我不知道下面的代码有什么问题。如果我点击浏览器的请求，它就可以正常工作。但是当我发出并发请求时，它失败并提示 session 已关闭!。我同时或同时访问以下两个网址(异步调用)。
http://localhost:8080/getEmployee
http://localhost:8080/getDepartment
Controller .java
@RequestMapping(value = "/getEmployees", method = RequestMethod.POST)
public @ResponseBody List<Employee> getEmployee() {
List<Employee> empList = null;
empList = services.getEmployee();
return empList;
}
@RequestMapping(value = "/getDepartments", method = RequestMethod.GET)
public @ResponseBody List<Department> getDepartment() {
List<Department> deptList = null;
deptList = services.getDepartment();
return deptList;
}
两个模型类
Table 1 (Employee)
@Entity
@Table(name = "employee")
public class Employee implements java.io.Serializable {
private static final long serialVersionUID = 2650114334774359089L;
@Id
@Column(name = "id", unique = true, nullable = false, length = 100)
private String id;
@Column(name = "name", unique = true, nullable = false, length = 50)
private String name;
// getter setter
//第二个模型类
Table 2 (Department)
@Entity
@Table(name = "department")
public class Department implements java.io.Serializable {
private static final long serialVersionUID = 2650114334774359089L;
@Id
@Column(name = "id", unique = true, nullable = false, length = 100)
private String id;
@Column(name = "dept_name", unique = true, nullable = false, length = 50)
private String dept_name;
// getter setter
DAOImpl
@Autowired
SessionFactory sessionFactory;
Session session = null;
Transaction tx = null;
static final Logger LOGGER = Logger.getLogger(DataDaoImpl.class);
public List<Employee> getEmployee() throws Exception {
List<Employee> result = null;
session = sessionFactory.openSession();
String hql = "from Employee";
Query lQuery = session.createQuery(hql);
result = lQuery.list();
tx = session.getTransaction();
session.beginTransaction();
tx.commit();
return result;
}
public List<Department> getDepartment() throws Exception {
List<Department> result = null;
session = sessionFactory.openSession();
String hql = "from Department";
Query lQuery = session.createQuery(hql);
result = lQuery.list();
tx = session.getTransaction();
session.beginTransaction();
tx.commit();
return result;
}
服务实现
@Override
public List<Employee> getEmployee() throws Exception {
return dataDao.getEmployee();
}
@Override
public List<Department> getDepartment() throws Exception {
return dataDao.getDepartment();
}
spring-config.xml
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/mydb" />
<property name="username" value="root" />
<property name="password" value="password"/>
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="annotatedClasses">
<list>
<value>com.srdh.model.Employee</value>
<value>com.srdh.model.Department</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
</bean>
<bean id="txManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
<bean id="dataDao" class="com.test.dao.DaoImpl"></bean>
<bean id="dataServices" class="com.test.service.ServicesImpl"></bean>
任何人都可以帮我解决我在代码中做错的事情吗？我只有一个 DAO 来访问部门表和员工表。我必须从各个表中获取记录并在输出中显示。在并发请求中它失败了。
错误堆栈跟踪
org.hibernate.HibernateException: createQuery is not valid without active transaction
at org.hibernate.context.internal.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:352)
at com.sun.proxy.$Proxy139.createQuery(Unknown Source)
at com.srdh.dao.DataDaoImpl.getDepartment(DataDaoImpl.java:49)
at com.srdh.service.DataServicesImpl.getDepartment(DataServicesImpl.java:26)
at com.srdh.controller.MainController.getDepartment(MainController.java:44)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
org.hibernate.SessionException: Session is closed!
at org.hibernate.internal.AbstractSessionImpl.errorIfClosed(AbstractSessionImpl.java:133)
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1433)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.hibernate.context.internal.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:356)
at com.sun.proxy.$Proxy139.beginTransaction(Unknown Source)
at com.srdh.dao.DataDaoImpl.Employee(DataDaoImpl.java:126)
at com.srdh.service.DataServicesImpl.Employee(DataServicesImpl.java:71)
at com.srdh.controller.MainController.Employee(MainController.java:73)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:958)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:452)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
org.hibernate.TransactionException: nested transactions not supported
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:154)
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1435)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
最佳答案
错误堆栈跟踪显示createQuery在没有 Activity 事务的情况下无效，从中我们可以看到没有 Activity 事务，换句话说，没有打开的事务，这是因为您创建并执行了query 在打开交易之前。
所以你最大的错误是你在打开任何事务之前查询数据库。
您需要移动:
tx = session.getTransaction();
session.beginTransaction();
在创建和执行查询的行之前。
并且您在每个请求中使用新的 Session，您应该使用 sessionFactory.getCurrentSession() 而不是 sessionFactory.openSession() .
所以你需要像这样更新你的代码:
public List<Employee> getEmployee() throws Exception {
List<Employee> result = null;
Session session = sessionFactory.getCurrentSession();
Transaction tx = session.getTransaction();
session.beginTransaction();
String hql = "from Employee";
Query lQuery = session.createQuery(hql);
result = lQuery.list();
tx.commit();
return result;
}
public List<Department> getDepartment() throws Exception {
List<Department> result = null;
Session session = sessionFactory.getCurrentSession();
Transaction tx = session.getTransaction();
session.beginTransaction();
String hql = "from Department";
Query lQuery = session.createQuery(hql);
result = lQuery.list();
tx.commit();
return result;
}
这应该可以解决您的问题。
注意:
正如 @SergeBallesta 所报告和指出的那样，您不应该使用 session 和 tx 作为 DAO 中的实例变量，您最好使用它们作为方法中的局部变量，就像我上面的代码一样。
关于java - 并发请求失败 - "Session is closed!"，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43091560/