Question

我正在开发 Spring MVC + Security + MySQL 示例。我从 http://www.mkyong.com/spring-security/spring-security-form-login-using-database/ 中获取了参考资料。在这个项目中，我进行了一些自定义，在此我创建了"database.properties"文件并尝试将其加载到AppConfig.java中。当我部署这个项目时，我看到下面的错误。请帮忙！

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration.setFilterChainProxySecurityConfigurer(org.springframework.security.config.annotation.ObjectPostProcessor,java.util.List) throws java.lang.Exception; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.mkyong.config.SecurityConfig': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: javax.sql.DataSource com.mkyong.config.SecurityConfig.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class com.mkyong.config.AppConfig: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.jdbc.datasource.DriverManagerDataSource com.mkyong.config.AppConfig.dataSource()] threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [${mysql.jdbc.driver}]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1146)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:296)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:293)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:410)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4840)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5303)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration.setFilterChainProxySecurityConfigurer(org.springframework.security.config.annotation.ObjectPostProcessor,java.util.List) throws java.lang.Exception; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.mkyong.config.SecurityConfig': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: javax.sql.DataSource com.mkyong.config.SecurityConfig.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class com.mkyong.config.AppConfig: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.jdbc.datasource.DriverManagerDataSource com.mkyong.config.AppConfig.dataSource()] threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [${mysql.jdbc.driver}]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:604)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:286)
    ... 22 more
Caused by: org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.mkyong.config.SecurityConfig': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: javax.sql.DataSource com.mkyong.config.SecurityConfig.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class com.mkyong.config.AppConfig: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.jdbc.datasource.DriverManagerDataSource com.mkyong.config.AppConfig.dataSource()] threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [${mysql.jdbc.driver}]
    at org.springframework.context.expression.StandardBeanExpressionResolver.evaluate(StandardBeanExpressionResolver.java:142)
    at org.springframework.beans.factory.support.AbstractBeanFactory.evaluateBeanDefinitionString(AbstractBeanFactory.java:1318)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:782)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:561)
    ... 24 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.mkyong.config.SecurityConfig': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: javax.sql.DataSource com.mkyong.config.SecurityConfig.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class com.mkyong.config.AppConfig: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.jdbc.datasource.DriverManagerDataSource com.mkyong.config.AppConfig.dataSource()] threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [${mysql.jdbc.driver}]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)

我的更新代码，其他文件不变。的 database.properties

mysql.jdbc.driver=com.mysql.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/test
mysql.username=root
mysql.password=root

AppConfig.java

@EnableWebMvc
@Configuration
@ComponentScan({ "com.mkyong.web.*" })
@Import({ SecurityConfig.class })
@PropertySource({"classpath:database.properties"})
public class AppConfig {

    @Value("${mysql.jdbc.driver}")
    private String driverClass;

    @Value("${mysql.url}")
    private String url;

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

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


    @Bean(name = "dataSource")
    public DriverManagerDataSource dataSource() {
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
        /*driverManagerDataSource.setDriverClassName("com.mysql.jdbc.Driver");
        driverManagerDataSource.setUrl("jdbc:mysql://localhost:3306/test");
        driverManagerDataSource.setUsername("root");
        driverManagerDataSource.setPassword("root");*/

        driverManagerDataSource.setDriverClassName(driverClass);
        driverManagerDataSource.setUrl(url);
        driverManagerDataSource.setUsername(username);
        driverManagerDataSource.setPassword(password);

        return driverManagerDataSource;
    }

    @Bean
    public InternalResourceViewResolver viewResolver() {
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setViewClass(JstlView.class);
        viewResolver.setPrefix("/WEB-INF/pages/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }
}

Answer 1

java.lang.IllegalStateException：无法加载JDBC驱动程序类 [$ {mysql.jdbc.driver}]

实际上，占位符${mysql.jdbc.driver}未得到解决。

您可以使用以下占位符配置器 bean来解析此值占位符。

@Bean
public static PropertySourcesPlaceholderConfigurer propertyPlaceholderConfigurer() {
    return new PropertySourcesPlaceholderConfigurer();
}

PropertySourcesPlaceholderConfigurer

解决$ {...}的PlaceholderConfigurerSupport的专业化   bean定义属性值和@Value中的占位符   针对当前Spring环境及其集合的注释   PropertySources。

Answer 2

初始化配置时，您可以使用spring生成的环境变量从属性文件中获取值。我认为，如果您使用spring，这是从属性文件中获取值的最佳和最明确的方法。

直接从环境变量

获取值

  //other annotation
  @PropertySource(value = { "properties file path" })
  public class AppConfig{

    @Autowired
    private Environment environment;      

  @Bean
  public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName(environment.getRequiredProperty("jdbc.driverClassName"));
    dataSource.setUrl(environment.getRequiredProperty("jdbc.url"));
    dataSource.setUsername(environment.getRequiredProperty("jdbc.username"));
    dataSource.setPassword(environment.getRequiredProperty("jdbc.password"));
    return dataSource;
}

创建名为'org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration'的bean时出错：

2 个答案: