如何解决期望至少有1个符合自动装配候选条件的bean依赖注释
public class MyWebInitializer implements WebApplicationInitializer {
public static Logger logger = Logger.getLogger(MyWebInitializer.class);
@Override
public void onStartup(ServletContext servletContext) throws servletexception {
logger.info("initializing web context");
AnnotationConfigWebApplicationContext annotationConfigWebApplicationContext = new AnnotationConfigWebApplicationContext();
annotationConfigWebApplicationContext.register(FrontController.class);
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher",new dispatcherServlet(annotationConfigWebApplicationContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
logger.info("On start up method complete");
}
}
前端控制器设置：
@Configuration
@EnableWebMvc
@ComponentScan("com.ishwor.crm.controller,com.ishwor.crm.entity,com.ishwor.crm.DAO")
@PropertySource("classpath:hibenrate.properties")
@EnableTransactionManagement
public class FrontController implements WebMvcConfigurer {
public static Logger logger = Logger.getLogger(FrontController.class);
@Autowired
Environment environment;
@Bean
InternalResourceViewResolver internalResourceViewResolver() {
logger.info("inside view resolver function ");
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/views/");
resolver.setSuffix(".jsp");
resolver.setViewClass(JstlView.class);
logger.info("View Resolving complete ");
return resolver;
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
logger.info("Inside static resource handler");
// for css and js
registry.addResourceHandler("/resources/**").addResourceLocations("/WEB-INF/resources/")
.setCacheControl(CacheControl.maxAge(2,TimeUnit.HOURS).cachePublic());
logger.info("static resource handling complete");
}
// hibernate configuration
@Bean(name = "sessionFactory")
public LocalSessionfactorybean sessionBean() {
logger.info("Creating sesion bean");
LocalSessionfactorybean bean = new LocalSessionfactorybean();
bean.setDataSource(dataSource());
bean.setPackagesToScan(
new String[] { "com.ishwor.crm.entity","com.ishwor.crm.DAO","com.ishwor.crm.DAOImpl" });
bean.setHibernateProperties(hibernateProperties());
logger.info("Creating sesion bean=== successfull!!!");
return bean;
}
@Bean
public DataSource dataSource() {
logger.info("Datasource method invoked");
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(environment.getrequiredProperty("jdbc.driverClassName"));
dataSource.setUsername(environment.getrequiredProperty("jdbc.username"));
dataSource.setPassword(environment.getrequiredProperty("jdbc.password"));
dataSource.setUrl(environment.getrequiredProperty("jdbc.url"));
logger.info("DataSource Invoke complete");
return dataSource;
}
private Properties hibernateProperties() {
Properties properties = new Properties();
logger.info("setting properties for hibernated");
properties.put("hibernate.dialect",environment.getrequiredProperty("hibernate.dialect"));
properties.put("hibernate.show_sql",environment.getrequiredProperty("hibernate.show_sql"));
properties.put("hibernate.format_sql",environment.getrequiredProperty("hibernate.format_sql"));
properties.put("hibernate.hbm2ddl.auto",environment.getrequiredProperty("hibernate.hbm2ddl.auto"));
logger.info("setting properties completed");
return properties;
}
@Bean
public HibernateTransactionManager getTransactionManager() {
HibernateTransactionManager transactionManager = new HibernateTransactionManager();
transactionManager.setSessionFactory(sessionBean().getobject());
return transactionManager;
}
}
实体设置：
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "customer")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private long id;
@Column(name = "first_name")
private String firstName;
@Column(name = "last_name")
private String lastName;
@Column(name = "email")
private String email;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Customer() {
}
public Customer(String firstName,String lastName,String email) {
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
@Override
public String toString() {
return "Customer [id=" + id + ",firstName=" + firstName + ",lastName=" + lastName + ",email=" + email + "]";
}
}
DAO设置：
package com.ishwor.crm.DAO;
import java.util.List;
import com.ishwor.crm.entity.Customer;
public interface CustomerDAO {
public List<Customer> getCustomer();
}
DAOImpl设置
package com.ishwor.crm.DAOImpl;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.query.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import com.ishwor.crm.DAO.CustomerDAO;
import com.ishwor.crm.entity.Customer;
@Repository
public class CustomerDAOImpl implements CustomerDAO {
@Autowired
@Qualifier("sessionFactory")
private SessionFactory sessionFactory;
public CustomerDAOImpl() {
}
@Override
@Transactional
public List<Customer> getCustomer() {
// get current hibernate Session
Session currenSession = sessionFactory.getCurrentSession();
// create Query
Query<Customer> myQuery = currenSession.createquery("from customer",Customer.class);
// execute query and get result
return myQuery.getResultList();
}
}
但是使用此DAO作为自动连线显示错误，我有以下customerController设置：
package com.ishwor.crm.controller;
import java.util.List;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import com.ishwor.crm.DAO.CustomerDAO;
import com.ishwor.crm.entity.Customer;
@Controller()
@RequestMapping("/customer")
public class CustomerController {
public static Logger logger = Logger.getLogger(CustomerController.class);
// Autowired customerDAO
@Autowired
private CustomerDAO customerDAO;
@RequestMapping("/list")
public String customerHome(Model model) {
logger.info("customer index metho browsed");
List<Customer> customer = customerDAO.getCustomer();
model.addAttribute("customer",customer);
return "/customer/index";
}
}
注意，无需自动装配控制器类代码即可正常工作。 我是否应该使用@service注释以及另外一个其他类和接口来进行此项工作。
解决方法
组件扫描失败。
在com.ishwor.crm.DAOImpl中的代码中添加@ComponentScan包：
@ComponentScan("com.ishwor.crm.controller,com.ishwor.crm.entity,com.ishwor.crm.DAO,com.ishwor.crm.DAOImpl")
在CustomerDAOImpl中用CustomerDAO替换CustomerController。它将起作用。
@Autowired
private CustomerDAO customerDAO;
我认为Spring默认按名称自动装配。您要么需要将Controller的局部变量重命名为“ ... Impl”，要么需要覆盖Impl类的默认名称。
,看起来spring不会扫描customerDaoImpl进行注释处理。检查您的配置，@Autowired将根据bean类型自动解析。因此，自动装配是正确的，它不是扫描@Repository注释，而是不创建其bean
,要扫描多个软件包，请使用如下所示的String数组：
@ComponentScan({"com.ishwor.crm.controller","com.ishwor.crm.entity","com.ishwor.crm.DAO"})
是的，每当您需要缓存数据时，应该尝试使用@Service类，以便更好地在服务类中最后缓存数据，而不是列表@Repository @Service @Controller如果您正确使用它们，则这3个是专用的@Component，也称为3层架构。如果您的项目规模很大，那么将对您有很大帮助。业务逻辑应该在服务类中。
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