我在尝试通过 URL 直接从 table 获取数据时收到 SQLGrammarException
I am getting a SQLGrammarException while trying to fetch data from table directly through URL
我正在使用 Apache Tomcat v9.0，当我在 运行 简单的 MVC 项目时出现错误。
- Alien.class
@Entity(name="alien")
public class Alien {
@Id
@Column(name="aid")
private int aid;
@Column(name="aname",length = 50)
private String aname;
public Alien(int aid, String aname) {
super();
this.aid = aid;
this.aname = aname;
}
public int getAid() {
return aid;
}
public void setAid(int aid) {
this.aid = aid;
}
public String getAname() {
return aname;
}
public void setAname(String aname) {
this.aname = aname;
}
@Override
public String toString() {
return "Alien [aid=" + aid + ", aname=" + aname + "]";
}
}
2.AlienDao
package com.example.OnlySpringMVCdemo.dao;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import com.example.springMVCdemo.models.Alien;
@Component
public class AlienDao {
@Autowired
private SessionFactory sessionFactory;
@Transactional
public List<Alien> getAlien(){
System.out.println("Inside getAliens method in DAO...");
Session session = sessionFactory.getCurrentSession();
System.out.println(session.createQuery("from alien", Alien.class).getQueryString());
List<Alien> aliens = session.createQuery("from alien",Alien.class).list();
System.out.println("the list is"+aliens);
return aliens;
}
}
3.HomeController
package com.example.OnlySpringMVCdemo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import com.example.OnlySpringMVCdemo.dao.AlienDao;
import com.example.springMVCdemo.models.Alien;
@Controller
public class HomeController {
@Autowired
private AlienDao dao;
@RequestMapping("/")
public String home() {
System.out.println("Home page requested");
return "index";
}
@ModelAttribute
public void modelData(Model m) {
m.addAttribute("name", "Piyush");
}
@GetMapping("getAliens")
public String getAliens(Model m) {
System.out.println("Inside the getAliens URL....");
m.addAttribute("result", dao.getAlien());
return "showAliens";
}
@RequestMapping("add")
/*public String add(HttpServletRequest req) {
int i = Integer.parseInt(req.getParameter("num1"));
int j = Integer.parseInt(req.getParameter("num2"));
int num3 = i+j;
HttpSession session = req.getSession();
session.setAttribute("num3", num3);
return "result.jsp";
}*/
/*public String add(@RequestParam("num1") int i,@RequestParam("num2")int j,HttpSession session) {
int num3= i+j;
session.setAttribute("num3", num3);
return "result.jsp";
}*/
/*
* public ModelAndView add(@RequestParam("num1") int i,@RequestParam("num2")int
* j) {
*
* ModelAndView mv = new ModelAndView(); mv.setViewName("result"); int num3 =
* i+j; mv.addObject("num3", num3); return mv; }
*/
//GetMethods
/*
* @RequestMapping(value="addAlien",method=RequestMethod.POST) public String
* addAlien(@ModelAttribute("alien") Alien a) {
* //System.out.println(a.getAid()+" "+a.getAname()); return "result";
* }
*/
@PostMapping(value="addAlien")
public String addAlien(@ModelAttribute("alien") Alien a) {
//System.out.println(a.getAid()+" "+a.getAname());
return "result";
}
}
4.dispatcherServlet-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:ctx="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<ctx:component-scan base-package="com.example.OnlySpringMVCdemo"></ctx:component-scan>
<ctx:annotation-config></ctx:annotation-config>
<!-- Configurations done to use ORM using Hibernate:-Start -->
<!-- Step 1: Define Database DataSource / connection pool -->
<bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="oracle.jdbc.driver.OracleDriver" />
<property name="jdbcUrl" value="jdbc:oracle:thin:@localhost:1521:orcldb"/>
<property name="user" value="piyush" />
<property name="password" value="admin" />
<!-- these are connection pool properties for C3P0 -->
<property name="minPoolSize" value="5" />
<property name="maxPoolSize" value="20" />
<property name="maxIdleTime" value="30000" />
</bean>
<!-- Step 2: Setup Hibernate session factory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
<property name="dataSource" ref="myDataSource" />
<property name="packagesToScan" value="com.example.springMVCdemo.models" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<!-- Step 3: Setup Hibernate transaction manager -->
<bean id="myTransactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<!-- Step 4: Enable configuration of transactional behavior based on annotations -->
<tx:annotation-driven transaction-manager="myTransactionManager"></tx:annotation-driven>
<!-- Add support for reading web resources: css, images, js, etc ... -->
<!-- <mvc:resources location="/resources/" mapping="/resources/**"></mvc:resources> -->
<!-- Configurations done to use ORM using Hibernate:-End -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
- web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
我试图在地址栏中简单地调用 URL http://localhost:8080/ORMMVC/getAliens，但出现以下错误：
HTTP Status 500 – Internal Server Error
Type Exception Report
Message Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:154)
org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
org.hibernate.query.spi.AbstractQuery.list(AbstractQuery.java:1365)
com.example.OnlySpringMVCdemo.dao.AlienDao.getAlien(AlienDao.java:23)
com.example.OnlySpringMVCdemo.dao.AlienDao$$FastClassBySpringCGLIB$172482.invoke(<generated>)
org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
com.example.OnlySpringMVCdemo.dao.AlienDao$$EnhancerBySpringCGLIB$0bf15f.getAlien(<generated>)
com.example.OnlySpringMVCdemo.HomeController.getAliens(HomeController.java:45)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
** 此问题的两个原因是：**
发生这种情况是因为 Hibernate 正在生成 HT_Alien table，这是一个临时的 table，其背后的原因是 Hibernate-core 版本 6.0.0 .Alpha3.
我在 Alien(Entity) 中没有默认构造函数 class
建议:
伙计们，请在使用 Hibernate 使用 ORM 时使用 hibernate 核心版本 5.4。1.Final。以下是相同的依赖项：
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.4.1.Final</version>
</dependency>
问题现已解决！！
我正在使用 Apache Tomcat v9.0，当我在 运行 简单的 MVC 项目时出现错误。
- Alien.class
@Entity(name="alien")
public class Alien {
@Id
@Column(name="aid")
private int aid;
@Column(name="aname",length = 50)
private String aname;
public Alien(int aid, String aname) {
super();
this.aid = aid;
this.aname = aname;
}
public int getAid() {
return aid;
}
public void setAid(int aid) {
this.aid = aid;
}
public String getAname() {
return aname;
}
public void setAname(String aname) {
this.aname = aname;
}
@Override
public String toString() {
return "Alien [aid=" + aid + ", aname=" + aname + "]";
}
}
2.AlienDao
package com.example.OnlySpringMVCdemo.dao;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import com.example.springMVCdemo.models.Alien;
@Component
public class AlienDao {
@Autowired
private SessionFactory sessionFactory;
@Transactional
public List<Alien> getAlien(){
System.out.println("Inside getAliens method in DAO...");
Session session = sessionFactory.getCurrentSession();
System.out.println(session.createQuery("from alien", Alien.class).getQueryString());
List<Alien> aliens = session.createQuery("from alien",Alien.class).list();
System.out.println("the list is"+aliens);
return aliens;
}
}
3.HomeController
package com.example.OnlySpringMVCdemo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import com.example.OnlySpringMVCdemo.dao.AlienDao;
import com.example.springMVCdemo.models.Alien;
@Controller
public class HomeController {
@Autowired
private AlienDao dao;
@RequestMapping("/")
public String home() {
System.out.println("Home page requested");
return "index";
}
@ModelAttribute
public void modelData(Model m) {
m.addAttribute("name", "Piyush");
}
@GetMapping("getAliens")
public String getAliens(Model m) {
System.out.println("Inside the getAliens URL....");
m.addAttribute("result", dao.getAlien());
return "showAliens";
}
@RequestMapping("add")
/*public String add(HttpServletRequest req) {
int i = Integer.parseInt(req.getParameter("num1"));
int j = Integer.parseInt(req.getParameter("num2"));
int num3 = i+j;
HttpSession session = req.getSession();
session.setAttribute("num3", num3);
return "result.jsp";
}*/
/*public String add(@RequestParam("num1") int i,@RequestParam("num2")int j,HttpSession session) {
int num3= i+j;
session.setAttribute("num3", num3);
return "result.jsp";
}*/
/*
* public ModelAndView add(@RequestParam("num1") int i,@RequestParam("num2")int
* j) {
*
* ModelAndView mv = new ModelAndView(); mv.setViewName("result"); int num3 =
* i+j; mv.addObject("num3", num3); return mv; }
*/
//GetMethods
/*
* @RequestMapping(value="addAlien",method=RequestMethod.POST) public String
* addAlien(@ModelAttribute("alien") Alien a) {
* //System.out.println(a.getAid()+" "+a.getAname()); return "result";
* }
*/
@PostMapping(value="addAlien")
public String addAlien(@ModelAttribute("alien") Alien a) {
//System.out.println(a.getAid()+" "+a.getAname());
return "result";
}
}
4.dispatcherServlet-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:ctx="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<ctx:component-scan base-package="com.example.OnlySpringMVCdemo"></ctx:component-scan>
<ctx:annotation-config></ctx:annotation-config>
<!-- Configurations done to use ORM using Hibernate:-Start -->
<!-- Step 1: Define Database DataSource / connection pool -->
<bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="oracle.jdbc.driver.OracleDriver" />
<property name="jdbcUrl" value="jdbc:oracle:thin:@localhost:1521:orcldb"/>
<property name="user" value="piyush" />
<property name="password" value="admin" />
<!-- these are connection pool properties for C3P0 -->
<property name="minPoolSize" value="5" />
<property name="maxPoolSize" value="20" />
<property name="maxIdleTime" value="30000" />
</bean>
<!-- Step 2: Setup Hibernate session factory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
<property name="dataSource" ref="myDataSource" />
<property name="packagesToScan" value="com.example.springMVCdemo.models" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<!-- Step 3: Setup Hibernate transaction manager -->
<bean id="myTransactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<!-- Step 4: Enable configuration of transactional behavior based on annotations -->
<tx:annotation-driven transaction-manager="myTransactionManager"></tx:annotation-driven>
<!-- Add support for reading web resources: css, images, js, etc ... -->
<!-- <mvc:resources location="/resources/" mapping="/resources/**"></mvc:resources> -->
<!-- Configurations done to use ORM using Hibernate:-End -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
- web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
我试图在地址栏中简单地调用 URL http://localhost:8080/ORMMVC/getAliens，但出现以下错误：
HTTP Status 500 – Internal Server Error
Type Exception Report
Message Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: JDBC exception executing SQL [select a1_0.aid, a1_0.aname from alien as a1_0]
org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:154)
org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
org.hibernate.query.spi.AbstractQuery.list(AbstractQuery.java:1365)
com.example.OnlySpringMVCdemo.dao.AlienDao.getAlien(AlienDao.java:23)
com.example.OnlySpringMVCdemo.dao.AlienDao$$FastClassBySpringCGLIB$172482.invoke(<generated>)
org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
com.example.OnlySpringMVCdemo.dao.AlienDao$$EnhancerBySpringCGLIB$0bf15f.getAlien(<generated>)
com.example.OnlySpringMVCdemo.HomeController.getAliens(HomeController.java:45)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
** 此问题的两个原因是：**
发生这种情况是因为 Hibernate 正在生成 HT_Alien table，这是一个临时的 table，其背后的原因是 Hibernate-core 版本 6.0.0 .Alpha3.
我在 Alien(Entity) 中没有默认构造函数 class
建议:
伙计们，请在使用 Hibernate 使用 ORM 时使用 hibernate 核心版本 5.4。1.Final。以下是相同的依赖项：
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.4.1.Final</version>
</dependency>
问题现已解决！！