package com.learning.application_context;import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.core.io.ClassPathResource;public class ApplicationContextTest {public static void main(String[] args) {loadXmlBeanDefinitionTest();}private static void loadXmlBeanDefinitionTest(){DefaultListableBeanFactory defaultListableBeanFactory = new DefaultListableBeanFactory();System.out.println("读取前的BeanDefinitionName====");for (String beanDefinitionName : defaultListableBeanFactory.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}XmlBeanDefinitionReader xmlBeanDefinitionReader = new XmlBeanDefinitionReader(defaultListableBeanFactory);xmlBeanDefinitionReader.loadBeanDefinitions(new ClassPathResource("class-path-xml-application-context.xml"));System.out.println("读取后的BeanDefinitionName====");for (String beanDefinitionName : defaultListableBeanFactory.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}}
}

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三、AnnotationConfigApplicationContext

3.1 说明

1. 较为经典的容器，基于java配置类来创建
2. 会默认添加几个后处理器org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
3. 用xml的方式是用<context:annotation-config/>来添加的

3.2 代码示例

package com.learning.application_context;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class Config {@Beanpublic Student student(Card card){Student student = new Student();student.setCard(card);return student;}@Beanpublic Card card(){return new Card();}
}

package com.learning.application_context;import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class ApplicationContextTest {public static void main(String[] args) {testAnnotationConfigApplicationContext();}private static void testAnnotationConfigApplicationContext(){AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext(Config.class);for (String beanDefinitionName : annotationConfigApplicationContext.getBeanDefinitionNames()) {System.out.println(beanDefinitionName);}}
}

3.3 截图示例

在这里插入图片描述

四、AnnotationConfigServletWebServerApplicationContext

4.1 说明

1. 可以加载tomcat服务来工作
2. 需要加载springboot相关的jar包

4.2 代码示例

package com.learning.application_context;import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletRegistrationBean;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.servlet.server.ServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@Configuration
public class WebConfig {// 定义一个tomcat服务工厂@Beanpublic ServletWebServerFactory servletWebServerFactory(){return new TomcatServletWebServerFactory();}@Beanpublic DispatcherServlet dispatcherServlet(){return new DispatcherServlet();}@Beanpublic DispatcherServletRegistrationBean registrationBean(DispatcherServlet dispatcherServlet){return new DispatcherServletRegistrationBean(dispatcherServlet, "/");}@Bean("/hello")public Controller controllerOne(){return new Controller() {@Overridepublic ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {httpServletResponse.getWriter().print("hello");return null;}};}
}

package com.learning.application_context;import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletRegistrationBean;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.servlet.server.ServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@Configuration
public class WebConfig {// 定义一个tomcat服务工厂@Beanpublic ServletWebServerFactory servletWebServerFactory(){return new TomcatServletWebServerFactory();}@Beanpublic DispatcherServlet dispatcherServlet(){return new DispatcherServlet();}@Beanpublic DispatcherServletRegistrationBean registrationBean(DispatcherServlet dispatcherServlet){return new DispatcherServletRegistrationBean(dispatcherServlet, "/");}@Bean("/hello")public Controller controllerOne(){return new Controller() {@Overridepublic ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {httpServletResponse.getWriter().print("hello");return null;}};}
}