不滿足的依賴例外：創建帶有名稱的bean時出錯-有解無憂

我是 Spring 的新手，我剛剛啟動了一個 Spring MVC CRUD 程式，但是在嘗試了很多方法之后，我一次又一次地面臨同樣的錯誤。

這是列印 HTTP 狀態 500 – 內部服務器錯誤的第一個例外。

HTTP 狀態 500 – 內部服務器錯誤

javax.servlet.ServletException: Servlet [dispatcher] 的 Servlet.init() 拋出例外 org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve. java:92) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) org.apache.coyote.http11.Http11Processor。服務（Http11Processor.java:382）org.apache.coyote.AbstractProcessorLight.process（AbstractProcessorLight.java:65）org.apache.coyote.AbstractProtocol$ConnectionHandler.process（AbstractProtocol.java:895）org.apache.tomcat.util。 net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1732) org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) org.apache.tomcat.util.threads。ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread. java:61) java.lang.Thread.run(未知來源)

不滿足的依賴例外

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentDao' defined in file [C:\Users\MOHIT SINGH\Documents\workspace-spring-tool-suite-4-4.6.2.RELEASE\.metadata\.plugins\org.eclipse.wst.server.core\tmp2\wtpwebapps\STUDENT-SPRING-MVC\WEB-INF\classes\com\spring\student\dao\StudentDaoImpl.class]: Unsatisfied dependency expressed through constructor parameter 0: No qualifying bean of type [java.lang.Class] found for dependency [java.lang.Class<com.spring.student.model.Student>]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [java.lang.Class] found for dependency [java.lang.Class<com.spring.student.model.Student>]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)
    org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:775)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:540)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1732)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
    org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)

NoSuchBeanDefinitionException

org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [java.lang.Class] found for dependency [java.lang.Class<com.spring.student.model.Student>]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
    org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1398)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1051)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1018)
    org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:834)
    org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741)
    org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:775)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:540)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1732)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
    org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)

**Code**

Here is My Code


    <project xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.java.spring</groupId>
        <artifactId>STUDENT-SPRING-MVC</artifactId>
        <packaging>war</packaging>
        <version>0.0.1-SNAPSHOT</version>
        <name>STUDENT-SPRING-MVC Maven Webapp</name>
        <url>http://maven.apache.org</url>
        <properties>
            <springframework.version>4.3.0.RELEASE</springframework.version>
            <hibernate.version>4.3.6.Final</hibernate.version>
            <mysql.version>5.1.31</mysql.version>
            <joda-time.version>2.3</joda-time.version>
        </properties>
        <dependencies>
            <!-- Spring -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
                <version>${springframework.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-web</artifactId>
                <version>${springframework.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>${springframework.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-tx</artifactId>
                <version>${springframework.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-orm</artifactId>
                <version>${springframework.version}</version>
            </dependency>
    
            <!-- Hibernate -->
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
                <version>${hibernate.version}</version>
            </dependency>
    
            <!-- jsr303 validation -->
            <dependency>
                <groupId>javax.validation</groupId>
                <artifactId>validation-api</artifactId>
                <version>1.1.0.Final</version>
            </dependency>
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-validator</artifactId>
                <version>5.1.3.Final</version>
            </dependency>
    
            <!-- MySQL -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.26</version>
            </dependency>
    
            <!-- Joda-Time -->
            <dependency>
                <groupId>joda-time</groupId>
                <artifactId>joda-time</artifactId>
                <version>${joda-time.version}</version>
            </dependency>
    
            <!-- To map JodaTime with database type -->
            <dependency>
                <groupId>org.jadira.usertype</groupId>
                <artifactId>usertype.core</artifactId>
                <version>3.0.0.CR1</version>
            </dependency>
    
            <!-- Servlet JSP JSTL -->
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
            </dependency>
    
            <dependency>
                <groupId>javax.servlet.jsp</groupId>
                <artifactId>javax.servlet.jsp-api</artifactId>
                <version>2.3.1</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
    
    
            <!-- Testing dependencies -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-test</artifactId>
                <version>${springframework.version}</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.testng</groupId>
                <artifactId>testng</artifactId>
                <version>7.5</version>
                <scope>test</scope>
            </dependency>
        </dependencies>
        <build>
            <finalName>STUDENT-SPRING-MVC</finalName>
            <plugins>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.5.1</version>
                    <configuration>
                        <source>1.7</source>
                        <target>1.7</target>
                    </configuration>
                </plugin>
                <plugin>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>2.6</version>
                    <configuration>
                        <failOnMissingWebXml>false</failOnMissingWebXml>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>

配置

package com.spring.student.configuration;

import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc
@ComponentScan("com.spring.student")
public class MyWebConfig {

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

        return viewResolver;
    }

    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
        messageSource.setBasename("messages");
        return messageSource;
    }

}

Servlet 初始化器

package com.spring.student.configuration;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class ServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {

        return null;
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {

        return new Class[] {MyWebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {

        return new String[] { "/" };
    }

}

**HibernateConfiguration**

    package com.spring.student.configuration;
    
    import java.util.Properties;
    
    import javax.sql.DataSource;
    
    import org.hibernate.SessionFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.core.env.Environment;
    import org.springframework.jdbc.datasource.DriverManagerDataSource;
    import org.springframework.orm.hibernate4.HibernateTransactionManager;
    import org.springframework.orm.hibernate4.LocalSessionFactoryBean;
    import org.springframework.transaction.annotation.EnableTransactionManagement;
    
    @Configuration
    @EnableTransactionManagement
    @ComponentScan({ "com.spring.student.configuration" })
    @PropertySource(value = { "classpath:application.properties" })
    public class MyHibernateConfig {
    
        @Autowired
        private Environment environment;
    
        @Bean
        public LocalSessionFactoryBean sessionFactory() {
            LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
            sessionFactory.setDataSource(dataSource());
            sessionFactory.setPackagesToScan(new String[] { "com.spring.student.model" });
            sessionFactory.setHibernateProperties(hibernateProperties());
            return sessionFactory;
        }
    
        @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;
        }
    
        public Properties hibernateProperties() {
            Properties properties = new Properties();
            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"));
            return properties;
        }
    
        @Bean
        @Autowired
        public HibernateTransactionManager transactionManager(SessionFactory s) {
            HibernateTransactionManager txManager = new HibernateTransactionManager();
            txManager.setSessionFactory(s);
            return txManager;
        }
    
    }

**Dao**

    package com.spring.student.dao;
    
    import java.io.Serializable;
    
    import org.hibernate.Criteria;
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import java.lang.reflect.ParameterizedType;
    import org.springframework.beans.factory.annotation.Autowired;
    
    public abstract class AbstStudentDao<PK extends Serializable, T> {
    
        private final Class<T> persistentClass;
    
        @SuppressWarnings("unchecked")
        public AbstStudentDao(Class<T> persistentClass) {
            super();
            this.persistentClass = (Class) ((ParameterizedType) this.getClass().getGenericSuperclass())
                    .getActualTypeArguments()[1];
        }
    
        @Autowired
        private SessionFactory sessionFactory;
    
        protected Session getSession() {
            return sessionFactory.getCurrentSession();
        }
    
        @SuppressWarnings("unchecked")
        public T getByKey(PK key) {
            return (T) getSession().get(persistentClass, key);
        }
    
        public void persist(T entity) {
            getSession().persist(entity);
        }
    
        public void saveOrUpdate(T entity) {
            getSession().saveOrUpdate(entity);
        }
    
        public void delete(T entity) {
            getSession().delete(entity);
        }
    
        protected Criteria createEntityCriteria() {
            return getSession().createCriteria(persistentClass);
        }
    
    }


**DaoImpl**

    package com.spring.student.dao;
    
    import java.util.List;
    
    import org.hibernate.Criteria;
    import org.hibernate.Query;
    import org.hibernate.criterion.Restrictions;
    import org.springframework.stereotype.Repository;
    
    import com.spring.student.model.Student;
    
    @Repository("studentDao")
    public class StudentDaoImpl extends AbstStudentDao<Integer, Student> implements StudentDao {
    
        public StudentDaoImpl(Class<Student> persistentClass) {
            super(persistentClass);
    
        }
        
        public void saveOrUpdate(Student student) {
            super.saveOrUpdate(student);
        }
    
        @Override
        public Student findById(int id) {
    
            return getByKey(id);
        }
    
        @Override
        public void saveStudent(Student student) {
            persist(student);
    
        }
    
        @Override
        public void deleteStudentByCode(String code) {
            Query query = getSession().createQuery("delete from student where code = :code");
            query.setParameter("code", code);
            query.executeUpdate();
    
        }
    
        @SuppressWarnings("unchecked")
        @Override
        public List<Student> findAllStudents() {
            Criteria criteria = createEntityCriteria();
            return (List<Student>) criteria.list();
    
        }
    
        @Override
        public Student findStudentByCode(String code) {
    
            Criteria criteria = createEntityCriteria();
            criteria.add(Restrictions.eq("code", code));
            return (Student) criteria.uniqueResult();
        }
    
    }



**ServiceImple**


    package com.spring.student.service;
    
    import java.util.List;
    
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    
    import com.spring.student.dao.StudentDao;
    import com.spring.student.model.Student;
    
    @Service("studentService")
    @Transactional
    public class StudentServiceImpl implements StudentService {
    
        private StudentDao studentDao;
    
        @Override
        public Student findById(int Id) {
    
            return studentDao.findById(Id);
        }
    
        @Override
        public void saveStudent(Student student) {
    
            studentDao.saveStudent(student);
    
        }
    
        @Override
        public void updateStudent(Student student) {
    
            Student entity = studentDao.findById(student.getId());
            if (entity != null) {
                entity.setName(student.getName());
                entity.setEnteringDate(student.getEnteringDate());
                entity.setNationality(student.getNationality());
                entity.setCode(student.getCode());
            }
    
        }
    
        @Override
        public List<Student> findAllStudent() {
    
            return studentDao.findAllStudents();
        }
    
        @Override
        public Student findStudentByCode(String code) {
    
            return studentDao.findStudentByCode(code);
        }
    
        @Override
        public boolean isStudentCodeUnique(Integer id, String code) {
            Student student = findStudentByCode(code);
            return (student == null || ((id != null) && (student.getId() == id)));
        }
    
        @Override
        public void deleteStudentByCode(String code) {
            studentDao.deleteStudentByCode(code);
    
        }
    
    }




 

**Controller**

    package com.spring.student.controller;
    
    import java.util.Locale;
    import javax.validation.Valid;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.MessageSource;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.ModelMap;
    import org.springframework.validation.BindingResult;
    import org.springframework.validation.FieldError;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import com.spring.student.model.Student;
    import com.spring.student.service.StudentService;
    
    @Controller
    @RequestMapping("/")
    public class MyController {
    
        @Autowired
        StudentService service;
    
        @Autowired
        MessageSource messageSource;
    
        @RequestMapping(value = { "/new" }, method = RequestMethod.GET)
        public String studentList(ModelMap model) {
    
            Student student = new Student();
            model.addAttribute("student", student);
            model.addAttribute("edit", false);
            return "registration";
        }
    
        @RequestMapping(value = { "/new" }, method = RequestMethod.POST)
        public String saveStudent(@Valid Student student, BindingResult result, ModelMap model) {
            if (result.hasErrors()) {
                return "registration";
            }
            if (!service.isStudentCodeUnique(student.getId(), student.getCode())) {
                FieldError codeError = new FieldError("student", "code", messageSource.getMessage("non.unique.code",
                        new String[] { student.getCode() }, Locale.getDefault()));
                result.addError(codeError);
                return "registration";
            }
            service.saveStudent(student);
            model.addAttribute("success", "student"   student.getName()   "Registration Successfull");
            return "success";
        }
    
        @RequestMapping(value = { "/edit-{code}-student" }, method = RequestMethod.GET)
        public String editStudent(@PathVariable String code, ModelMap model) {
            Student student = service.findStudentByCode(code);
            model.addAttribute("student", student);
            model.addAttribute("edit", true);
            return "registration";
        }
    
        @RequestMapping(value = { "/edit-{code}-student" }, method = RequestMethod.POST)
        public String updateStudent(@Valid Student student, BindingResult result, ModelMap model,
                @PathVariable String code) {
            if (result.hasErrors()) {
                return "registration";
            }
    
            if (!service.isStudentCodeUnique(student.getId(), student.getCode())) {
                FieldError codeError = new FieldError("student", "code", messageSource.getMessage("non.unique.code",
                        new String[] { student.getCode() }, Locale.getDefault()));
                result.addError(codeError);
                return "registration";
            }
            service.saveStudent(student);
            model.addAttribute("success", "student"   student.getName()   "Update SuccessFully Completed");
            return "success";
        }
    
        @RequestMapping(value = { "/delete-{code}-student" }, method = RequestMethod.GET)
        public String deleteStudent(@PathVariable String code) {
            service.deleteStudentByCode(code);
            return "redirect:/list";
        }
    }

uj5u.com熱心網友回復：

您是否嘗試在 StudentDaoImpl 建構式中將 Class<Student> 設定為 Student？沒有Class<>就不允許嗎？

uj5u.com熱心網友回復：

StudentDaoImpl將類的建構式更改為

public StudentDaoImpl() {
            super(Student.class);
   }

并studentdao在StudentServiceImpl課堂上自動接線

希望它會起作用

轉載請註明出處，本文鏈接：https://www.uj5u.com/gongcheng/422348.html

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