Question

我最近开始研究springBoot项目。我写了一个示例程序，我从数据库中获取数据，修改它并将其存储回数据库。

我面临的问题是，我能够从数据库中获取数据，但在保存时，我得到以下异常。

import java.util.Properties;


import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;

import org.springframework.transaction.annotation.EnableTransactionManagement;
/**
 * 
 * This class contains code to configure database. 
 * @author satish
 *
 */
@Configuration
@EntityScan(basePackages= {"com.tushar.common.model"})
@ComponentScan(basePackages= {"com.tushar.common.model"})
@EnableJpaRepositories(basePackages={"com"})
@EnableTransactionManagement 
public class DataConfiguration {

    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;

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

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

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

    @Value("${spring.datasource.dialect}")
    private String dialect;

    /**
     * 
     * It will scan the package where our entities appears.
     * @param dataSource
     * @return
     */
    @Bean
    @Autowired
    public LocalContainerEntityManagerFactoryBean  entityManagerFactory(DataSource dataSource) {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);

        Properties jpaProperties = new Properties();
        jpaProperties.setProperty("hibernate.show_sql", "true");
        jpaProperties.setProperty("hibernate.dialect", dialect);
        jpaProperties.setProperty("hibernate.hbm2ddl.auto", "update");

        LocalContainerEntityManagerFactoryBean localContainerEntityManagerFactoryBean = 
                new LocalContainerEntityManagerFactoryBean();
        localContainerEntityManagerFactoryBean.setJpaVendorAdapter(vendorAdapter);
        localContainerEntityManagerFactoryBean.setPackagesToScan(new String[]  {"com.att.pricerd.discountmanagement.model"});
        localContainerEntityManagerFactoryBean.setDataSource(dataSource);

       localContainerEntityManagerFactoryBean.setJpaProperties(jpaProperties);



        return localContainerEntityManagerFactoryBean;
    }
    /**
     * 
     * It will set the database properties to the data Source.
     * @return
     */
    @Bean
    public DataSource dataSource(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean
    @Autowired
    public JpaTransactionManager transactionManager(LocalContainerEntityManagerFactoryBean emf) throws Exception {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(emf.getObject());
    transactionManager.setEntityManagerFactory(emf.getNativeEntityManagerFactory());
    return transactionManager;
    }

}

以下是我的代码。 DataConfiguraiton.java

@Repository
public interface EmployeeRepository extends JpaRepository<Employee,Long> {

}

存储库

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class EmployeeDataManagementDaoImpl implements EmployeeDataManagementDao {

    private static final Logger LOG = LoggerFactory.getLogger(EmployeeDataManagementDaoImpl.class);

    @Autowired
    private EmployeeDataManagmentUtil EmployeeDataManagmentUtil;

    @Autowired
    private SalesEmployeesRepository salesEmployeesRepository;

    @Autowired
    private EmployeeRepository employeeRepository;

    @PersistenceContext
    private EntityManager em;

    @Override
    public void addEmployee(EmployeeDetailsRequestVo EmployeeRequest) {
        convertAndSaveSalesEmployee(EmployeeRequest);
    }

    /**
     * Fetch data from DB, update the inital and maximum Employee and
     * save it back to DB. 
     * @throws DataNotFoundException
     * 
     */
    @Override
    public void changeEmployee(List<Employee> Employees) throws EmployeeManagementException {
        for (Employee employee : Employees) {

            List<Employee> EmployeesDB;
            try {
                EmployeesDB = getEmployeeFromDB(employee);
            } catch (DataNotFoundException e) {
                List<String> errorMessage = new ArrayList<>();
                errorMessage.add(e.getMessage());
                LOG.error(e.getMessage(),e);
                throw new EmployeeManagementException(errorMessage);
            }

            for (Employee employee : EmployeesDB) {
                if (employee.getMaxEmployee() != null) {
                    Employee.setMaxEmployee(employee.getMaxEmployee());
                }
                if (employee.getInitialEmployee() != null) {
                    Employee.setInitialEmployee(employee.getInitialEmployee());
                }
                employeeRepository.saveAndFlush(Employee);
            }
        }

    }

    /**
     * This method is used to get the Employee details from DB.
     * 
     * @param employee
     * @return List<Employee>
     * @throws DataNotFoundException
     */
    private List<Employee> getEmployeeFromDB(Employee employee)
            throws DataNotFoundException {
        List<Employee> EmployeesDB = findByAllEmployeesFilters(employee.getempId(),
                employee.getyearsExp(), employee.getdeptLevInd(), employee.getsalary(),
                employee.getaddress(), employee.getCountryCd(), employee.getpinCode());

        if (EmployeesDB.isEmpty()) {
            String errCode = ""; // error code for data not found, yet to be
                                    // decided.
            LOG.error("ERROR CODE :: {}", errCode);
            throw new DataNotFoundException(errCode);
        }
        return EmployeesDB;
    }

    /**
     * This method will update the end date Employee
     * @param List<Employee>
     */
    @Override
    public void inactivateEmployee(List<Employee> Employees)
            throws EmployeeManagementException {
        for (Employee employee : Employees) {

            List<Employee> employeesDB;
            try {
                employeesDB = getEmployeeFromDB(employee);
            } catch (DataNotFoundException e) {
                List<String> errorMessage = new ArrayList<>();
                errorMessage.add(e.getMessage());
                LOG.error(e.getMessage(),e);
                throw new EmployeeManagementException(errorMessage);
            }
            for (Employee employee : EmployeesDB) {
                if (employee.getEmployeeEndDate() != null) {
                    employee.setEmployeeEndDate(employee.getEmployeeEndDate());
                }
                //
                employeeRepository.saveAndFlush(Employee);
            }
        }
    }

    /**
     * 
     * @param empId
     * @param yearsExp
     * @param bigDecimal
     * @param salary
     * @param regionId
     * @param countryCd
     * @param pinCode
     * @return
     */
    private List<Employee> findByAllEmployeeFilters(BigDecimal empId, BigDecimal yearsExp,
            BigDecimal bigDecimal, BigDecimal salary, String regionId, String countryCd, String pinCode) {
        CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
        CriteriaQuery<Employee> criteriaQuery = criteriaBuilder
                .createQuery(Employee.class);
        Root<Employee> root = criteriaQuery.from(Employee.class);

        criteriaQuery.where(criteriaBuilder.equal(root.get("empId"), empId),
                criteriaBuilder.equal(root.get("deptLevInd"), bigDecimal),
                criteriaBuilder.equal(root.get("yearsExp"), yearsExp), criteriaBuilder.equal(root.get("salary"), salary),
                criteriaBuilder.equal(root.get("address"), regionId),
                criteriaBuilder.equal(root.get("countryCd"), countryCd),
                criteriaBuilder.equal(root.get("pinCode"), pinCode));


        return em.createQuery(criteriaQuery).getResultList();
    }

}

DAO课程

getEmployeeFromDB

import slick.jdbc.PostgresProfile.api._ import scala.concurrent.Await import scala.concurrent.ExecutionContext.Implicits.global import scala.concurrent.duration._ object Main { case class Song( id: Int, name: String, singer: String) class SongsTable(tag: Tag) extends Table[Song](tag, "songs") { def id = column[Int]("id") def name = column[String]("name") def singer = column[String]("singer") def * = (id, name, singer) <> (Song.tupled, Song.unapply) } val db = Database.forConfig("scalaxdb") val songs = TableQuery[SongsTable] def main(args: Array[String]): Unit = { Await.result({ db.run(songs.result).map(_.foreach(row => println("song with id " + row.id + " has name " + row.name + " and a singer is " + row.singer))) }, 1 minute) } }从DB获取值，但saveAndFlush给了我异常。

Answer 1

Actualy Bedla很严格，你应该使用@Transactional。我想添加的方法changeEmployee应该在Service类中声明。正确的设计是创建EmployeeService类并将方法changeEmployee移动到它，并使用@Transactional注释服务。 Generaly dao应该只包含要从db加载的find方法和要保存的更新/保存方法。

springboot app中的事务管理

1 个答案: