我该如何解决这个问题??java.lang.ClassCastException

Question

白标错误页面
此应用程序没有/error 的显式映射，因此您将其视为回退。

周一 8月 13 21：40：42 EEST 2018
出现意外错误(类型=内部服务器错误，状态=500(。
DataBaseTest.Instructor 不能强制转换为 DataBaseTest.Instructor

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import DataBaseTest.Instructor;
@RestController
public class TestWebService {
@Autowired
private  SessionFactory sessionFactory ;
@GetMapping(path="/user")
public Instructor getUser(){
Session session = sessionFactory.getCurrentSession();
session.beginTransaction();
Instructor instructor = (Instructor) session.get(Instructor.class,1);
System.out.println(instructor);
return instructor;
}

----------------------------班教官------------------------

@Entity
@Table(name="instructor")
public class Instructor {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private int id ;
@Column(name="first_name")
private String firstName ;
@Column(name="last_name")
private String lastName ;
@Column(name="email")
private String email ;
@OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="instructor_detail_id")
InstructorDetails instructorDetails ;
public Instructor(){
}
public Instructor(String firstName, String lastName, String email) {
super();
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
public int getId() {
return id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public InstructorDetails getInstructorDetails() {
return instructorDetails;
}
public void setInstructorDetails(InstructorDetails instructorDetails) {
this.instructorDetails = instructorDetails;
}
@Override
public String toString() {
return "Instructor [id=" + id + ", firstName=" + firstName + ", lastName=" + lastName + ", email=" + email
+ ", instructorDetails=" + instructorDetails + "]";
}

}

----------------------------班讲师详细信息------------------------

@Entity
@Table(name="instructor_detail")
public class InstructorDetails {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private int id ;
@Column(name="youtube_channel")
private String youtubeChanel ;
@Column(name="hobby")
private String hobby ;
public InstructorDetails(){
}
public InstructorDetails(String youtubeChanel, String hobby) {
super();
this.youtubeChanel = youtubeChanel;
this.hobby = hobby;
}
public int getId() {
return id;
}
public String getYoutubeChanel() {
return youtubeChanel;
}
public void setYoutubeChanel(String youtubeChanel) {
this.youtubeChanel = youtubeChanel;
}
public String getHobby() {
return hobby;
}
public void setHobby(String hobby) {
this.hobby = hobby;
}
@Override
public String toString() {
return "InstructorDetails [id=" + id + ", youtubeChanel=" + youtubeChanel + ", hobby=" + hobby + "]";
}

}

---------------------------应用----------------

@SpringBootApplication
public class Application {
public SessionFactory getSessionFactory() {
return new Configuration().configure("hibernate.cfg2.xml").
addAnnotatedClass(Instructor.class).addAnnotatedClass(InstructorDetails.class).
buildSessionFactory();
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

-----------------------------hibernate.cfg2.xml------------------------------

<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- JDBC Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/hb-01-one-to-one-uni?useSSL=false</property>
<property name="connection.username">hbstudent</property>
<property name="connection.password">hbstudent</property>
<!-- JDBC connection pool settings ... using built-in test pool -->
<property name="connection.pool_size">100</property>
<!-- Select our SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Echo the SQL to stdout -->
<property name="show_sql">true</property>
<!-- Set the current session context -->
<property name="current_session_context_class">thread</property>
</session-factory>
</hibernate-configuration>

---

2018-08-14 11:27:48.429  INFO 6924 --- [  restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$af5c7f54] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2018-08-14 11:27:49.520  INFO 6924 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2018-08-14 11:27:49.559  INFO 6924 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2018-08-14 11:27:49.560  INFO 6924 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/9.0.10
2018-08-14 11:27:49.580  INFO 6924 --- [  restartedMain] o.a.catalina.core.AprLifecycleListener   : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:Program FilesJavajre1.8.0_144bin;C:WindowsSunJavabin;C:Windowssystem32;C:Windows;C:/Program Files/Java/jre1.8.0_144/bin/server;C:/Program Files/Java/jre1.8.0_144/bin;C:/Program Files/Java/jre1.8.0_144/lib/amd64;C:ProgramDataOracleJavajavapath;C:Program FilesDellDW WLAN Card;C:Windowssystem32;C:Windows;C:WindowsSystem32Wbem;C:WindowsSystem32WindowsPowerShellv1.0;c:Program FilesWIDCOMMBluetooth Software;c:Program FilesWIDCOMMBluetooth Softwaresyswow64;C:Program FilesMicrosoft SQL Server110ToolsBinn;C:Program Files (x86)GtkSharp2.12bin;C:Program FilesMicrosoftWeb Platform Installer;C:Program Files (x86)Microsoft ASP.NETASP.NET Web Pagesv1.0;C:Program Files (x86)Windows Kits8.0Windows Performance Toolkit;C:Program FilesGitcmd;%M2_HOME%bin;E:DepartmentJavagradle-4.7bin;D:;E:apache-maven-3.1.1bin ;C:UsersMohammed MarsAppDataRoamingnpm;E:eclipse;;.]
2018-08-14 11:27:49.776  INFO 6924 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2018-08-14 11:27:49.776  INFO 6924 --- [  restartedMain] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 4625 ms
2018-08-14 11:27:49.858  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.ServletRegistrationBean  : Servlet dispatcherServlet mapped to [/]
2018-08-14 11:27:49.862  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.ServletRegistrationBean  : Servlet webServlet mapped to [/h2-console/*]
2018-08-14 11:27:49.868  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-08-14 11:27:49.869  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-08-14 11:27:49.869  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-08-14 11:27:49.869  INFO 6924 --- [  restartedMain] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-08-14 11:27:50.295  INFO 6924 --- [  restartedMain] org.hibernate.Version                    : HHH000412: Hibernate Core {5.3.3.Final}
2018-08-14 11:27:50.300  INFO 6924 --- [  restartedMain] org.hibernate.cfg.Environment            : HHH000206: hibernate.properties not found
2018-08-14 11:27:50.619  INFO 6924 --- [  restartedMain] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.0.4.Final}
2018-08-14 11:27:50.818  WARN 6924 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001002: Using Hibernate built-in connection pool (not for production use!)
2018-08-14 11:27:50.821  INFO 6924 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001005: using driver [null] at URL [jdbc:mysql://localhost:3306/hb-01-one-to-one-uni?useSSL=false]
2018-08-14 11:27:50.822  INFO 6924 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001001: Connection properties: {user=hbstudent, password=****}
2018-08-14 11:27:50.822  INFO 6924 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001003: Autocommit mode: false
2018-08-14 11:27:50.827  INFO 6924 --- [  restartedMain] .c.i.DriverManagerConnectionProviderImpl : HHH000115: Hibernate connection pool size: 1 (min=1)
2018-08-14 11:27:51.099  INFO 6924 --- [  restartedMain] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
2018-08-14 11:27:52.413  INFO 6924 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService  'applicationTaskExecutor'
2018-08-14 11:27:52.964  WARN 6924 --- [  restartedMain] aWebConfiguration$JpaWebMvcConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
2018-08-14 11:27:53.456  INFO 6924 --- [  restartedMain] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2018-08-14 11:27:53.816  INFO 6924 --- [  restartedMain] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
2018-08-14 11:27:54.228  INFO 6924 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
2018-08-14 11:27:54.719  INFO 6924 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2018-08-14 11:27:54.737  INFO 6924 --- [  restartedMain] c.Q.mars.E3lnle_Project.V3.Application   : Started Application in 10.557 seconds (JVM running for 11.825)
2018-08-14 11:28:07.217  INFO 6924 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2018-08-14 11:28:07.217  INFO 6924 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2018-08-14 11:28:07.253  INFO 6924 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 36 ms
Hibernate: select instructor0_.id as id1_0_0_, instructor0_.email as email2_0_0_, instructor0_.first_name as first_na3_0_0_, instructor0_.instructor_detail_id as instruct5_0_0_, instructor0_.last_name as last_nam4_0_0_, instructor1_.id as id1_1_1_, instructor1_.hobby as hobby2_1_1_, instructor1_.youtube_channel as youtube_3_1_1_ from instructor instructor0_ left outer join instructor_detail instructor1_ on instructor0_.instructor_detail_id=instructor1_.id where instructor0_.id=?
2018-08-14 11:28:07.919 ERROR 6924 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: DataBaseTest.Instructor cannot be cast to DataBaseTest.Instructor] with root cause
java.lang.ClassCastException: DataBaseTest.Instructor cannot be cast to DataBaseTest.Instructor
at com.Quraan.mars.E3lnle_Project.V3.webService.TestWebService.getUser(TestWebService.java:27) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_144]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_144]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_144]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:207) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:799) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1041) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1012) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:904) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:889) ~[spring-webmvc-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:112) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.1.0.BUILD-SNAPSHOT.jar:5.1.0.BUILD-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:491) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:764) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1388) [tomcat-embed-core-9.0.10.jar:9.0.10]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.10.jar:9.0.10]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_144]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_144]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.10.jar:9.0.10]
at java.lang.Thread.run(Unknown Source) [na:1.8.0_144]

Answer 1

我能想到的唯一可能的解释是，这是 https://stackoverflow.com/a/6184448/1039555 中所述的类加载器泄漏。

请参阅该答案中的评论：-

@Musa YUVACI - 这种形式的类加载器泄漏通常是由于 引用保存在服务器范围的类加载器中(要么是 应用服务器或开发人员在 WAR/EAR 之外添加库。– 麦克道尔 五月 31 '11 在 9：08

@McDowel-感谢您的回复，它现在可以工作了。 在 WAR 外部添加库时出现问题。所以之后 从 GlassFish 服务器中删除库，它可以工作。- 穆萨·尤瓦奇 五月 31 '11 在 13：35