java 无法解析某些属性的占位符

Could not resolve placeholder for some property

提问by Denis Stephanov

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$0(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.access$300(RMIConnectionImpl.java:76) at javax.management.remote.rmi.RMIConnectionImpl$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$1.run(Transport.java:200) at sun.rmi.transport.Transport$1.run(Transport.java:197) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:196) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport$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$0(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

org.springframework.beans.factory.BeanCreationException：在 cz.ita.javaee.config.DatabaseConfiguration 中定义名称为“dbDataSource”的 bean 创建时出错：bean 创建过程中出现意外异常；嵌套异常是 java.lang.IllegalArgumentException：无法在 org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:518) 处解析值“${db.jndi}”中的占位符“db.jndi” org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312) 在 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) 在 org.springframework.beans .factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:

My Database Configuration class:

我的数据库配置类：

@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;
    }

}

And AppConfig:

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;
}

}

}

Hi, I got error above and I don't know how to fix it, can you help me? My project working fine until I've added this bean:

你好，我上面有错误，我不知道如何解决它，你能帮我吗？我的项目工作正常，直到我添加了这个 bean：

@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;
}

}

}

回答by elyor

Looks like your property source config in MailSenderConfiguration is overriding the one in AppConfig.

看起来您在 MailSenderConfiguration 中的属性源配置覆盖了 AppConfig 中的一个。

You can remove PropertyPlaceholderConfigurer bean from MailSenderConfiguration, and in AppConfig, set additional location for "mail.properties" (use setLocations() method instead of setLocation()):

您可以从 MailSenderConfiguration 中删除 PropertyPlaceholderConfigurer bean，并在 AppConfig 中为“mail.properties”设置附加位置（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;
}

回答by Plog

You should make sure the PropertyPlaceholderConfigurerbean is loaded before trying to evaluate properties by making the bean static. Spring instantiates static beans before other beans definitions.

PropertyPlaceholderConfigurer在尝试通过使 bean 静态化来评估属性之前，您应该确保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;
}