[TOC]

BeansException的子接口

异样类型触发条件(举例)场景举例
NoSuchBeanDefinitionException当查找 Bean 不存在于 IoC 容器时BeanFactory#getBean ObjectFactory#getObject
NoUniqueBeanDefinitionException类型依赖查找时，IoC 容器存在多 个 Bean 实例BeanFactory#getBean(Class)
BeanInstantiationException当 Bean 所对应的类型非具体类时BeanFactory#getBean
BeanCreationException当 Bean 初始化过程中Bean 初始化办法执行异样 时
BeanDefinitionStoreException当 BeanDefinition 配置元信息非法 时XML 配置资源无奈关上时

Rumenz.java实体类

package com.rumenz;import org.springframework.beans.factory.InitializingBean;public class Rumenz implements InitializingBean {    private Integer id;    private String name;    @Override    public void afterPropertiesSet() throws Exception {        throw new Exception("初始化异样。。。。");    }    @Override    public String toString() {        return "Rumenz{" +                "id=" + id +                ", name='" + name + '\'' +                '}';    }    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

NoSuchBeanDefinitionException不存在要查找的Bean

package com.rumenz;import java.util.Map;public class DemoApplication {    public static void main(String[] args) {         AnnotationConfigApplicationContext ac=new AnnotationConfigApplicationContext();         ac.register(DemoApplication.class); //不注册Rumenz         ac.refresh();         //NoSuchBeanDefinitionException不存在要查找的Bean         byBeanFactory(ac);         ac.close();    }     //NoSuchBeanDefinitionException不存在要查找的Bean    private static void byBeanFactory(AnnotationConfigApplicationContext ac) {        ac.getBean(Rumenz.class);    }}

输入

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.rumenz.Rumenz' available

NoUniqueBeanDefinitionException 容器中存在多个同类型的Bean

配置Bean的

注册了两个Rumenz
package com.rumenz;import org.springframework.context.annotation.Bean;public class Config {    @Bean    public Rumenz rumenz1(){        Rumenz r=new Rumenz();        r.setId(456);        r.setName("入门小站");        return r;    }    @Bean    public Rumenz rumenz(){        Rumenz r=new Rumenz();        r.setId(123);        r.setName("入门小站");        return r;    }}

案例

package com.rumenz;import org.springframework.beans.factory.ObjectProvider;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import java.util.Map;public class DemoApplication {    public static void main(String[] args) {         AnnotationConfigApplicationContext ac=new AnnotationConfigApplicationContext();         ac.register(Config.class); //注册Rumenz         ac.refresh();         // NoUniqueBeanDefinitionException要查找的Bean不惟一         byBeanFactory(ac);         ac.close();    }     // NoUniqueBeanDefinitionException要查找的Bean不惟一    private static void byBeanFactory(AnnotationConfigApplicationContext ac) {        ac.getBean(Rumenz.class);    }}

输入

Exception in thread "main" org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'com.rumenz.Rumenz' available: expected single matching bean but found 2: rumenz1,rumenz

BeanInstantiationException不能被实例化

package com.rumenz;public class DemoApplication {    public static void main(String[] args) {         AnnotationConfigApplicationContext ac=new AnnotationConfigApplicationContext();         BeanDefinitionBuilder bb=BeanDefinitionBuilder.genericBeanDefinition(BeanFactory.class);         ac.registerBeanDefinition("err",bb.getBeanDefinition());         ac.refresh();         ac.close();    }}

输入

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.beans.factory.BeanFactory]: Specified class is an interface

BeanCreationException Bean初始化异样

package com.rumenz;import org.springframework.beans.factory.BeanFactory;import org.springframework.beans.factory.FactoryBean;import org.springframework.beans.factory.ObjectProvider;import org.springframework.beans.factory.support.BeanDefinitionBuilder;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import java.util.Map;public class DemoApplication {    public static void main(String[] args) {         AnnotationConfigApplicationContext ac=new AnnotationConfigApplicationContext();         // 4.BeanCreationException Bean初始化异样         BeanDefinitionBuilder bb=BeanDefinitionBuilder.genericBeanDefinition(Rumenz.class);         ac.registerBeanDefinition("err",bb.getBeanDefinition());         ac.refresh();         ac.close();    }}

BeanDefinitionStoreException 配置元谬误

Beanss.xml 不存在就会触发BeanDefinitionStoreException
ApplicationContext acc=new ClassPathXmlApplicationContext("Beanss.xml");

输入

Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [Beanss.xml]; nested exception is java.io.FileNotFoundException: class path resource [Beanss.xml] cannot be opened because it does not exist