Spring休眠mysql一对多答案

【问题标题】：Spring hibernate mysql one to manySpring休眠mysql一对多
【发布时间】：2014-05-05 06:08:16
【问题描述】：

https://github.com/ruoli/SpringHibernateMysql

我正在尝试使用 spring mvc 和 hibernate 实现“一对多”映射。同时，我的一对一映射运行良好。但只要我添加另一个实体：

private List<Projects> project

pom.xml

<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>Main</groupId>
    <artifactId>Spring-Hibernate-Mysql</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Spring-Hibernate-Mysql</name>
    <url>http://maven.apache.org</url>

    <properties>
        <spring.version>3.2.0.RELEASE</spring.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.2.2</version>
        </dependency>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>persistence-api</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.1.9.Final</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>SpringApp</finalName>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <includes>
                        <include>**/*Tests.java</include>
                    </includes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

@OneToMany
private List<Projects> projects;

一切都崩溃了。这是我的一对多的代码：

员工模型：

@Entity
@Table(name = "EMPLOYEE")
public class Employee {

@Id
@Column(name = "ID", nullable = false)
private String id;

@Column(name = "NAME", nullable = false)
private String name;

@Column(name = "AGE", nullable = false)
private long age;

private List<Projects> projects;


public Employee() {
}

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public long getAge() {
    return age;
}

public void setAge(long age) {
    this.age = age;
}


@OneToMany(mappedBy="employee")
public List<Projects> getProjects() {
    return projects;
}

public void setProjects(List<Projects> projects) {
    this.projects = projects;
}
}

项目模型：

@Entity
@Table(name = "PROJECTS")
public class Projects {

private Employee employee;

@Column(name = "PROJECT_TITLE", nullable = false)
private String projectTitle;

@Column(name = "PROJECT_TYPE", nullable = false)
private String projectType;

public Projects(){

}

@ManyToOne
@JoinColumn(name = "id")
public Employee getEmployee() {
    return employee;
}

public void setEmployee(Employee employee) {
    this.employee = employee;
}

public String getProjectTitle() {
    return projectTitle;
}

public void setProjectTitle(String projectTitle) {
    this.projectTitle = projectTitle;
}

public String getProjectType() {
    return projectType;
}

public void setProjectType(String projectType) {
    this.projectType = projectType;
}
}

员工道：

public interface EmployeeDAO {
void persistEmployee(Employee employee);

Employee findEmployeeById(String id);

void updateEmployee(Employee employee);

void deleteEmployee(Employee employee);

}

EmployeeDAOImpl：

@Repository("employeeDAO")
public class EmployeeDAOImpl implements EmployeeDAO {

@Autowired
private SessionFactory sessionFactory;

@Override
public void persistEmployee(Employee employee) {
    sessionFactory.getCurrentSession().persist(employee);
}

@Override
public Employee findEmployeeById(String id) {
    return (Employee) sessionFactory.getCurrentSession().get(Employee.class, id);
}

@Override
public void updateEmployee(Employee employee) {
    sessionFactory.getCurrentSession().update(employee);

}
@Override
public void deleteEmployee(Employee employee) {
    sessionFactory.getCurrentSession().delete(employee);

}

}

员工服务：

public interface EmployeeService {
    void persistEmployee(Employee employee);

    Employee findEmployeeById(String id);

    void updateEmployee(Employee employee);

    void deleteEmployee(Employee employee);
}

EmployeeServiceImpl：

@Service("employeeService")
public class EmployeeServiceImpl implements EmployeeService{

    @Autowired
    EmployeeDAO employeeDAO;

    @Override
    @Transactional
    public void persistEmployee(Employee employee) {
        employeeDAO.persistEmployee(employee);

    }

    @Override
    @Transactional
    public void updateEmployee(Employee employee) {
        employeeDAO.updateEmployee(employee);

    }
    @Override
    @Transactional
    public Employee findEmployeeById(String id) {
        return employeeDAO.findEmployeeById(id);
    }

    @Override
    @Transactional
    public void deleteEmployee(Employee employee) {
        employeeDAO.deleteEmployee(employee);

    }

}

最后，这是运行程序的主要部分：

public class HelloApp {
    public static void main(String[] args) {
        System.out.println("load context");
        ConfigurableApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");

        Projects johnsproject= new Projects();
        johnsproject.setId("123");
        johnsproject.setProjectTitle("APP project");
        johnsproject.setProjectType("IOS");

        List<Projects> projectList = new ArrayList<Projects>();
        projectList.add(johnsproject);


        Employee em = new Employee();
        em.setId("88");
        em.setName("pj0");
        em.setAge(41);
        em.setProjects(projectList);

        EmployeeService emService = (EmployeeService) context.getBean("employeeService");

        emService.persistEmployee(em);
        System.out.println("Updated age :" + emService.findEmployeeById("88").getAge());

        em.setAge(53);
        emService.updateEmployee(em);
        System.out.println("Updated age :" + emService.findEmployeeById("88").getAge());

        emService.deleteEmployee(em);

        context.close();
    }
}

还有我的 spring hibernate 配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
        xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
        xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:task="http://www.springframework.org/schema/task"
        xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd">

    <context:component-scan base-package="com.lee.*"/>

    <tx:annotation-driven/>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:8889/test" />
        <property name="username" value="root" />
        <property name="password" value="root" />
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="annotatedClasses">
            <list>
                <value>com.lee.Model.Employee</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop
                        key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"
          p:sessionFactory-ref="sessionFactory">
    </bean>

</beans>

这就是它所抱怨的：

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.lee.DAO.EmployeeDAOImpl.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [spring-config.xml]: Invocation of init method failed; nested exception is java.lang.NoSuchMethodError: javax.persistence.OneToMany.orphanRemoval()Z

我已经花了一整天的时间试图弄清楚如何使用 spring hibernate 进行一对多映射，epic fail >。

【问题讨论】：

java.lang.NoSuchMethodError: javax.persistence.OneToMany.orphanRemoval() - 你的类路径中缺少什么吗？
刚刚也将 pom.xml 添加到这个问题线程中......这就是我为这个练习项目所拥有的所有代码，我整天都在试图找出问题所在......没有 clud-.-

标签： mysql database spring hibernate mapping

【解决方案1】：

更新 Employee bean 以实现与项目列表的一对多映射

private List<Projects> projects;


@OneToMany(mappedBy="employee")
public List<Projects> getProjects() {
    return projects;
}

public void setProjects(List<Projects> projects) {
    this.projects = projects;
}

然后通过加入员工 ID 来更新 Project Bean 以添加引用

private Employee employee;
@ManyToOne
@JoinColumn(name = "id")
public Employee getEmployee() {
    return employee;
}
public void setEmployee(Employee employee) {
    this.employee = employee;
}

【讨论】：

线程“main”中的异常 org.springframework.beans.factory.BeanCreationException：创建名为“employeeDAO”的 bean 时出错：注入自动装配的依赖项失败；嵌套异常是 org.springframework.beans.factory.BeanCreationException：无法自动装配字段：私有 org.hibernate.SessionFactory com.lee.DAO.EmployeeDAOImpl.sessionFactory；嵌套异常是 org.springframework.beans.factory.BeanCreationException：在类路径资源 [spring-config.xml] 中定义名称为“sessionFactory”的 bean 创建时出错：
init 方法调用失败；嵌套异常是 org.hibernate.AnnotationException: No identifier specified for entity: com.lee.Model.Projects
我还根据您建议我更改的那个修改了我的初始邮政编码......仍然有这些错误。