Question

将Spring Boot应用程序从Spring Boot 1.4.0迁移到Spring Boot 2时，在尝试从.properties文件读取属性时开始出现错误。

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;
    ...

上面的类重写org.springframework.security.web.authentication.switchuser.SwitchUserFilter，以使用户能够切换角色。

在Spring Boot 1.4.0之前，我可以将这个属性作为String导入我的课程中。但是，自从迁移到Spring Boot 2之后，我得到了以下编译时错误：

错误：（43，20）java：demo.config.CustomUserFilter中的getEnvironment（）无法在中实现getEnvironment（） org.springframework.core.env.EnvironmentCapable返回类型 java.lang.String与不兼容 org.springframework.core.env.Environment

我不确定为什么会这样。我还尝试将此变量的类型更改为Environment (org.springframework.core.env.Environment)（如下所示）：

...
@Value("${environment}")
private Environment environment;
...

，但随后我开始出现以下错误：

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

关于可能出什么问题的任何线索？我正在使用 Spring Boot 2.0 ， Spring 5 ， Java 11 和 Tomcat 8.5.35 。谢谢！

Answer 1

问题与Spring Boot无关。我上面的课程扩展了org.springframework.security.web.authentication.switchuser.SwitchUserFilter，并进一步扩展了org.springframework.web.filter.GenericFilterBean。该GenericFilterBean类还具有属性private Environment environment;。此外，该类在Spring 5版本中进行了修改，以在此属性上包含getter方法。春季5在类getEnvironment()中引入了一个返回类型为Environment的{{1}}，它与我的返回类型为GenericFilterBean的{{1}}冲突。

为避免发生这种冲突，我只是将属性名称从getEnvironment()更改为String，然后事情就解决了。

Answer 2

将@Component添加到您的班级并尝试

Spring Boot 2无法将属性读取为字符串

2 个答案: