【发布时间】：2019-05-18 10:00:01
【问题描述】：
在将 Spring Boot 应用程序从 Spring Boot 1.4.0 迁移到 Spring Boot 2 时，我开始在尝试从 .properties 文件中读取属性时遇到错误。
在属性文件中，属性定义为：
environment=dev
在我的一个课程中，我通过@Value 注释导入属性，如下所示：
@Getter
@Setter
public class CustomUserFilter extends SwitchUserFilter {
...
@Value("${environment}")
private String environment;
...
上面的类覆盖org.springframework.security.web.authentication.switchuser.SwitchUserFilter，使用户能够切换角色。
在 Spring Boot 1.4.0 之前，我能够在我的类中将此属性作为字符串导入。但是，自从迁移到 Spring Boot 2 后，我收到以下编译时错误：
错误:(43, 20) java: getEnvironment() in demo.config.CustomUserFilter 无法实现 getEnvironment() org.springframework.core.env.EnvironmentCapable 返回类型 java.lang.String 不兼容 org.springframework.core.env.Environment
我不确定为什么会这样。我也试过把这个变量的类型改成Environment (org.springframework.core.env.Environment)（如下图）：
...
@Value("${environment}")
private Environment environment;
...
，但后来我开始收到以下错误：
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'switchUserFilter': Unsatisfied dependency expressed through field 'environment'; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment': no matching editors or conversion strategy found
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:584)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:370)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1336)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204)
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:226)
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:182)
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:177)
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAdaptableBeans(ServletContextInitializerBeans.java:159)
at org.springframework.boot.web.servlet.ServletContextInitializerBeans.<init>(ServletContextInitializerBeans.java:81)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getServletContextInitializerBeans(ServletWebServerApplicationContext.java:261)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.selfInitialize(ServletWebServerApplicationContext.java:234)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:185)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:154)
... 52 more
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment': no matching editors or conversion strategy found
at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:77)
at org.springframework.beans.TypeConverterSupport.convertIfNecessary(TypeConverterSupport.java:60)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1089)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:581)
... 70 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment': no matching editors or conversion strategy found
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:299)
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:117)
at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:70)
... 74 more
有什么线索可以说明什么问题吗？我正在使用 Spring Boot 2.0、Spring 5、Java 11 和 Tomcat 8.5.35。谢谢！
【问题讨论】：
-
在类声明上方添加
@Configuration并检查它是否有效 -
Cannot convert value of type 'java.lang.String' to required type 'org.springframework.core.env.Environment'似乎您在问题中遗漏了几行重要的代码。 -
MaruthiAdithya 我已经定义了一个单独的@Configuration 类，我尝试在其中初始化上述类的一个bean。但是我也尝试在这个类中添加它，没有奏效。
-
@DoNhuVy 我所做的就是从
private String environment;更改为private Environment environment; -
如果更改属性名称会怎样？
标签： java spring spring-boot