Spring 级联属性
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Spring 级联属性是当两个bean 关联时 从一个bean 给 另一个bean 赋值
Application xml 配置如下
<bean id="ZhangSan" class="com.myth.springMVC.bean.Person">
<constructor-arg value="Zhangsan" index="0"></constructor-arg>
<constructor-arg value="male" index="1"></constructor-arg>
<!-- 可以用ref属性 建立bean之间的引用 -->
<constructor-arg ref="Europe" index="2"></constructor-arg>
<!-- 为级联属性赋值 -->
<property name="World.plainZone" value="NorthPole"></property>
</bean>
Person 类
public class Person {
private String name;
private String sex;
private World world;
//必须要有getter 和 setter 方法 如果通过Person给World 分类 使用Property 赋值的话
public void setWorld(World world) {
this.world = world;
}
public World getWorld() {
return world;
}
//构造器要跟XML 的构造方法匹配
public Person(String name, String sex, World world) {
super();
this.name = name;
this.sex = sex;
this.world = world;
}
@Override
public String toString() {
return "Person [name=" + name + ", sex=" + sex + ", world=" + world + "]";
}
}
World 类
package com.myth.springMVC.bean;
public class World {
// 大地
private String Plain;
// 大地区域
private String PlainZone;
// 风
private String Wind;
// 风速
private float WindSpeed;
//必须有Getter 和 Setter 方法 让world 获取PlainZone 属性
public void setPlainZone(String plainZone) {
this.PlainZone = plainZone;
}
public String getPlainZone() {
return PlainZone;
}
public World(String plain, String plainZone, String wind) {
super();
Plain = plain;
PlainZone = plainZone;
Wind = wind;
}
public World(String plain, String wind, float windSpeed) {
super();
Plain = plain;
Wind = wind;
WindSpeed = windSpeed;
}
@Override
public String toString() {
return "WorldBean [Plain=" + Plain + ", PlainZone=" + PlainZone + ", Wind=" + Wind + ", WindSpeed=" + WindSpeed
+ "]";
}
}
大部分的错误都是因为自己的马虎所导致的，所以在写配置文件的时候需要小心注意
遇到的错误：1） Bean property ‘Europe‘ is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?
可以看到Europe 是一个读不到的Bean Europe 是World 的一个实例化 ， 这里应该使用World 而不是Europe
八月 10, 2017 6:30:54 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org[email protected]300ffa5d: startup date [Thu Aug 10 18:30:54 CST 2017]; root of context hierarchy
八月 10, 2017 6:30:54 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [applicationContext.xml]
八月 10, 2017 6:30:55 下午 org.springframework.context.support.ClassPathXmlApplicationContext refresh
警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException:
Error creating bean with name ‘ZhangSan‘ defined in class path resource [applicationContext.xml]: Error setting property values;
nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property ‘Europe.plainZone‘ of bean class [com.myth.springMVC.bean.Person]:
Nested property in path ‘Europe.plainZone‘ does not exist; nested exception is org.springframework.beans.NotReadablePropertyException:
Invalid property ‘Europe‘ of bean class [com.myth.springMVC.bean.Person]: Bean property ‘Europe‘ is not readable or has an invalid getter method:
Does the return type of the getter match the parameter type of the setter?
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘ZhangSan‘ defined in class path resource [applicationContext.xml]: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property ‘Europe.plainZone‘ of bean class [com.myth.springMVC.bean.Person]: Nested property in path ‘Europe.plainZone‘ does not exist; nested exception is org.springframework.beans.NotReadablePropertyException: Invalid property ‘Europe‘ of bean class [com.myth.springMVC.bean.Person]: Bean property ‘Europe‘ is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1568)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1276)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.myth.springMVC.test.HelloMain.main(HelloMain.java:21)
Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property ‘Europe.plainZone‘ of bean class [com.myth.springMVC.bean.Person]: Nested property in path ‘Europe.plainZone‘ does not exist; nested exception is org.springframework.beans.NotReadablePropertyException: Invalid property ‘Europe‘ of bean class [com.myth.springMVC.bean.Person]: Bean property ‘Europe‘ is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?
at org.springframework.beans.AbstractNestablePropertyAccessor.setPropertyValue(AbstractNestablePropertyAccessor.java:273)
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:95)
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:75)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1564)
... 13 more
Caused by: org.springframework.beans.NotReadablePropertyException: Invalid property ‘Europe‘ of bean class [com.myth.springMVC.bean.Person]: Bean property ‘Europe‘ is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?
at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:633)
at org.springframework.beans.AbstractNestablePropertyAccessor.getNestedPropertyAccessor(AbstractNestablePropertyAccessor.java:850)
at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyAccessorForPropertyPath(AbstractNestablePropertyAccessor.java:827)
at org.springframework.beans.AbstractNestablePropertyAccessor.setPropertyValue(AbstractNestablePropertyAccessor.java:270)
... 16 more
2）Bean ‘ZhangSan‘; nested exception is org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: <property> element for property ‘Europe.plainZone‘ must specify a ref or value
构造器的方法没有匹配，可以看构造器 的方法
八月 10, 2017 5:52:24 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org[email protected]300ffa5d: startup date [Thu Aug 10 17:52:24 CST 2017]; root of context hierarchy
八月 10, 2017 5:52:24 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [applicationContext.xml]
Exception in thread "main" org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unexpected failure during bean definition parsing
Offending resource: class path resource [applicationContext.xml]
Bean ‘ZhangSan‘; nested exception is org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: <property> element for property ‘Europe.plainZone‘ must specify a ref or value
Offending resource: class path resource [applicationContext.xml]
Bean ‘ZhangSan‘
-> Property ‘Europe.plainZone‘
at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:70)
at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:85)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.error(BeanDefinitionParserDelegate.java:308)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseBeanDefinitionElement(BeanDefinitionParserDelegate.java:562)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseBeanDefinitionElement(BeanDefinitionParserDelegate.java:460)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseBeanDefinitionElement(BeanDefinitionParserDelegate.java:429)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.processBeanDefinition(DefaultBeanDefinitionDocumentReader.java:299)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseDefaultElement(DefaultBeanDefinitionDocumentReader.java:190)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:169)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:142)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:94)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:508)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:392)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:336)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:304)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:181)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:217)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:252)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:127)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:93)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:129)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:614)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:515)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.myth.springMVC.test.HelloMain.main(HelloMain.java:21)
Caused by: org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: <property> element for property ‘Europe.plainZone‘ must specify a ref or value
Offending resource: class path resource [applicationContext.xml]
Bean ‘ZhangSan‘
-> Property ‘Europe.plainZone‘
at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:70)
at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:85)
at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:80)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.error(BeanDefinitionParserDelegate.java:301)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parsePropertyValue(BeanDefinitionParserDelegate.java:1000)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parsePropertyElement(BeanDefinitionParserDelegate.java:894)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parsePropertyElements(BeanDefinitionParserDelegate.java:755)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseBeanDefinitionElement(BeanDefinitionParserDelegate.java:547)
... 23 more
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