如何在spring中使用java enum作为bean
作者：互联网
我想实现的目标是为Spring托管bean注入枚举.
我不希望我的bean配置为XML(没有理由这样做除了这个不工作的枚举).
我有简单的maven项目：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>net.betlista</groupId>
<artifactId>test.spring.enum-injection</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>3.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>3.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.5.4</version>
</dependency>
<!-- testing -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>3.1.3.RELEASE</version>
<scope>test</scope>
</dependency>
</dependencies>
<properties>
<junit.version>4.11</junit.version>
</properties>
</project>
我创建了简单的测试
import net.betlista.spring.enum_injection.EnumInjectionComponent;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class TestClass {
@Autowired
EnumInjectionComponent component;
@Test
public void test() {
Assert.assertNotNull(component.roundingMode);
}
}
我的豆子是
package net.betlista.spring.enum_injection;
import java.math.RoundingMode;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
@Component
public class EnumInjectionComponent {
@Autowired
public RoundingMode roundingMode;
}
当我试图运行我的测试Ipm得到
java.lang.IllegalStateException: Failed to load ApplicationContext
at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:157)
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109)
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75)
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:321)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:211)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:288)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:290)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'enumInjectionComponent': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.math.RoundingMode net.betlista.spring.enum_injection.EnumInjectionComponent.roundingMode; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [java.math.RoundingMode] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:605)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:472)
at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:103)
at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:1)
at org.springframework.test.context.support.DelegatingSmartContextLoader.loadContext(DelegatingSmartContextLoader.java:228)
at org.springframework.test.context.TestContext.loadApplicationContext(TestContext.java:124)
at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:148)
... 24 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.math.RoundingMode net.betlista.spring.enum_injection.EnumInjectionComponent.roundingMode; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [java.math.RoundingMode] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:513)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:92)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
... 39 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [java.math.RoundingMode] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:948)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:817)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:731)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485)
... 41 more
但在日志中我可以看到：
INFO: Destroying singletons in
org.springframework.beans.factory.support.DefaultListableBeanFactory@236527f:
defining beans
[org.springframework.context.config.internalBeanConfigurerAspect,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,enumInjectionComponent,rounding,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor];
root of factory hierarchy
所以我在上下文中有舍入bean.
我错过了什么？
编辑：我刚刚发现,问题是只有Spring版本3.1.x,在3.2.x它可以工作,任何可用的解决方法？
edit2：这里是bean的定义
<?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:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
">
<context:spring-configured />
<context:annotation-config />
<context:component-scan base-package="net.betlista"/>
<bean id="rounding" class="java.math.RoundingMode" factory-method="valueOf">
<constructor-arg value="UP" />
</bean>
</beans>
EDIT3：
作为解决方法,我使用Dev Blanked的解决方法来指定列表,并在我的bean中使用@Value作为
@Value("#{roundingModes[0]}")
public RoundingMode roundingMode;
如果有一个更好(更好)的解决方案我想看到它;-)
解决方法:
应该可以提供裸枚举名称并指定值类型.下面是将舍入模式注入列表的示例.对于一个属性也应该是相同的.
<util:list id="roundingModes" value-type="java.math.RoundingMode">
<value>UP</value>
</util:list>
标签：java,spring,spring-3 来源： https://codeday.me/bug/20190703/1370883.html