湘潭网小编为大家带来以下内容:
这篇“Spring框架之IOC的特点是什么”文章的知识点大部分人都不太理解,所以小编给大家总结了以下内容,内容详细,步骤清晰,具有一定的借鉴价值,希望大家阅读完这篇文章能有所收获,下面我们一起来看看这篇“Spring框架之IOC的特点是什么”文章吧。一、对spring的理解spring是一个开源框架,它由Rod Johnson 创建。它是为了解决企业应用开发的复杂性而创建的。
目的:解决企业应用开发的复杂性
功能:使用基本的JavaBean代替EJB,并提供了更多的企业应用功能
范围:任何Java应用
简单来说,Spring是一个轻量级的控制反转(IoC)和面向切面(AOP)的容器框架。
二、spring中ioc的特点建一个maven项目
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.yzp</groupId> <artifactId>T280_spring</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>T280_spring Maven Webapp</name> <url>http://maven.apache.org</url> <!-- 将当前项目所用的jar包依赖版本定义在外部目的在于所有jar 包版本进行统一管理--> <properties><spring.version>5.0.1.RELEASE</spring.version><javax.servlet.version>4.0.0</javax.servlet.version><junit.version>4.12</junit.version> </properties> <dependencies> <dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency><!-- 2、导入spring依赖 --><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>${spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId><version>${spring.version}</version></dependency><!-- 5.1、junit --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version><scope>test</scope></dependency><!-- 5.2、servlet --><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>${javax.servlet.version}</version><scope>provided</scope></dependency> </dependencies> <build> <finalName>T280_spring</finalName> <plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.7.0</version><configuration><source>1.8</source><target>1.8</target><encoding>UTF-8</encoding></configuration></plugin></plugins> </build></project>web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <display-name>Archetype Created Web Application</display-name></web-app>2.1控制反转建一个com.yzp.biz的包
UserBiz
package com.yzp.biz;public interface UserBiz {void list();}建一个com.yzp.biz.impl的包
UserBizImpl1
package com.yzp.biz.impl;import com.yzp.biz.UserBiz;public class UserBizImpl1 implements UserBiz{@Overridepublic void list() {System.out.println("查询用户数据。。按照年龄排序。");}}UserBizImpl2
package com.yzp.biz.impl;import com.yzp.biz.UserBiz;public class UserBizImpl2 implements UserBiz{@Overridepublic void list() {System.out.println("查询用户数据。。按照入职时间排序。");}}建一个com.yzp.web的包
OrderAction
package com.yzp.web;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class OrderAction {private UserBiz userBiz = new UserBizImpl1();public void list() {userBiz.list();}}UserAction
package com.yzp.web;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class UserAction {private UserBiz userBiz = new UserBizImpl1();public void list() {userBiz.list();}}常规做法即运用spring之前的处理方法
需求:同时在用户模块,订单模块拿到所有的用户数据需求变更1:同时在用户模块,订单模块拿到所有的用户数据,并且要求用户数据是通过年龄排序的对应策略:修改UserBiz中list方法,添加排序功能需求变更2:同时在用户模块,订单模块拿到所有的用户数据,并且要求用户数据是通过注册时间排序的对应策略,修改UserBiz中list方法,添加排序功能,按照时间点排序
总结:最原始:频繁修改业务层biz的代码多实现:凡是涉及到用户业务层调用的地方,都需要修改代码
将spring的配置文件加入
spring-context.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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"></beans>注意:一定要在有网络的情况下进行,否则约束不生效
IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理
spring-context.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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><!-- <bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz1"></bean> --><bean class="com.yzp.biz.impl.UserBizImpl2" id="userBiz2"></bean><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz2"></property></bean><bean class="com.yzp.web.OrderAction" id="orderAction"></bean></beans>UserAction
package com.yzp.web;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class UserAction {//private UserBiz userBiz = new UserBizImpl1();private UserBiz userBiz;public void list() {userBiz.list();}public UserBiz getUserBiz() {return userBiz;}public void setUserBiz(UserBiz userBiz) {this.userBiz = userBiz;}}建一个com.yzp.ioc的包
在里面建一个Demo1的类
建模,打印com.yzp.biz.impl.UserBizImpl2中的语句
package com.yzp.ioc;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.yzp.web.UserAction;public class Demo1 {@SuppressWarnings("resource")public static void main(String[] args) {//建模ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/spring-context.xml");UserAction userAction = (UserAction) context.getBean("userAction");userAction.list();}}运行结果:
可见 能拿到
总结
1.对spring框架的配置文件进行建模,建模之后spring-context.xml中所有的Javabean信息 都会加载进spring容器的上下文中2.上下文中就包含了spring-context.xml 所有对象
测试orderaction也拿到相同结果,配置和orderaction都如useraction一致修改
package com.yzp.web;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class OrderAction {//private UserBiz userBiz = new UserBizImpl1();private UserBiz userBiz;public void list() {userBiz.list();}public UserBiz getUserBiz() {return userBiz;}public void setUserBiz(UserBiz userBiz) {this.userBiz = userBiz;}}<?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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><!-- <bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz1"></bean> --><bean class="com.yzp.biz.impl.UserBizImpl2" id="userBiz2"></bean><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz2"></property></bean><bean class="com.yzp.web.OrderAction" id="orderAction"><property name="userBiz" ref="userBiz2"></property></bean></beans>package com.yzp.ioc;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.yzp.web.OrderAction;import com.yzp.web.UserAction;public class Demo1 {@SuppressWarnings("resource")public static void main(String[] args) {//建模ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/spring-context.xml");UserAction userAction = (UserAction) context.getBean("userAction");userAction.list();OrderAction orderAction = (OrderAction) context.getBean("orderAction");orderAction.list();}}结果:
若是要按年龄排序,就只需要修改配置文件就OK了
<?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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz2"></bean><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz2"></property></bean><bean class="com.yzp.web.OrderAction" id="orderAction"><property name="userBiz" ref="userBiz2"></property></bean></beans>2.2注入依赖方式① set注入UserAction
package com.yzp.web;import java.util.List;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class UserAction {//private UserBiz userBiz = new UserBizImpl1();private UserBiz userBiz;public UserBiz getUserBiz() {return userBiz;}public void setUserBiz(UserBiz userBiz) {this.userBiz = userBiz;}private String name;private int age;private List<String> hobby;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public List<String> getHobby() {return hobby;}public void setHobby(List<String> hobby) {this.hobby = hobby;}public void list() {System.out.println(name);System.out.println(age);System.out.println(hobby);userBiz.list();}}<?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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz2"></bean><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz2"></property><!--set注入 --><property name="age" value="22"></property><property name="name" value="cdl"></property><property name="hobby"><list><value>篮球</value><value>足球</value><value>唱歌</value></list></property></bean><bean class="com.yzp.web.OrderAction" id="orderAction"><property name="userBiz" ref="userBiz2"></property></bean></beans>package com.yzp.ioc;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.yzp.web.OrderAction;import com.yzp.web.UserAction;public class Demo1 {@SuppressWarnings("resource")public static void main(String[] args) {//建模ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/spring-context.xml");UserAction userAction = (UserAction) context.getBean("userAction");userAction.list();OrderAction orderAction = (OrderAction) context.getBean("orderAction");orderAction.list();}}结果;
方式② 构造注入OrderAction
package com.yzp.web;import java.util.List;import com.yzp.biz.UserBiz;import com.yzp.biz.impl.UserBizImpl1;public class OrderAction {//private UserBiz userBiz = new UserBizImpl1();private UserBiz userBiz;public UserBiz getUserBiz() {return userBiz;}public void setUserBiz(UserBiz userBiz) {this.userBiz = userBiz;}private String name;private int age;private List<String> hobby;public OrderAction(String name, int age, List<String> hobby) {super();this.name = name;this.age = age;this.hobby = hobby;}public OrderAction() {super();// TODO Auto-generated constructor stub}public void list() {System.out.println(name);System.out.println(age);System.out.println(hobby);userBiz.list();}}<?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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz2"></bean><!--set注入 --><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz2"></property><property name="age" value="22"></property><property name="name" value="cdl"></property><property name="hobby"><list><value>篮球</value><value>足球</value><value>唱歌</value></list></property></bean><!-- 构造注入 --><bean class="com.yzp.web.OrderAction" id="orderAction"><property name="userBiz" ref="userBiz2"></property><constructor-arg name="name" value="yzp"></constructor-arg><constructor-arg name="age" value="23"></constructor-arg><constructor-arg name="hobby"><list><value>篮球1</value><value>足球1</value><value>唱歌1</value></list></constructor-arg></bean></beans>运行结果:
方式③ 自动装配将set和构造的注入 注释
byType不报错 byName报错
自动装配 default-autowire="byName" byName:是通过spring管理的bean对象的ID进行查找,如果找不到,则注入失败,反之成功 byType:是通过spring管理的bean对象的接口实现类进行查找,如果没有或者2个以上,则注入失败,反之成功
三、spring与web容器的整合分析:
spring与web容器的整合原理 why:建模的过程是十分耗时的 解决问题: 1.建模必不可少 2.建模只保障只执行一次 3.建模后期望在每一个servlet都能够拿到spring的上下文对象ClassPathXmlApplicationContext how: 1.监听器的初始化方法 只执行一次 2.spring的上下文要存放在Tomcat上下文中
建一个包com.yzp.ioc.listener
package com.yzp.ioc.listener;import javax.servlet.ServletContext;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;import org.springframework.context.support.ClassPathXmlApplicationContext;public class SpringLoadListener implements ServletContextListener{@Overridepublic void contextInitialized(ServletContextEvent sce) {System.out.println("初始化执行");ServletContext servletContext = sce.getServletContext();String springConfigLocation = servletContext.getInitParameter("springConfigLocation");System.out.println(springConfigLocation+"...");//拿到spring上下文ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/spring-context.xml");//将spring的上下文保存在Tomcat上下文中servletContext.setAttribute("springContext", context);}}在com.yzp.ioc中建一个类DemoServlet
package com.yzp.ioc;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.yzp.web.UserAction;@WebServlet("/springDemo")public class DemoServlet extends HttpServlet{@Overrideprotected void service(HttpServletRequest arg0, HttpServletResponse arg1){//ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("/spring-context.xml");ClassPathXmlApplicationContext context = (ClassPathXmlApplicationContext) arg0.getServletContext().getAttribute("springContext");UserAction userAction = (UserAction) context.getBean("userAction");userAction.list();}}spring-context.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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"><!-- IOC的主要作用管理整个项目的Javabean:依靠依赖注入、控制反转的特点进行管理 --><bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz"></bean><bean class="com.yzp.biz.impl.UserBizImpl1" id="userBiz1"></bean><!--set注入 --><bean class="com.yzp.web.UserAction" id="userAction"><property name="userBiz" ref="userBiz1"></property> <property name="age" value="22"></property><property name="name" value="cdl"></property><property name="hobby"><list><value>篮球</value><value>足球</value><value>唱歌</value></list></property></bean><!-- 构造注入 --><bean class="com.yzp.web.OrderAction" id="orderAction"><property name="userBiz" ref="userBiz1"></property> <constructor-arg name="name" value="yzp"></constructor-arg><constructor-arg name="age" value="23"></constructor-arg><constructor-arg name="hobby"><list><value>篮球1</value><value>足球1</value><value>唱歌1</value></list></constructor-arg></bean><!-- 自动装配 --></beans>web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <display-name>Archetype Created Web Application</display-name><context-param><param-name>springConfigLocation</param-name><param-value>/applicationContext.xml</param-value></context-param><listener><listener-class>com.yzp.ioc.listener.SpringLoadListener</listener-class></listener></web-app>以上就是关于“Spring框架之IOC的特点是什么”这篇文章的内容,相信大家都有了一定的了解,希望小编分享的内容对大家有帮助,若想了解更多相关的知识内容,请关注花开半夏行业资讯频道。
君子莲(www.junzilian.com)湖南省长沙、株洲、湘潭城市宣传信息网,提供房产,人才招聘,家居装饰,教育,论坛,旅游,特产,美食,天气,娱乐,企业等资讯。