這篇文章帶給大家的內容是關於Spring源碼之BeanDefinition類的詳細介紹，有一定的參考價值，有需要的朋友可以參考一下，希望對你有所幫助。
Spring版本為5.1.5
用過spring的人都知道，我們將物件注入到spring容器中，交給spring來幫我們管理。這種對像我們稱為bean對象。但是這些bean物件在spring容器中，到底是以什麼形式存在，具有哪些屬性、行為呢？今天我們進入到spring源碼來一探究竟。
bean的創建工廠BeanFactory有個預設實作類別DefaultListableBeanFactory，內部有個存放所有註入bean物件資訊的Map
/** Map of bean definition objects, keyed by bean name. */ private final Map<String, BeanDefinition> beanDefinitionMap = new ConcurrentHashMap<>(256);
Map的value物件BeanDefinition就是spring中對bean的定義與描述，具體概述如下：
| 屬性 | 行為 | 解釋 |
|---|---|---|
| parentName | String getParentName(); void setParentName(@Nullable String parentName); |
bean定義物件的父類別定義物件名稱 |
| #beanClassName | String getBeanClassName(); void setBeanClassName(@Nullable String beanClassName); |
bean物件的實際類別類別 |
| scope | String getScope(); void setScope(@Nullable String scope); |
bean物件是否為單例 |
| lazyInit | boolean isLazyInit(); void setLazyInit(boolean lazyInit); |
是否懶載入 |
| dependsOn | String[] getDependsOn(); void setDependsOn(@Nullable String... dependsOn); |
設定依賴的bean對象，被依賴的bean物件總是會比目前bean物件先建立 |
| autowireCandidate | boolean isAutowireCandidate(); void setAutowireCandidate(boolean autowireCandidate); |
設定是否可以自動注入。只對@Autowired註解有效，設定檔中可以透過property顯示注入 |
| #primary | boolean isPrimary(); void setPrimary(boolean primary); |
配置bean為主要候選bean。當同一個介面的多個實作類別或一個類別多次注入spring容器時，透過該屬性來配置某個bean為主候選bean，透過型別來注入時，預設為使用主候選bean注入 |
| factoryBeanName | String getFactoryBeanName(); void setFactoryBeanName(@Nullable String factoryBeanName); |
設定建立bean的工廠名稱 |
public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
/**
* Override the target scope of this bean, specifying a new scope name.
* @see #SCOPE_SINGLETON
* @see #SCOPE_PROTOTYPE
*/
void setScope(@Nullable String scope);
/**
* Return the name of the current target scope for this bean,
* or {@code null} if not known yet.
*/
@Nullable
String getScope();
}package com.yuanweiquan.learn.bean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Description;
public class MyTestBean {
@Autowired
private AutowireCandidateBean autowireCandidateBean;
public void init() {
System.out.println("inti MyTestBean");
}
public AutowireCandidateBean getAutowireCandidateBean() {
return autowireCandidateBean;
}
public void setAutowireCandidateBean(AutowireCandidateBean bean) {
this.autowireCandidateBean = bean;
}
}package com.yuanweiquan.learn.bean;
public class AutowireCandidateBean {
public void initBean() {
System.out.println("init AutowireCandidateBean");
}
public void destroyBean() {
System.out.println("destroy AutowireCandidateBean");
}
} <bean id="myTestBean" class="com.yuanweiquan.learn.bean.MyTestBean"
depends-on="autowireCandidateBean"
init-method="init"/>
<bean id="autowireCandidateBean"
class="com.yuanweiquan.learn.bean.AutowireCandidateBean"
init-method="initBean"
autowire-candidate="true"
destroy-method="destroyBean"
scope="singleton"
parent="myTestBean"
lazy-init="default"
primary="true">
<description>autowireCandidateBean description</description>
</bean>FileSystemXmlApplicationContext factory =
new FileSystemXmlApplicationContext("classpath:applicationContext.xml");
BeanDefinition myTestBeanDefinition =
factory.getBeanFactory().getBeanDefinition("autowireCandidateBean");
//输出
System.out.println("bean description:" + myTestBeanDefinition.getDescription());
System.out.println("bean class name:" + myTestBeanDefinition.getBeanClassName());
System.out.println("parent name:" + myTestBeanDefinition.getParentName());
System.out.println("scope:" + myTestBeanDefinition.getScope());
System.out.println("is lazyinit:" + myTestBeanDefinition.isLazyInit());
System.out.println("depends On:" + myTestBeanDefinition.getDependsOn());
System.out.println("is autowireCandidate:" + myTestBeanDefinition.isAutowireCandidate());
System.out.println("is primary:" + myTestBeanDefinition.isPrimary());
System.out.println("factory bean name:"+myTestBeanDefinition.getFactoryBeanName());
System.out.println("factory bean method name:" + myTestBeanDefinition.getFactoryMethodName());
System.out.println("init method name:" + myTestBeanDefinition.getInitMethodName());
System.out.println("destory method name:" + myTestBeanDefinition.getDestroyMethodName());
System.out.println("role:" + myTestBeanDefinition.getRole());
//关闭context，否则不会调用bean的销毁方法
factory.close();init AutowireCandidateBean inti MyTestBean bean description:autowireCandidateBean description bean class name:com.yuanweiquan.learn.bean.AutowireCandidateBean parent name:myTestBean scope:singleton is lazyinit:false depends On:null is autowireCandidate:true is primary:true factory bean name:null factory bean method name:null init method name:initBean destory method name:destroyBean role:0 destroy AutowireCandidateBean
以上是Spring源碼之BeanDefinition類別的詳細介紹的詳細內容。更多資訊請關注PHP中文網其他相關文章！
