Spring IOC的应用

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-contextartifactId>
    <version>5.3.19version>
dependency>
 
<dependency>
    <groupId>junitgroupId>
    <artifactId>junitartifactId>
    <version>4.13.2version>
    <scope>testscope>
dependency>

"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 id="userService" class="com.lagou.service.impl.TransferServiceImpl">
bean>

<bean id="userService" class="com.lagou.factory.BeanFactory" 
    factory-method="getTransferService">bean>

<bean id="beanFactory"
    class="com.lagou.factory.instancemethod.BeanFactory">bean>
<bean id="transferService" factory-bean="beanFactory" 
    factory-method="getTransferService">bean>

<bean id="transferService"
    class="com.lagou.service.impl.TransferServiceImpl" scope="singleton">
bean>

<bean id="userDao" class="com.test.UserDao">
    <constructor-arg name="name" value="zhangsan"/>
    <constructor-arg name="age" value="18"/>
    <constructor-arg name="friend" ref="user"/>
bean>

<bean id="userDao" class="com.test.UserDao">
    <property name="name" value="zhangsan"/>
    <property name="age" value="18"/>
    <property name="friend" ref="user"/>
bean>

<bean id="userDao" class="com.test.UserDao">
    <property name="myArray">
        <array>
            <value>array1value>
            <value>array2value>
            <value>array3value>
        array>
    property>
    <property name="myMap">
        <map>
            <entry key="key1" value="value1"/>
            <entry key="key2" value="value2"/>
        map>
    property>
    <property name="mySet">
        <set>
            <value>set1value>
            <value>set2value>
        set>
    property>
    <property name="myProperties">
        <props>
            <prop key="prop1">value1prop>
            <prop key="prop2">value2prop>
        props>
    property>
bean>

@Autowired
private AccountDao accountDao;

@Autowired
@Qualifier(name="jdbcAccountDaoImpl")
private AccountDao accountDao;

@Resource
private AccountDao accountDao;
@Resource(name="studentDao")
private StudentDao studentDao;
@Resource(type="TeacherDao")
private TeacherDao teacherDao;
@Resource(name="manDao",type="ManDao")
private ManDao manDao;

<dependency>
    <groupId>javax.annotationgroupId>
    <artifactId>javax.annotation-apiartifactId>
    <version>1.3.2version>
dependency>

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
UserDao userDao = (UserDao)context.getBean("userDao");

web-app PUBLIC
    "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
    <display-name>Archetype Created Web Applicationdisplay-name>
    
    <context-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:applicationContext.xmlparam-value>
    context-param>
    
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
    listener>
web-app>

web-app PUBLIC
    "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
    <display-name>Archetype Created Web Applicationdisplay-name>
    
    <context-param>
        <param-name>contextClassparam-name>
        <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContextparam-value>
    context-param>
    
    <context-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>com.lagou.edu.SpringConfigparam-value>
    context-param>
    
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
    listener>
web-app>

<bean id="testBean" calss="com.test.LazyBean" lazy-init="true" />

<beans default-lazy-init="true">
    
beans>

public class UserFactoryBean implements FactoryBean {
    private String userInfo;//名字,年龄
 
    public void setUserInfo(String userInfo) {
        this.userInfo = userInfo;
    }
 
    //自定义bean的创建过程
    @Override
    public User getObject() throws Exception {
        User user = new User();
        String[] strings = userInfo.split(",");
        user.setName(strings[0]);
        user.setAge(Integer.parseInt(strings[1]));
        return user;
    }
 
    //返回bean类型
    @Override
    public Class getObjectType() {
        return User.class;
    }
    //返回作用域是否单例，默认单例
    @Override
    public boolean isSingleton() {
        return FactoryBean.super.isSingleton();
    }
}

<bean id="userFactoryBean" class="com.test.UserFactoryBean">
    <property name="userInfo" value="张三,19"/>
bean>

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
User userDao = (User)context.getBean("userFactoryBean");
System.out.println(userDao);