Spring Bean

一、获取Bean

spring-config.xml

<bean id="myBean" class="com.lzp.mySpring.MyBean"/>

 Main.java

ApplicationContext context =
new ClassPathXmlApplicationContext("spring-config.xml");

MyBean myBean = (MyBean) context.getBean("myBean");

二、构造函数

MyBean2.java

public class MyBean2 {
    
    private MyBean myBean;
    
    public MyBean getMyBean() {
        return myBean;
    }

    public void setMyBean(MyBean myBean) {
        this.myBean = myBean;
    }

    private int intProperty;

    public int getIntProperty() {
        return intProperty;
    }

    public void setIntProperty(int intProperty) {
        this.intProperty = intProperty;
    }

    public MyBean2(int intProperty,MyBean myBean) {
        this.intProperty = intProperty;
        this.myBean=myBean;
        
    }
}

spring-config.xml

 <bean id="myBean2" class="com.lzp.mySpring.MyBean2">
         <constructor-arg value="12"></constructor-arg>
         <constructor-arg type="com.lzp.mySpring.MyBean" ref="myBean"></constructor-arg>
     </bean>

三、静态工厂方法

FactoryMethodBean.java

public class FactoryMethodBean {
    private FactoryMethodBean() {
    }

    private static class InnerClass {
        static FactoryMethodBean instance = new FactoryMethodBean();
    }

    public static FactoryMethodBean getInstance() {
        return InnerClass.instance;

    }
}

spring-config.xml

<bean id="factoryMethodBean" class="com.lzp.mySpring.FactoryMethodBean" factory-method="getInstance"></bean>

 四、Bean声明周期

singleton 单例（默认）

prototype每次实例化都需要实例

request单请求 session　global-session　 session基于web

五、初始化和销毁

spring-config.xml

   <!-- 注意这句话，如果是singleton或者没有该句（默认情况）时，才会执行destroy-method指定的方法，如果是当前的prototype不会触发destroymethod的执行 -->

<bean id="myBean" class="com.lzp.mySpring.MyBean" init-method="init" destroy-method="destroy" />

MyBean.java

public class MyBean {
    public void init(){System.out.println("init");}
    public void destroy(){System.out.println("destroy");}
}

 Main.java

public static void main(String[] args) {
        // TODO Auto-generated method stub
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
        MyBean myBean = (MyBean) context.getBean("myBean");
        
         
         ((ClassPathXmlApplicationContext) context).close();
　　　　　　//加上close才能调用destroy方法
    }

六、属性装配

属性装配和构造状态类似，除此之外多出了一种p标签,p标签比较简洁,spring2.5之后可用

spring-config

xmlns:p="http://www.springframework.org/schema/p" 需要自行添加

<bean id="myBean3" class="com.lzp.mySpring.MyBean3">
        <property name="simpleProperty" value="12"></property>
        <property name="myBean" ref="myBean"></property>
        <property name="list">
            <list>
                <ref bean="myBean" />
            </list>
        </property>
        <property name="map">
            <map>
                <entry key="one" value-ref="myBean"></entry>
            </map>
        </property>
        <property name="set">
            <set>
                <ref bean="myBean" />
            </set>
        </property>
        <property name="properties">
            <props>
                <prop key="a">a</prop>
            </props>
        </property>
    </bean>

MyBean3.java

public class MyBean3 {
     private Integer simpleProperty;

    public Integer getSimpleProperty() {
        return simpleProperty;
    }

    public void setSimpleProperty(Integer simpleProperty) {
        this.simpleProperty = simpleProperty;
    }
    private MyBean myBean;

    public MyBean getMyBean() {
        return myBean;
    }

    public void setMyBean(MyBean myBean) {
        this.myBean = myBean;
    }
    
    private ArrayList<MyBean> list;
    private HashMap<String,MyBean> map;
    public ArrayList<MyBean> getList() {
        return list;
    }

    public void setList(ArrayList<MyBean> list) {
        this.list = list;
    }

    public HashMap<String, MyBean> getMap() {
        return map;
    }

    public void setMap(HashMap<String, MyBean> map) {
        this.map = map;
    }

    public HashSet<MyBean> getSet() {
        return set;
    }

    public void setSet(HashSet<MyBean> set) {
        this.set = set;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }
    private HashSet<MyBean> set;
    private Properties properties;
    
}