Question

这是我的错误，我将要连接多个mysql DB＆＃39。对于一个DB，它完美地工作。然后我尝试了2个DB，但我收到了错误。请帮我解决这个问题。似乎我对多个DB的更改是错误的： - \

错误

    ec 10, 2015 10:23:06 PM org.springframework.web.context.support.AnnotationConfigWebApplicationContext loadBeanDefinitions
INFO: Found 4 annotated classes in package [net.codejava.spring]
Dec 10, 2015 10:23:07 PM org.springframework.web.servlet.DispatcherServlet initServletBean
SEVERE: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private net.codejava.spring.dao.ContactDAO net.codejava.spring.controller.HomeController.contactDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private net.codejava.spring.dao.ContactDAO net.codejava.spring.controller.HomeController.contactDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1103)

Dec 10, 2015 10:23:07 PM org.apache.catalina.core.ApplicationContext log
SEVERE: StandardWrapper.Throwable
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private net.codejava.spring.dao.ContactDAO net.codejava.spring.controller.HomeController.contactDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private net.codejava.spring.dao.ContactDAO net.codejava.spring.controller.HomeController.contactDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1103)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:963)

Dec 10, 2015 10:23:07 PM org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /SpringMvcJdbcTemplate threw load() exception
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [net.codejava.spring.dao.ContactDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1103)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:963)

这是我的控制器类

@Controller 公共课HomeController {

@Autowired
private ContactDAO contactDAO;

@Autowired
private ContactDAO2 contactDAO2;

@RequestMapping(value = "/")
public ModelAndView listContact(ModelAndView model) throws IOException {
    List<Contact> listContact = contactDAO.list();
    model.addObject("listContact", listContact);
    model.setViewName("home");

    return model;
}

这是我的DAO Class＃01

public interface ContactDAO {

    public void saveOrUpdate(Contact contact);

这是我的DAO Class＃02

public interface ContactDAO2 {

    public void saveOrUpdate(Contact contact);

这是我的DAOImpl类

public class ContactDAO2Impl implements ContactDAO2 {

    @Autowired 
    @Qualifier("jdbcItems") 
    private JdbcTemplate jdbcTemplate;

    public ContactDAO2Impl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Override
    public void saveOrUpdate(Contact contact) {
        if (contact.getId() > 0) {
            // update
            String sql = "UPDATE contact SET name=?, email=?, address=?, "
                        + "telephone=? WHERE contact_id=?";
            jdbcTemplate.update(sql, contact.getName(), contact.getEmail(),
                    contact.getAddress(), contact.getTelephone(), contact.getId());
        }

这是我的另一个DAOImpl类

public class ContactDAOImpl implements ContactDAO {

    @Autowired 
    @Qualifier("jdbcUsers") 
    private JdbcTemplate jdbcTemplate;

    public ContactDAOImpl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Override
    public void saveOrUpdate(Contact contact) {
        if (contact.getId() > 0) {
            // update
            String sql = "UPDATE contact SET name=?, email=?, address=?, "
                        + "telephone=? WHERE contact_id=?";
            jdbcTemplate.update(sql, contact.getName(), contact.getEmail(),
                    contact.getAddress(), contact.getTelephone(), contact.getId());
        }

下面显示了我的配置类的配置＃01

    @Configuration
    @ComponentScan(basePackages="net.codejava.spring")
    @EnableWebMvc
    public class MvcConfiguration extends WebMvcConfigurerAdapter{

        @Bean
        public ViewResolver getViewResolver(){
            InternalResourceViewResolver resolver = new InternalResourceViewResolver();
            resolver.setPrefix("/WEB-INF/views/");
            resolver.setSuffix(".jsp");
            return resolver;
        }

        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
        }


    }

配置＃02

@Configuration
public class DatabaseItemsConfig {

    @Bean(name = "jdbcItems")
    public JdbcTemplate jdbcTemplate(DataSource dsItems) {
        return new JdbcTemplate(dsItems);
    }

    @Bean(name = "dsItems")
    public DataSource getDataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUsername("root");
        dataSource.setPassword("321");
        return dataSource;
    }

}

配置＃03

    @Configuration
public class DatabaseUsersConfig {


    @Bean(name = "jdbcUsers") 
    public JdbcTemplate jdbcTemplate(DataSource dsUsers) {
        return new JdbcTemplate(dsUsers);
    }

    @Bean(name = "dsUsers") 
    public DataSource getDataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/test2");
        dataSource.setUsername("root");
        dataSource.setPassword("321");
        return dataSource;
    }

}

修改

使用源代码上传的整个项目

Click here to see & get my whole project code

Answer 1

你在接线方面遇到很多问题......要解决这个问题：

删除（来自ContactDAOImpl）

 @Autowired 
 @Qualifier("jdbcUsers")

和（来自ContactDAO2Impl）

 @Autowired 
 @Qualifier("jdbcItems")

和

 @Bean(name = "jdbcItems")
 public JdbcTemplate jdbcTemplate(DataSource dsItems) {
    return new JdbcTemplate(dsItems);
 }

和

 @Bean(name = "jdbcUsers") 
 public JdbcTemplate jdbcTemplate(DataSource dsUsers) {
    return new JdbcTemplate(dsUsers);
 }

然后替换

 public ContactDAO2Impl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
 }

通过

 public ContactDAO2Impl(@Qualifier("dsItems") DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
 }

并替换

 public ContactDAOImpl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
 }

通过

 public ContactDAOImpl(@Qualifier("dsUsers") DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
 }

当我尝试连接到多个DB时，为什么会出现SpringJDBCTemplate问题？

1 个答案: