Dao и JpaRepositories выбрасывают исключение NullPointerException при @Autowiring - PullRequest
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Dao и JpaRepositories выбрасывают исключение NullPointerException при @Autowiring

0 голосов
/ 26 мая 2020

Проблема: Автоматическое подключение компонентов SingerDaoImpl и JpaRepositoryImpl приводит к нулевому результату. Исключение не генерируется, но данные не возвращаются. Использование представления Thymeleaf для отображения данных

Используемые технологии: Spring, JpaRepository, Hibernate, Thymeleaf, H2 Embedded DB (скрипт находится в папке resources / SQL), Spring MVC, javax.validation.

Я использую localhost: 8080 / singers для перечисления певцов через тимелеаф, расположенный в resources / templates / listSingers. html. После вызова контроллера / singers количество извлеченных певцов регистрируется в консоли через регистратор

То, что я вычеркнул: - Нет @Component (или его специализаций) Класс объявляется с новым оператором - Все bean-компоненты с @Autowired аннотируются @Component, @Repository или @Service - Сеттеры уже настроены, - @Qualifier уже указывает на правильный bean-компонент - Встроенная база данных IS заполняется данными, расположенными в resources / SQL / test. sql, и добавляется через класс DBConfig. java с помощью метода EmbeddedDatabaseBuilder.addScript ("SQL / test. sql") - Все зависимости в версии файла gradle.build управляются gradle как последняя версия

Ссылка на страницу github: https://github.com/NikitaDyagilev/LearningSprinbMVC

примечание: я использую Amazon Corretto Java 11

DBConfig. java

package com.example.demo.Config;

@Configuration
@ComponentScan
@EnableJpaRepositories(basePackages = {"com.example.demo.JpaRepo"})
@PropertySource("classpath:application.properties")
public class DBconfig {

     @Value("${jdbc.driverClassName}")
     private String driverClassName;
     @Value("${jdbc.username}")
     private String username;
     @Value("${jdbc.password}")
     private String password;
     @Value("${jdbc.url}")
     private String url;

     private Logger logger = LoggerFactory.getLogger(DBconfig.class);

//   MySQL DataSource Connection
     @Bean
     public DataSource dataSourceR(){
          try{
               SimpleDriverDataSource db =
                       new SimpleDriverDataSource();
               Class<? extends Driver> driver =
                       (Class<? extends Driver>) Class.forName(driverClassName);
               db.setDriverClass(driver);
               db.setUsername(username);
               db.setPassword(password);
               db.setUrl(url);
               return db;
          } catch (Exception e){
               logger.error("Something Went wrong when trying to Create the MySQL DataSource bean");
               return null;
          }
     }

//   Embedded DataSource Connection
     @Bean
     public DataSource dataSourceE(){
          try{
               EmbeddedDatabaseBuilder db =
                       new EmbeddedDatabaseBuilder();
               db.setType(EmbeddedDatabaseType.H2);
               db.addScript("SQL/table.sql");
               db.addScript("SQL/test.sql");
               return db.build();
          } catch (Exception e ){
               logger.error("There was an error when trying to create Embeded DataSource: ", e);
               return null;
          }
     }

     @Bean
     public Properties hibernaProperties(){
          Properties prop = new Properties();
          prop.put("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
//          prop.put("hibernate.dialect", "org.hibernate.dialect.MySQL8Dialect");
          prop.put("hibernate.hbm2ddl.auto", "create-drop");
          prop.put("hibernate.format_sql", true);
          prop.put("hibernate.show_sql", true);
          prop.put("hibernate.max_fetch_depth", 3);
          prop.put("hibernate.jdbc.batch_size", 10);
          prop.put("hibernate.jdbc.fetch_size", 50);
          return prop;
     }

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

     @Bean
     public JpaVendorAdapter jpaVendorAdapter(){
          return new HibernateJpaVendorAdapter();
     }

     @Bean(name ="entityManagerFactory")
     public EntityManagerFactory entityManagerFactory(){
          LocalContainerEntityManagerFactoryBean emfb =
                  new LocalContainerEntityManagerFactoryBean();
          emfb.setDataSource(dataSourceE());
          emfb.setPackagesToScan("com.example.demo.Model");
          emfb.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
          emfb.setJpaProperties(hibernaProperties());
          emfb.setJpaVendorAdapter(jpaVendorAdapter());
          emfb.afterPropertiesSet();
          return emfb.getObject();
     }
}

Класс контроллера 

package com.example.demo.Controllers;

import java.util.List;

@Controller
public class TestController {

    private Logger logger = LoggerFactory.getLogger(TestController.class);


    private SingerDao dao;

    @GetMapping(value = "/hello")
    @ResponseBody
    public String sayHello(){
        return "Hello There";
    }

    @GetMapping(value ="/homepage")
    public String homepageListing(){
        return "homepage";
    }

    @GetMapping(value="/singers")
    public String listSingers(Model model){
        logger.info("Listing Singers:");
        List<Singer> singers = dao.findAll();
        String[] names = new String[singers.size()];
        for(int i = 0; i < names.length; i++){
            names[i] = singers.get(i).getFirstName();
        }
        model.addAttribute("singersNames", names);
        return "ListSingers";
    }

    @GetMapping(value="/getSinger{id}")
    public String getSingerById(Model model,@PathVariable Long id){
        model.addAttribute("singer", dao.findById(id).getFirstName());
        return "getSinger";
    }

    @Autowired
    public void setDao(SingerDao dao) {
        this.dao = dao;
    }
}

JpaRepository 

package com.example.demo.JpaRepo;


@Repository("jpaRepositoryImpl")
public class JpaRepositoryImpl implements JpaRepository {
    private EntityManagerFactory emf;

    @Override
    public List<Singer> findAll() {
        return emf.createEntityManager()
                .createQuery("select s from singer s")
                .getResultList();
    }

    @Override
    public Optional<Singer> findById(Long aLong) {
        return (Optional<Singer>) emf.createEntityManager().createQuery("select s from singer s where s.id = ?id").
                setParameter("id",aLong).getSingleResult();
    }

    @Autowired
    @Qualifier(value = "entityManagerFactory")
    public void setEmf(EntityManagerFactory emf) {
        this.emf = emf;
    }
}

Служба DAO 

package com.example.demo.DAO;


@Service("singerDaoImpl")
public class SingerDaoImpl implements SingerDao {

    private JpaRepository jpaRepo;

    @Override
    public List<Singer> findAll() {
        List<Singer> singers = new ArrayList<>();
        jpaRepo.findAll().forEach(item -> singers.add(item));
        System.out.println("# Of Singers: "+singers.size());
        return singers;
    }

    @Override
    public Singer findById(Long id) {
        return null;
    }

    @Autowired
    @Qualifier(value="jpaRepositoryImpl")
    public void setJpaRepo(JpaRepository jpaRepo) {
        this.jpaRepo = jpaRepo;
    }
}

Модель 

package com.example.demo.Model;

@Table(name="singer")
@Entity(name="singer")
public class Singer implements Serializable{

     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @Column(name="id")
     private Long id;

     @NotEmpty(message = "{validation.firstname.NotEmpty.message}")
     @Size(min=3,max=60,message="{validation.firstname.Size.message}")
     @Column(name="first_name")
     private String firstName;

     @NotEmpty(message = "{validation.lastname.NotEmpty.message}")
     @Size(min=3,max=60,message ="{validation.lastname.Size.message")
     @Column(name="last_name")
     private String lastName;

     @Temporal(TemporalType.DATE)
     @Column(name="birth_date")
     private Date birthDate;

     @Column(name="description")
     private String description;

     @Basic(fetch=FetchType.LAZY)
     @Lob
     @Column(name="photo")
     private byte photo;

     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 Date getDate() {
          return birthDate;
     }

     public void setDate(Date date) {
          this.birthDate = date;
     }

     public String getDescription() {
          return description;
     }

     public void setDescription(String description) {
          this.description = description;
     }

     public byte getPhoto() {
          return photo;
     }

     public void setPhoto(byte photo) {
          this.photo = photo;
     }

     @Transient
     public String getBirthDateString(){
          String birthDateString = "";
          if(birthDate != null){
               SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");
                    birthDateString = sdf.format(birthDate);
          }
          return birthDateString;
     }

     @Override
     public String toString() {
          return "Singer{" +
                  "id=" + id +
                  ", firstName='" + firstName + '\'' +
                  ", lastName='" + lastName + '\'' +
                  ", birthDate=" + birthDate +
                  ", description='" + description + '\'' +
                  ", photo=" + photo +
                  '}';
     }
}

Редактировать: Я добавил logging.level.org.springframework = debug Вот соответствующая часть консоли 

2020-05-26 11:26:13.500  INFO 14664 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2935 ms
2020-05-26 11:26:13.508 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'requestContextFilter'
2020-05-26 11:26:13.513 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'formContentFilter'
2020-05-26 11:26:13.513 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration'
2020-05-26 11:26:13.519 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'characterEncodingFilter'
2020-05-26 11:26:13.531 DEBUG 14664 --- [           main] o.s.b.w.s.ServletContextInitializerBeans : Mapping filters: characterEncodingFilter urls=[/*] order=-2147483648, formContentFilter urls=[/*] order=-9900, requestContextFilter urls=[/*] order=-105
2020-05-26 11:26:13.532 DEBUG 14664 --- [           main] o.s.b.w.s.ServletContextInitializerBeans : Mapping servlets: dispatcherServlet urls=[/]
2020-05-26 11:26:13.565 DEBUG 14664 --- [           main] o.s.b.w.s.f.OrderedRequestContextFilter  : Filter 'requestContextFilter' configured for use
2020-05-26 11:26:13.565 DEBUG 14664 --- [           main] s.b.w.s.f.OrderedCharacterEncodingFilter : Filter 'characterEncodingFilter' configured for use
2020-05-26 11:26:13.566 DEBUG 14664 --- [           main] o.s.b.w.s.f.OrderedFormContentFilter     : Filter 'formContentFilter' configured for use
2020-05-26 11:26:13.585 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'demoApplication'
2020-05-26 11:26:13.586 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'DBconfig'
2020-05-26 11:26:13.591 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.driverClassName' in PropertySource 'applicationConfig: [classpath:/application.properties]' with value of type String
2020-05-26 11:26:13.591 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.driverClassName' in PropertySource 'environmentProperties' with value of type String
2020-05-26 11:26:13.593 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.username' in PropertySource 'configurationProperties' with value of type String
2020-05-26 11:26:13.593 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.username' in PropertySource 'environmentProperties' with value of type String
2020-05-26 11:26:13.595 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.password' in PropertySource 'configurationProperties' with value of type String
2020-05-26 11:26:13.595 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.password' in PropertySource 'environmentProperties' with value of type String
2020-05-26 11:26:13.595 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.url' in PropertySource 'configurationProperties' with value of type String
2020-05-26 11:26:13.595 DEBUG 14664 --- [           main] o.s.c.e.PropertySourcesPropertyResolver  : Found key 'jdbc.url' in PropertySource 'environmentProperties' with value of type String
2020-05-26 11:26:13.599 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'testController'
2020-05-26 11:26:13.607 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'singerDaoImpl'
2020-05-26 11:26:13.614 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'jpaRepositoryImpl'
2020-05-26 11:26:13.621 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'entityManagerFactory'
2020-05-26 11:26:13.673 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'dataSourceE'
2020-05-26 11:26:13.702  INFO 14664 --- [           main] o.s.j.d.e.EmbeddedDatabaseFactory        : Starting embedded database: url='jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false', username='sa'
2020-05-26 11:26:13.712 DEBUG 14664 --- [           main] o.s.jdbc.datasource.DataSourceUtils      : Fetching JDBC Connection from DataSource
2020-05-26 11:26:13.713 DEBUG 14664 --- [           main] o.s.j.datasource.SimpleDriverDataSource  : Creating new JDBC Driver Connection to [jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false]
2020-05-26 11:26:13.971 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executing SQL script from class path resource [SQL/table.sql]
2020-05-26 11:26:14.002 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 0 returned as update count for SQL: CREATE TABLE SINGER ( ID INT NOT NULL AUTO_INCREMENT, FIRST_NAME VARCHAR(60), LAST_NAME VARCHAR(40), BIRTH_DATE DATE, DESCRIPTION VARCHAR(2000) NULL, PHOTO BLOB NULL, VERSION INT NOT NULL DEFAULT 0, UNIQUE UQ_SINGER_1 (FIRST_NAME, LAST_NAME), PRIMARY KEY (ID) )
2020-05-26 11:26:14.002 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executed SQL script from class path resource [SQL/table.sql] in 30 ms.
2020-05-26 11:26:14.002 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executing SQL script from class path resource [SQL/test.sql]
2020-05-26 11:26:14.014 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('John', 'Mayer', '1977-10-16')
2020-05-26 11:26:14.014 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Eric', 'Clampton', '1954-03-20')
2020-05-26 11:26:14.017 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('John', 'Butler', '1975-04-01')
2020-05-26 11:26:14.017 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('B.B' , 'King', '1925-09-16')
2020-05-26 11:26:14.019 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Jimi', 'Hendrix', '1942-11-27')
2020-05-26 11:26:14.021 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Eddie', 'Van Halen','1955-01-26')
2020-05-26 11:26:14.022 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Saul Slash', 'Hudson', '1965-07-23')
2020-05-26 11:26:14.023 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Stevie', 'Ray Vaughan','1954-10-03')
2020-05-26 11:26:14.023 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('David', 'Gilmour','1946-03-06')
2020-05-26 11:26:14.026 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Kirk','Hammett','1992-11-18')
2020-05-26 11:26:14.027 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Angus','Young','1955-03-31')
2020-05-26 11:26:14.028 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Dimebad','Darrell','1966-08-20')
2020-05-26 11:26:14.029 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : 1 returned as update count for SQL: INSERT INTO SINGER (FIRST_NAME, LAST_NAME, BIRTH_DATE) VALUES ('Carlos','Santana','1947-07-20')
2020-05-26 11:26:14.030 DEBUG 14664 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executed SQL script from class path resource [SQL/test.sql] in 28 ms.
2020-05-26 11:26:14.039 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker'
2020-05-26 11:26:14.043 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties'
2020-05-26 11:26:14.064 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Autowiring by type from bean name 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker' via constructor to bean named 'spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties'
2020-05-26 11:26:14.065 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Autowiring by type from bean name 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker' via constructor to bean named 'org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@456d6c1e'
2020-05-26 11:26:14.227 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'hibernaProperties'
2020-05-26 11:26:14.230 DEBUG 14664 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Creating shared instance of singleton bean 'jpaVendorAdapter'
2020-05-26 11:26:14.245 DEBUG 14664 --- [           main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2020-05-26 11:26:14.294  INFO 14664 --- [           main] o.hibernate.jpa.internal.util.LogHelper  : HHH000204: Processing PersistenceUnitInfo [name: default]
2020-05-26 11:26:14.412  INFO 14664 --- [           main] org.hibernate.Version                    : HHH000412: Hibernate ORM core version 5.4.15.Final
2020-05-26 11:26:14.685  INFO 14664 --- [           main] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
2020-05-26 11:26:14.906 DEBUG 14664 --- [           main] o.s.j.datasource.SimpleDriverDataSource  : Creating new JDBC Driver Connection to [jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false]
2020-05-26 11:26:14.940  INFO 14664 --- [           main] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
Hibernate:

SQL Запрос *

drop table if exists singer CASCADE 
2020-05-26 11:26:16.139 DEBUG 14664 --- [           main] o.s.j.datasource.SimpleDriverDataSource  : Creating new JDBC Driver Connection to [jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false]
Hibernate: 

    create table singer (
       id bigint generated by default as identity,
        birth_date date,
        description varchar(255),
        first_name varchar(255),
        last_name varchar(255),
        photo blob,
        primary key (id)
    )

Я нашел выражение 

javax.validation.NoProviderFoundException: Unable to create a Configuration, because no Bean Validation provider could be found. Add a provider like Hibernate Validator (RI) to your classpath.
    at javax.validation.Validation$GenericBootstrapImpl.configure(Validation.java:291) ~[validation-api-2.0.1.Final.jar:na]
    at org.springframework.validation.beanvalidation.LocalValidatorFactoryBean.afterPropertiesSet(LocalValidatorFactoryBean.java:257) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean.afterPropertiesSet(OptionalValidatorFactoryBean.java:40) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.afterPropertiesSet(ValidatorAdapter.java:83) ~[spring-boot-autoconfigure-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1306) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:539) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895) ~[spring-beans-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.0.RELEASE.jar:2.3.0.RELEASE]
    at com.example.demo.DemoApplication.main(DemoApplication.java:13) ~[main/:na]

1 Ответ

1 голос
/ 27 мая 2020

Вы были почти у цели. Фактически ваша база данных была пустой. Зачем? Из-за этой строки в вашем классе DBConfig. prop.put("hibernate.hbm2ddl.auto", "create-drop"); ( ссылка на документацию по этому свойству ). Вы можете безопасно удалить его или установить для свойства значение, которое имеет для вас смысл.

Вам также потребуется установить для атрибута photo (а также методов получения и установки для него) в вашем классе Singer значение Byte (Это тип типа также называется Wrapper Class ) вместо byte, поскольку byte - это примитивное значение, которое не может быть установлено в null. Однако в сценарии БД вы разрешаете photo иметь значение null, поэтому, если вы не измените этот код, это вызовет исключение при попытке сопоставить столбцы БД с объектами Java. Как только вы выберете эти две вещи, список певцов будет отображаться в браузере.

Теперь несколько последних советов, поскольку вы новичок в программировании и переполнении стека:

  1. Читать { ссылка } осторожно, если вы еще этого не сделали. Это поможет вам писать вопросы, на которые люди захотят ответить, и поможет избежать отрицательных голосов и увязки в stackoverflow.

  2. Я проверил ваше репо, и вы делаете много работы и настройки, которые вам не нужно делать, поскольку вы используете Spring Boot и Spring Boot Data Jpa, а не просто Spring. Я бы посоветовал вам сначала начать использовать Spring Boot в полной мере, а затем изучить Spring и способы его настройки в соответствии с вашими потребностями, если вам когда-либо понадобится только Spring для ваших нужд. Используйте эту ссылку в качестве шлюз, чтобы узнать больше о Spring Boot и Spring Boot Data Jpa.

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