Spring IOC

1：项目添加spring的支持

a.普通java项目配置如下

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>3.2.9.RELEASE</version>
  </dependency>

b.web项目配置如下

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>3.2.9.RELEASE</version>
  </dependency>

 同时在web.xml中配置spring的监听器

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            <!-- 此路径为Spring配置文件applicationContext.xml路径 -->
            classpath:/applicationContext.xml
        </param-value>
    </context-param>
    
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

2：实体配置

Address.java

public class Address {
    private String address;
}

Person.java

public class Person {
    private String name;
    private Address address;
    private List<String> friends;
    private Set<String> family;
    private Map<String,String> relation;
    private Properties identity;
    public void init() {
        System.out.println("init");
    }
    
    public void destroy() {
        System.out.println("destroy");
    }
}      

 3：配置applicationContext.xml，具体配置如下

<?xml version="1.0" encoding="UTF-8"?>
<beans
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
    <bean id="address" class="test.Address">
        <!-- 向构造函数注入类对象 <constructor-arg index = "0" ref = "address"/> -->
        <constructor-arg index = "0" value = "zhejiang"/>
    </bean>

    <bean id="person" class="test.Person" init-method="init" destroy-method="destroy" scope="prototype">
        <!-- 注入普通属性 -->
        <property name="name" value="zanglitao"/>
        
        <!-- 注入类对象 -->
        <property name="address" ref="address"/>
        
        <!-- 注入List -->
        <property name="friends">
            <list>
                <!-- 向List中注入类对象 <ref bean=""/> -->
                <value>yao</value>
                <value>ye</value>
                <value>pin</value>
                <value>cao</value>
            </list>
        </property>
        
        <!-- 注入Set -->
        <property name="family">
            <set>
                <!-- 向Set中注入类对象 <ref bean=""/> -->
                <value>father</value>
                <value>mather</value>
            </set>
        </property>
        
        <!-- 注入Map -->
        <property name="relation">
            <map>
                <!-- map的key和value引用其他类对象 <entry value-ref="" value-ref=""/> -->
                <entry key="father" value="zang"/>
                <entry key="mather" value="ma"/>
            </map>
        </property>
        
        <!-- 注入Properties -->
        <property name="identity">
            <props>
                <prop key="gender">male</prop>
                <prop key="hobby">readding</prop>
            </props>
        </property>
    </bean>
</beans>

 其中bean的scope属性默认为singleton，web项目中可以设置为request和session

4：测试程序

public class SpringTest {
    public static void main(String[] args) {
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        Person person = (Person)ac.getBean("person");
    }
}

 获得的Person对象所有属性都已经注入

5：Annotation配置

a.配置applicationContext.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:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
    <!-- 扫描的包 -->
    <context:component-scan base-package="test"/>
</beans>

b.配置实体

Address.java

@Scope("prototype")
@Component("address")
public class Address {
    @Value("address")
    private String address;

    public String getAddress() {
        return address;
    }
}

 Person.java

@Scope("prototype")
@Component
public class Person {
    
    @Value("zanglitao1")
    private String name;
    
    /**
     * @Autowired 默认byType
     * 当定义了多个相同类型的bean时，在@Autowired下使用@Qualifier("address")可以具体指定需要的bean
     * @Autowired(required = false) 未找到装配的类也不会报错
     */
    @Autowired
    @Qualifier("address")
    private Address address1;
    
    
    /**
     * @Resource 有name和type两个属性
     * @Resource 注释的 name 属性解析为 Bean 的名字，而 type 属性则解析为 Bean 的类型。
     * 所以如果使用 name 属性，则使用 byName 的自动注入策略，而使用 type 属性时则使用 byType 自动注入策略。
     * 如果既不指定 name 也不指定 type 属性，这时将通过反射机制使用 byName 自动注入策略
     */
    @Resource(name="address")
    private Address address2;
    
    //实体对象创建后调用
    @PostConstruct
    public void init() {
        System.out.println("init");
    }
    
    //实体对象摧毁前调用
    @PreDestroy
    public void destroy() {
        System.out.println("destroy");
    }
}