我目前正在做春季新手教程,似乎我有一樣的人一樣喜歡使本教程的人,但我不斷得到錯誤NullPointerException
,有人可以幫助我嗎?爪哇春天AutoWire byName
如果取消註釋,我的xml文件中有部分是註釋的,程序將起作用。但沒有它,當我嘗試使用autowire byName它不起作用。
主類:
public class MainSpring {
public static void main(String[] args) {
ApplicationContext context= new ClassPathXmlApplicationContext("konfiguracja.xml");
SomeBean bean = context.getBean("SomeBean",SomeBean.class);
System.out.println(bean.getInjectedBean1().getName());
System.out.println(bean.getInjectedBean2().getName());
}
}
InjectedBean類
package springTutorial;
public class InjectedBean {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
SomeBean類
import org.springframework.beans.factory.annotation.Autowired;
public class SomeBean {
private InjectedBean InjectedBean1;
private InjectedBean InjectedBean2;
public InjectedBean getInjectedBean1() {
return InjectedBean1;
}
public void setInjectedBean1(InjectedBean injectedBean1) {
this.InjectedBean1 = injectedBean1;
}
public InjectedBean getInjectedBean2() {
return InjectedBean2;
}
public void setInjectedBean2(InjectedBean injectedBean2) {
this.InjectedBean2 = injectedBean2;
}
}
configuration.xml文件文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:c="http://www.springframework.org/schema/c"
xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd">
<bean id="InjectedBean1" class="springTutorial.InjectedBean" >
<property name="name" value="asasa" >
</property>
</bean>
<bean id="InjectedBean2" class="springTutorial.InjectedBean" >
<property name="name" value="vbvb">
</property>
</bean>
<bean id="SomeBean" class="springTutorial.SomeBean" autowire="byName" >
<!-- <property name="injectedBean1"> -->
<!-- <ref bean="InjectedBean1"/> -->
<!-- </property> -->
<!-- <property name="injectedBean2"> -->
<!-- <ref bean="InjectedBean2"/> -->
<!-- </property> -->
</bean>
</beans>
分別將您的bean id更改爲'injectBean1'和'injectedBean2'。 –
歡迎來到Stack Overflow。請指出在IDE下運行時出現錯誤的位置。 –
它的工作原理,謝謝你的幫助,我祝你好日子:) – Ravencrest1985