java.lang.NoClassDefFoundError: Could not initialize class com.dao.UserDAO

Question

我正在尝试制作这个 link 的项目：http://uaihebert.com/full-web-application-with-tomcat-jsf-primefaces-jpa-hibernate/ 当我尝试 运行 这个应用程序时，出现这个错误：

javax.faces.el.EvaluationException: java.lang.NoClassDefFoundError: Could not initialize class com.dao.UserDAO at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) at javax.faces.component.UICommand.broadcast(UICommand.java:315) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) at com.filter.LoginCheckFilter.doFilter(LoginCheckFilter.java:61) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282) at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167) at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201) at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175) at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235) at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201) at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133) at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112) at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561) at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access0(WorkerThreadIOStrategy.java:56) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NoClassDefFoundError: Could not initialize class com.dao.UserDAO at com.facade.UserFacade.(UserFacade.java:17) at com.mb.LoginMB.login(LoginMB.java:45) 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:483) at com.sun.el.parser.AstValue.invoke(AstValue.java:289) at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304) at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105) at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87) ... 41 more

UserDAO:

public class UserDAO extends GenericDAO<User> {

   private static final long serialVersionUID = 1L;

   public UserDAO() {
       super(User.class);
   }

   public User findUserByEmail(String email) {
       Map<String, Object> parameters = new HashMap<String, Object>();
       parameters.put("email", email);

       return super.findOneResult(User.FIND_BY_EMAIL, parameters);
   }
}

用户外观：

public class UserFacade {
   private UserDAO userDAO = new UserDAO();

    public User isValidLogin(String email, String password) {
        userDAO.beginTransaction();
        User user = userDAO.findUserByEmail(email);

        if (user == null || !user.getPassword().equals(password)) {
            return null;
        }

        return user;
   }
}

用户：

@Entity
@Table(name = "USERS")
@NamedQuery(name = "User.findUserByEmail", query = "select u from User u where u.email = :email")
public class User implements Serializable {

   private static final long serialVersionUID = 1L;

   public static final String FIND_BY_EMAIL = "User.findUserByEmail";

   @Id
   @GeneratedValue(strategy = GenerationType.AUTO)
   private int id;

   @Column(unique = true)
   private String email;
   private String password;
   private String name;
   @Enumerated(EnumType.STRING)
   private Role role;

   public int getId() {
       return id;
   }

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

   public String getEmail() {
       return email;
   }

   public void setEmail(String email) {
       this.email = email;
   }

   public String getPassword() {
       return password;
   }

   public void setPassword(String password) {
       this.password = password;
   }

   public String getName() {
       return name;
   }

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

   public Role getRole() {
       return role;
   }

   public void setRole(Role role) {
       this.role = role;
   }

   public boolean isAdmin() {
       return Role.ADMIN.equals(role);
   }

   public boolean isUser() {
       return Role.USER.equals(role);
   }

   @Override
   public int hashCode() {
       return getId();
   }

   @Override
   public boolean equals(Object obj) {
       if (obj instanceof User) {
           User user = (User) obj;
           return user.getId() == id;
       }

       return false;
   }
}

Answer 1

此错误与 Class 未找到或未找到库有关，请尝试重新导入正确的 Hibernate 和 JPA 库。

下载：http://hibernate.org/orm/

解压缩并从文件夹 hibernate\lib\required 复制所有 jar 以实现 ORM Hibernate 的正确功能，并从 hibernate\lib\jpa 复制所有 jar 以包含 JPA。

在构建路径上导入所有 jar（导入外部 jar），完成。