Java spring引导属性注入在自定义@Configuration类中不起作用

我想创建一个DatabaseConfig类来设置与数据库相关的内容（EntityManager、DataSource、TransactionManager），并获取我在

字符串
字段上使用的属性
@Value（${property.name}”）

像

问题是，所有这些字符串都是NULL，而不是我的属性文件的值

如果我将代码放入我的
应用程序
类（具有
main
且在
SpringApplication.run（Application.class，args）；
中引用的类），则值注入工作

简而言之，@Value在我的应用程序类中起作用，但在我的自定义@Configuration类中不起作用：(

可能有什么问题？或者是否需要更多信息

更新：更多代码

方式1，my Application.java中的DB Config和@Value在使用和不使用PropertySourcesPlaceholder配置器的情况下工作

import java.beans.PropertyVetoException;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;

import com.mchange.v2.c3p0.ComboPooledDataSource;

@Configuration
@ComponentScan
@EnableJpaRepositories
@EnableAutoConfiguration(exclude = HibernateJpaAutoConfiguration.class)
public class Application {
    public static void main(String[] args) throws Throwable {
        SpringApplication.run(Application.class, args);
    }

    // @Bean
    // public static PropertySourcesPlaceholderConfigurer properties() {
    // PropertySourcesPlaceholderConfigurer pspc = new PropertySourcesPlaceholderConfigurer();
    // pspc.setLocations(new Resource[] { new ClassPathResource("application.properties") });
    // return pspc;
    // }

    /*****************************/
    @Value("${hibernate.connection.username}")
    private String hibernateConnectionUsername;

    @Value("${hibernate.connection.password}")
    private String hibernateConnectionPassword;

    @Value("${hibernate.connection.driver_class}")
    private String hibernateConnectionDriverClass;

    @Value("${hibernate.connection.url}")
    private String hibernateConnectionUrl;

    @Value("${hibernate.dialect}")
    private String hibernateDialect;
    @Value("${hibernate.showSql}")
    private String hibernateShowSql;
    @Value("${hibernate.generateDdl}")
    private String hibernateGenerateDdl;

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setDatabasePlatform(hibernateDialect);
        boolean generateDdl = Boolean.parseBoolean(hibernateGenerateDdl);
        boolean showSql = Boolean.parseBoolean(hibernateShowSql);
        vendorAdapter.setGenerateDdl(generateDdl);
        vendorAdapter.setShowSql(showSql);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setDataSource(dataSource());
        factory.setPackagesToScan("xxx");

        return factory;
    }

    @Bean
    public DataSource dataSource() {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(hibernateConnectionUsername);
        dataSource.setPassword(hibernateConnectionPassword);
        try {
            dataSource.setDriverClass(hibernateConnectionDriverClass);
        } catch (PropertyVetoException e) {
            throw new IllegalArgumentException("Wrong driver class");
        }

        dataSource.setJdbcUrl(hibernateConnectionUrl);
        return dataSource;
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

方式2（我想要的），DB Stuff在它自己的文件（DatabaseConfing.java）中不起作用，因为我在哪里有
属性sourcespocholderconfigurer
（应用程序或DatabaseConfig），因为它总是在DatabaseConfig中的@Beans之后调用：(

成功了。
将以下
应用程序属性添加到
src/main/resources
（从而删除
DatabaseConfig
类）而不是
DatabaseConfig

#数据源配置
spring.datasource.driverClassName=
spring.datasource.url=
spring.datasource.username=
spring.datasource.password=
#JPA/HIbernate
spring.jpa.database-platform=
spring.jpa.generate-ddl=
spring.jpa.show-sql=

将替换为实际值，spring boot将处理此问题

提示：删除C3P0依赖项，因为Spring将为您（默认）提供tomcat连接池（该连接池更新且维护更活跃，尽管该名称在没有tomcat的情况下/在tomcat之外完全可用）。
不完全是重复的，但我希望接受的解决方案适用于您：查看您的容器文件（应用程序的上下文），
@Value
只是被处理成某种容器范围，您必须将
添加到上下文文件中我已经尝试使用PropertySourcesPlaceholderConfigurer，但占位符是在数据库内容的my Bean之后执行的。不管代码的位置如何（db或appliction类）请发布配置的其余部分，包括
属性资源占位符Configuere
。我刚刚添加了更多的代码。这是hibernate jpa自动配置程序的属性吗？
spring.jpa
属性是，其他属性是基本的spring jdbc属性（这些属性也可以在普通jdbc环境中工作）很好，它可以工作，但似乎spring配置了另一种命名策略。虽然我的旧表Camelcase喜欢我的enities，但它们现在是小写的，并且“HelloWorldEntity”->“hello\u world\u entity”bit我想我不太在乎，因为这个项目非常新，我认为没有理由强制使用其他命名策略默认情况下使用
ImprovedNamingStrategy
，但是通过添加一个属性
spring.jpa.hibernate.naming strategy
o可以覆盖的
应用程序.properties
。非常感谢，是这些吗属性（以及用于spring引导自动配置的其他属性）有文档记录的地方？您在哪里添加了此代码？我创建的CacheConfig文件也有相同的问题。我在应用程序classI上添加了此代码，但遇到了相同的问题，从组件中排除了配置。似乎可以解决某些配置文件中未注入@value的问题
import java.beans.PropertyVetoException;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;

import com.mchange.v2.c3p0.ComboPooledDataSource;

@Configuration
@ComponentScan
@EnableJpaRepositories
@EnableAutoConfiguration(exclude = HibernateJpaAutoConfiguration.class)
public class Application {
    public static void main(String[] args) throws Throwable {
        SpringApplication.run(Application.class, args);
    }

    // @Bean
    // public static PropertySourcesPlaceholderConfigurer properties() {
    // PropertySourcesPlaceholderConfigurer pspc = new PropertySourcesPlaceholderConfigurer();
    // pspc.setLocations(new Resource[] { new ClassPathResource("application.properties") });
    // return pspc;
    // }

    /*****************************/
    @Value("${hibernate.connection.username}")
    private String hibernateConnectionUsername;

    @Value("${hibernate.connection.password}")
    private String hibernateConnectionPassword;

    @Value("${hibernate.connection.driver_class}")
    private String hibernateConnectionDriverClass;

    @Value("${hibernate.connection.url}")
    private String hibernateConnectionUrl;

    @Value("${hibernate.dialect}")
    private String hibernateDialect;
    @Value("${hibernate.showSql}")
    private String hibernateShowSql;
    @Value("${hibernate.generateDdl}")
    private String hibernateGenerateDdl;

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setDatabasePlatform(hibernateDialect);
        boolean generateDdl = Boolean.parseBoolean(hibernateGenerateDdl);
        boolean showSql = Boolean.parseBoolean(hibernateShowSql);
        vendorAdapter.setGenerateDdl(generateDdl);
        vendorAdapter.setShowSql(showSql);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setDataSource(dataSource());
        factory.setPackagesToScan("xxx");

        return factory;
    }

    @Bean
    public DataSource dataSource() {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(hibernateConnectionUsername);
        dataSource.setPassword(hibernateConnectionPassword);
        try {
            dataSource.setDriverClass(hibernateConnectionDriverClass);
        } catch (PropertyVetoException e) {
            throw new IllegalArgumentException("Wrong driver class");
        }

        dataSource.setJdbcUrl(hibernateConnectionUrl);
        return dataSource;
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        return new JpaTransactionManager(entityManagerFactory);
    }
}

import java.beans.PropertyVetoException;
import java.util.ArrayList;
import java.util.List;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.type.filter.AnnotationTypeFilter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;

import com.mchange.v2.c3p0.ComboPooledDataSource;


@Configuration
public class DatabaseConfig {
    @Value("${hibernate.connection.username}")
    private String hibernateConnectionUsername;
    @Value("${hibernate.connection.password}")
    private String hibernateConnectionPassword;
    @Value("${hibernate.connection.driver_class}")
    private String hibernateConnectionDriverClass;
    @Value("${hibernate.connection.url}")
    private String hibernateConnectionUrl;
    @Value("${hibernate.dialect")
    private String hibernateDialect;
    @Value("${hibernate.showSql}")
    private String hibernateShowSql;
    @Value("${hibernate.generateDdl}")
    private String hibernateGenerateDdl;

        // @Bean
        // public static PropertySourcesPlaceholderConfigurer properties() {
        // PropertySourcesPlaceholderConfigurer pspc = new PropertySourcesPlaceholderConfigurer();
        // pspc.setLocations(new Resource[] { new ClassPathResource("application.properties") });
        // return pspc;
        // }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setDatabasePlatform(hibernateDialect);
        boolean generateDdl = Boolean.parseBoolean(hibernateGenerateDdl);
        boolean showSql = Boolean.parseBoolean(hibernateShowSql);
        vendorAdapter.setGenerateDdl(generateDdl);
        vendorAdapter.setShowSql(showSql);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setDataSource(dataSource());
        factory.setPackagesToScan("xxx");

        return factory;
    }

    @Bean
    public DataSource dataSource() {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(hibernateConnectionUsername);
        dataSource.setPassword(hibernateConnectionPassword);
        try {
            dataSource.setDriverClass(hibernateConnectionDriverClass);
        } catch (PropertyVetoException e) {
            throw new IllegalArgumentException("Wrong driver class");
        }
        System.err.println(hibernateConnectionUrl);
        dataSource.setJdbcUrl(hibernateConnectionUrl);
        return dataSource;
    }
}

@Import({ CacheConfig.class, DatabaseConfig.class })
@ComponentScan(excludeFilters = @Filter(Configuration.class))

#DataSource configuration
spring.datasource.driverClassName=<hibernateConnectionDriverClass>
spring.datasource.url=<hibernateConnectionUrl>
spring.datasource.username=<hibernateConnectionUsername>
spring.datasource.password=<hibernateConnectionPassword>

#JPA/HIbernate
spring.jpa.database-platform=<dialect-class>
spring.jpa.generate-ddl=<hibernateGenerateDdl>
spring.jpa.show-sql=<hibernateShowSql>