Spring知识整理

Bean生命周期

@Component
public class BeanTest implements BeanFactoryAware, BeanNameAware,
        InitializingBean, DisposableBean {

    private String name;
    private String address;
    private int phone;

    private BeanFactory beanFactory;
    private String beanName;

    public BeanTest() {
        System.out.println("【构造器】调用Person的构造器实例化");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        System.out.println("【注入属性】注入属性name");
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        System.out.println("【注入属性】注入属性address");
        this.address = address;
    }

    public int getPhone() {
        return phone;
    }

    public void setPhone(int phone) {
        System.out.println("【注入属性】注入属性phone");
        this.phone = phone;
    }

    @Override
    public String toString() {
        return "Person [address=" + address + ", name=" + name + ", phone="
                + phone + "]";
    }

    // 这是BeanFactoryAware接口方法
    @Override
    public void setBeanFactory(BeanFactory arg0) throws BeansException {
        System.out
                .println("【BeanFactoryAware接口】调用BeanFactoryAware.setBeanFactory()");
        this.beanFactory = arg0;
    }

    // 这是BeanNameAware接口方法
    @Override
    public void setBeanName(String arg0) {
        System.out.println("【BeanNameAware接口】调用BeanNameAware.setBeanName()"+arg0);
        this.beanName = arg0;
    }

    // 这是InitializingBean接口方法
    @Override
    public void afterPropertiesSet() throws Exception {
        System.out
                .println("【InitializingBean接口】调用InitializingBean.afterPropertiesSet()");
    }

    // 这是DiposibleBean接口方法
    @Override
    public void destroy() throws Exception {
        System.out.println("【DiposibleBean接口】调用DiposibleBean.destory()");
    }

    // 通过<bean>的init-method属性指定的初始化方法
    public void myInit() {
        System.out.println("【init-method】调用<bean>的init-method属性指定的初始化方法");
    }

    // 通过<bean>的destroy-method属性指定的初始化方法
    public void myDestory() {
        System.out.println("【destroy-method】调用<bean>的destroy-method属性指定的初始化方法");
    }

}

BeanPostProcessor.postProcessBeforeInitialization，应用BeanPostProcessor在所有Bean初始化之前进行调用方法。

BeanPostProcessor.postProcessAfterInitialization，应用BeanPostProcessor在所有Bean初始化之后进行调用方法。

@Component
public class BeanPostProcessorTest implements BeanPostProcessor {


    public BeanPostProcessorTest() {
        super();
        System.out.println("这是BeanPostProcessor实现类构造器！！");
    }

    @Override
    public Object postProcessAfterInitialization(Object arg0, String arg1)
            throws BeansException {
        if (arg0 instanceof BeanTest) {
            System.out
                    .println("BeanPostProcessor接口方法postProcessAfterInitialization对属性进行更改！");
        }
        return arg0;
    }

    @Override
    public Object postProcessBeforeInitialization(Object arg0, String arg1)
            throws BeansException {
        if (arg0 instanceof BeanTest) {
            System.out
                    .println("BeanPostProcessor接口方法postProcessBeforeInitialization对属性进行更改！");
        }
        return arg0;
    }

}

Autowired注解

1. 默认按照类型去容器中找
2. 若存在多个类型，则通过属性名作为ID去容器中找