[英]Trouble passing constructor-arg in Spring
我在使用Spring将一个Constructor-arg传递到我的Project时遇到了一些麻烦。 我敢肯定这是微不足道的,但我仍在尝试学习Spring。 我的代码在这里:
package com.WheelOfFortune.Client;
import java.util.ArrayList;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;
import org.springframework.stereotype.Controller;
@Controller
public class Spinner implements SpinnerInterface{
private int balance;
private String vacation;
private String car;
private ArrayList<String> spinWheel;
//Methods can access same instance of factory
BeanFactory factory = new XmlBeanFactory(new FileSystemResource(
"src/main/resources/spring/SpinWheel.xml"));
public Spinner(){}
@Autowired
public Spinner(int balance, String vacation, String car, ArrayList<String> spinWheel)
{
this.balance = balance;
this.vacation = vacation;
this.car = car;
this.spinWheel = spinWheel;
}
//Setters and Getters
public void setSpinWheel()
{
this.spinWheel = spinWheel;
}
public ArrayList<String> getSpinWheel(ArrayList<String> getSpinWheel)
{
return spinWheel;
}
public void setBalance()
{
this.balance = balance;
}
public void setVacation()
{
this.vacation = vacation;
}
public void setCar()
{
this.car = car;
}
public int getBalance(int balance)
{
return balance;
}
public String getVacation(String vacation)
{
return vacation;
}
public String getCar(String car)
{
return car;
}
public void spin() {
Spinner spin = (Spinner) factory.getBean("spinWheel");
}
public void addToBank(boolean isCorrect) {
// TODO Auto-generated method stub
}
public void deductFromBank() {
// TODO Auto-generated method stub
}
public void vacation(boolean isCorrect) {
Spinner vacation = (Spinner) factory.getBean("vacation");
System.out.println(vacation);
}
public void car(boolean isCorrect){
Spinner car = (Spinner) factory.getBean("car");
}
}
和我的xml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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="balance" class="com.WheelOfFortune.Client.Spinner">
<constructor-arg>
<value>0</value>
</constructor-arg>
</bean>
<bean id="vacation" class="com.WheelOfFortune.Client.Spinner">
<constructor-arg value="You Won a Trip to Hawaii!!" />
</bean>
<bean id="car" class="com.WheelOfFortune.Client.Spinner">
<constructor-arg value="You Won a brand new Corvette!!" />
</bean>
<bean id="spinWheel" class="com.WheelOfFortune.Client.Spinner">
<property name="word">
<list>
<value>$100</value>
<value>$150</value>
<value>$275</value>
<value>$400</value>
<value>$500</value>
<value>$750</value>
<value>$1000</value>
<value>Bankruptcy</value>
<value>$5000</value>
<value>Vacation</value>
<value>Car</value>
</list>
</property>
</bean>
</beans>
每当我尝试运行项目时,总会得到它作为stacktrace:
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vacation' defined in file [/home/ryan/workspace/wheel/src/main/resources/spring/SpinWheel.xml]: Could not resolve matching constructor (hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:250)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1003)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:907)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
at com.WheelOfFortune.Client.Spinner.vacation(Spinner.java:74)
at com.WheelOfFortune.Client.Client.main(Client.java:10)
我已经在XML文件上上下浮动,找不到任何原因会产生此stacktrace。 有什么建议么?
您的配置中有很多错误的地方。
首先,关于您的constructor-arg
问题,您在XML中使用了一个arg构造函数:
<bean id="balance" class="com.WheelOfFortune.Client.Spinner">
<constructor-arg>
<value>0</value>
</constructor-arg>
</bean>
但是您的Java仅使用4个args定义此构造函数:
public Spinner(int balance, String vacation, String car, ArrayList<String> spinWheel);
您可以写的是:
<bean id="spinner" class="com.WheelOfFortune.Client.Spinner">
<constructor-arg>
<value>0</value>
</constructor-arg>
<constructor-arg ref="vacation">
...
</bean>
但是在您需要更正vacation
bean之前(与car
和spinWheel
相同)。 您将其键入为com.WheelOfFortune.Client.Spinner
但这是一个String
。
最终 ,您将混合注释和XML配置。 这不是问题,但是在启动Spring时可能会造成混淆,我建议要么全部使用XML要么全部使用注释。
如果您需要更多详细信息,请随时询问;)
编辑 :重新阅读您的文章,我实际上了解您要写的内容,并且如果您激活组件扫描,仅更正bean的类型可能就足够了。
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