【spring】ApplicationContext的实现
目录
-
-
-
- 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
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-
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
- 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
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());
}
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);
}
}
}
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
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 {
@Bean
public Student student(Card card){
Student student = new Student();
student.setCard(card);
return student;
}
@Bean
public 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
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
@Bean
public ServletWebServerFactory servletWebServerFactory(){
return new TomcatServletWebServerFactory();
}
@Bean
public DispatcherServlet dispatcherServlet(){
return new DispatcherServlet();
}
@Bean
public DispatcherServletRegistrationBean registrationBean(DispatcherServlet dispatcherServlet){
return new DispatcherServletRegistrationBean(dispatcherServlet, "/");
}
@Bean("/hello")
public Controller controllerOne(){
return new Controller() {
@Override
public 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
@Bean
public ServletWebServerFactory servletWebServerFactory(){
return new TomcatServletWebServerFactory();
}
@Bean
public DispatcherServlet dispatcherServlet(){
return new DispatcherServlet();
}
@Bean
public DispatcherServletRegistrationBean registrationBean(DispatcherServlet dispatcherServlet){
return new DispatcherServletRegistrationBean(dispatcherServlet, "/");
}
@Bean("/hello")
public Controller controllerOne(){
return new Controller() {
@Override
public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
httpServletResponse.getWriter().print("hello");
return null;
}
};
}
}
4.2 截图示例
