无法解析某些属性的占位符

Question

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dbDataSource' defined in cz.ita.javaee.config.DatabaseConfiguration: Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'db.jndi' in value "${db.jndi}" at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:518) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=14=](AbstractBeanFactory.java:312) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:756) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:409) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:291) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4743) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5207) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1739) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) at javax.management.remote.rmi.RMIConnectionImpl.access0(RMIConnectionImpl.java:76) at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401) at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357) at sun.rmi.transport.Transport.run(Transport.java:200) at sun.rmi.transport.Transport.run(Transport.java:197) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:196) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run[=14=](TCPTransport.java:683) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'db.jndi' in value "${db.jndi}" at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:172) at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties[=14=](PropertySourcesPlaceholderConfigurer.java:175) at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:834) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1081) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1060) at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:809) at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:715) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:458) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1249) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1098) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) ... 55 more

我的数据库配置class:

@EnableTransactionManagement
public class DatabaseConfiguration {

    @Bean(name = "dbDataSource")
    @Profile("!development")
    public DataSource dataSource(@Value("${db.jndi}") String dbJndiName) {
        JndiDataSourceLookup lookup = new JndiDataSourceLookup();
        return lookup.getDataSource(dbJndiName);
    }

    @Profile("development")
    public DataSource dataSource(@Value("${development.db.driver}") String dbDriver,
            @Value("${development.db.url}") String dbUrl,
            @Value("${development.db.username}") String dbUsername,
            @Value("${development.db.password}") String dbPassword) {
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource(dbUrl);
        driverManagerDataSource.setDriverClassName(dbDriver);
        driverManagerDataSource.setUsername(dbUsername);
        driverManagerDataSource.setPassword(dbPassword);
        return driverManagerDataSource;
    }

}

和 AppConfig：

@Import({DatabaseConfiguration.class, MailSenderConfiguration.class})
public class AppConfig {
@Bean
public PropertyPlaceholderConfigurer propertyPlaceholderConfigurer() {
    PropertyPlaceholderConfigurer propertyPlaceholderConfigurer = new PropertyPlaceholderConfigurer();
    propertyPlaceholderConfigurer.setLocation(new ClassPathResource("application.properties"));
    propertyPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(true);
    return propertyPlaceholderConfigurer;
}

}

你好，我遇到了上面的错误，我不知道如何解决，你能帮我吗？在我添加这个 bean 之前，我的项目工作正常：

@PropertySource("classpath:mail.properties")
public class MailSenderConfiguration {

@Value("${mail.smtp.host}")
private String mailHost;

@Value("${mail.smtp.port}")
private int mailPort;

@Value("${mail.username}")
private String mailUsername;

@Value("${mail.password}")
private String mailPassword;

@Value("${mail.protocol}")
private String mailProtocol;

@Value("${mail.smtp.auth}")
private boolean mailAuth;

@Value("${mail.smtp.starttls.enable}")
private String mailEnableTls;

@Value("${mail.smtp.debug}")
private boolean mailDebug;

@Bean
public JavaMailSender getMailSender() {
    JavaMailSenderImpl mailSender = new JavaMailSenderImpl();

    mailSender.setHost(mailHost);
    mailSender.setPort(mailPort);
    mailSender.setUsername(mailUsername);
    mailSender.setPassword(mailPassword);

    Properties mailProperties = new Properties();
    mailProperties.put("mail.transport.protocol", mailProtocol);
    mailProperties.put("mail.smtp.auth", mailAuth);
    mailProperties.put("mail.smtp.starttls.enable", mailEnableTls);
    mailProperties.put("mail.smtp.debug", mailDebug);
    mailSender.setJavaMailProperties(mailProperties);

    return mailSender;
}

@Bean
public PropertyPlaceholderConfigurer propertyPlaceholderConfigurer() {
    PropertyPlaceholderConfigurer propertyPlaceholderConfigurer = new PropertyPlaceholderConfigurer();
    propertyPlaceholderConfigurer.setLocation(new ClassPathResource("mail.properties"));
    propertyPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(true);
    return propertyPlaceholderConfigurer;
}

}

Answer 1

在尝试通过使 bean 静态化来评估属性之前，您应该确保 PropertyPlaceholderConfigurer bean 已加载。 Spring 在其他 bean 定义之前实例化静态 bean。

@Import({DatabaseConfiguration.class, MailSenderConfiguration.class})
public class AppConfig {
@Bean
public static PropertyPlaceholderConfigurer propertyPlaceholderConfigurer() {
    PropertyPlaceholderConfigurer propertyPlaceholderConfigurer = new PropertyPlaceholderConfigurer();
    propertyPlaceholderConfigurer.setLocation(new ClassPathResource("application.properties"));
    propertyPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(true);
    return propertyPlaceholderConfigurer;
}

Answer 2

看起来您的属性 MailSenderConfiguration 中的源配置覆盖了 AppConfig 中的配置。

您可以从 MailSenderConfiguration 中删除 PropertyPlaceholderConfigurer bean，并在 AppConfig 中为 "mail.properties" 设置额外的位置（使用 setLocations() 方法而不是 setLocation()）：

@Import({DatabaseConfiguration.class, MailSenderConfiguration.class})
public class AppConfig {
@Bean
public PropertyPlaceholderConfigurer propertyPlaceholderConfigurer() {
    PropertyPlaceholderConfigurer propertyPlaceholderConfigurer = new PropertyPlaceholderConfigurer();
    propertyPlaceholderConfigurer.setLocations(new ClassPathResource("application.properties"), new ClassPathResource("mail.properties"));
    propertyPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(true);
    return propertyPlaceholderConfigurer;
}

无法解析某些属性的占位符

Could not resolve placeholder for some property

java

spring

javabeans

无法解析某些 属性 的占位符

Could not resolve placeholder for some property

java

spring

javabeans

无法解析某些属性的占位符