我正在尝试使用外键创建两个联接表ConceptModelDetails和Instructions。以下是我的模型课程:
ConceptModel详细信息:
package com.assignment.model;
@Entity
@Table(name="conceptModelDetails")
public class ConceptModelDetails {
@Id @GeneratedValue(strategy=GenerationType.AUTO)
private int instructionsId;
private String operationType;
private String conceptModelID;
private String requestor;
private String status;
private Timestamp requestDateTime;
private Timestamp lastExecutedDateTime;
private Timestamp completedDateTime;
@OneToMany(cascade=CascadeType.ALL, mappedBy="conceptModelDetails")
private Set<Instructions> instructions;
public ConceptModelDetails() {}
}
和说明:
package com.assignment.model;
@Entity
@Table(name="instructions")
public class Instructions {
@Id
@GeneratedValue
private int Sno;
private String instruction;
@ManyToOne
@JoinColumn(name="instructionsId")
private ConceptModelDetails conceptModelDetails;
}
以下是applicationContext.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://192.168.1.79:5432/test" />
<property name="username" value="postgres" />
<property name="password" value="admin" />
</bean>
<bean id="objDAO" class="com.assignment.dao.impl.ConceptModelDAOImpl">
<property name="sessionFactory" ref="sessionfactory" />
</bean>
<bean id="sessionfactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="packagesToScan" value="com.assignment.model"></property>
<property name="annotatedClasses">
<list>
<value>com.assignment.model.ConceptModelDetails</value>
<value>com.assignment.model.Instructions</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.cache.use_second_level_cache">false</prop>
</props>
</property>
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionfactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
和控制器:
@RequestMapping(value = "/myCntrl", method = RequestMethod.POST)
public String handler(HttpServletRequest request) {
System.out.println("handler");
// System.out.println(request.getParameter("conceptID"));
// System.out.println(request.getParameter("operationType"));
String[] operations = request.getParameterValues("operations");
Date date = new Date();
Timestamp time = new Timestamp(date.getTime());
ConceptModelDetails conceptModelDetails = new ConceptModelDetails();
conceptModelDetails
.setConceptModelID(request.getParameter("conceptID"));
conceptModelDetails.setOperationType(request
.getParameter("operationType"));
conceptModelDetails.setRequestor(request.getParameter("requestor"));
conceptModelDetails.setRequestDateTime(time);
ApplicationContext context = new ClassPathXmlApplicationContext(
"applicationContext.xml");
System.out.println("yo");
ConceptModelDAO obj = (ConceptModelDAO)context.getBean("objDAO");
System.out.println("no");
Instructions instructions = new Instructions();
for(int i = 0; i < operations.length; i++){
instructions.setInstruction(operations[i]);
obj.addInstructions(instructions);
}
obj.add(conceptModelDetails);
return "success";
}
运行此代码时出现的问题是:
两个表都使用相同的hibernate_sequence。
如以下屏幕快照所示,外键未映射在指令表中。
请指导该代码出了什么问题。我是冬眠和春季的新手,所以希望您能得到详细的解释。提前致谢。
1)如果没有按JPA规范指定的生成器,则使用默认情况下休眠的全局序列生成器。
如下更改。对两个类都执行此操作,每个类的顺序不同。
@Entity
@SequenceGenerator(name="PRIVATE_SEQ", sequenceName="private_sequence")
public class ConceptModelDetails {
@Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="PRIVATE_SEQ")
private int instructionsId;
2)在这里Instructions
类拥有关系,因此,你应该设定ConceptModelDetails
目标为Instructions
保存前的对象Instructions
对象。
ConceptModelDetails cmd1 = new ConceptModelDetails();
Instructions i = new Instructions()
i.setConceptModelDetails(cmd1);
....
然后保存Instructions
对象i
希望这可以帮助。
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