Question

我正在使用JPA，EJB和JSP编写我的第一个Java EE应用程序。到目前为止，我还没有使用除Tomcat服务器和JSP页面之外的其他程序来编写一些简单的Web应用程序。因为我正在编写一个非常大的项目，所以我决定开发一个带有EJB和JPA的Java企业应用程序，用于模型（使用自动代码生成持久性）和Payara Server。我知道使用自动代码生成并不是一种很好的做法，但我是四肢瘫痪的，我需要为我写的东西... 不幸的是，EJB的第一个操作返回错误，我无法继续。

这是服务器日志：

Caused by: java.lang.IllegalArgumentException: NamedQuery of name: findByName not found.
    at org.eclipse.persistence.internal.jpa.QueryImpl.getDatabaseQueryInternal(QueryImpl.java:355)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.createNamedQuery(EntityManagerImpl.java:1135)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.createNamedQuery(EntityManagerWrapper.java:522)
    at model.session.BrandFacade.getBrandByName(BrandFacade.java:41)
    at model.session.BrandFacade.create(BrandFacade.java:52)
    at model.session.BrandFacade.create(BrandFacade.java:61)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
    at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    ... 34 more

这是BrandCrudController ...调用.create方法生成错误：

package controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.entities.Brand;
import model.exceptions.DuplicateException;
import model.session.localInterfaces.BrandFacadeLocal;

public class BrandCrudController extends HttpServlet {

    @EJB
    private BrandFacadeLocal brandFacade;

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");


        try {
            brandFacade.create("name");
        } catch (DuplicateException ex) {
            Logger.getLogger(BrandCrudController.class.getName()).log(Level.SEVERE, null, ex);
        } //*/


        try (PrintWriter out = response.getWriter()) {
            /* TODO output your page here. You may use following sample code. */
            out.println("<!DOCTYPE html>");
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet NewServlet</title>");            
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>brand creato </h1>");
            out.println("</body>");
            out.println("</html>");
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}

这是BrandFacade.java

package model.session;

import model.session.localInterfaces.BrandFacadeLocal;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import model.entities.Brand;
import model.exceptions.DuplicateException;


@Stateless
public class BrandFacade extends AbstractFacade<Brand> implements BrandFacadeLocal {

    @PersistenceContext(unitName = "MyWheelEE-ejbPU")
    private EntityManager em;

    @Override
    protected EntityManager getEntityManager() {
        return em;
    }

    public BrandFacade() {
        super(Brand.class);
    }

    @Override
    public Brand getBrandByName(String name) {
        Brand b = null;
        try {
            b = (Brand) em.createNamedQuery("findByName")
                .setParameter("name", name)
                .getSingleResult();
        } catch (NoResultException e) {
            return null;
        }
        return b;
    }

    @Override
    public void create(String name) throws DuplicateException {
        if (getBrandByName(name)!= null)
            throw new DuplicateException("this name  already exists");
        Brand b =new Brand(0, name);
        em.persist(b);       
    }

    @Override
    public void create(Brand brand) {
        try {
            create(brand.getName());
        } catch (DuplicateException ex) {
            Logger.getLogger(BrandFacade.class.getName()).log(Level.SEVERE, null, ex);
        }
    }


}

这是Brand.java实体

package model.entities;

import java.io.Serializable;
import java.util.List;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;

/**
 *
 * @author Marco Bellaiuto
 */
@Entity
@Table(name = "brand")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Brand.findAll", query = "SELECT b FROM Brand b"),
    @NamedQuery(name = "Brand.findByOid", query = "SELECT b FROM Brand b WHERE b.oid = :oid"),
    @NamedQuery(name = "Brand.findByName", query = "SELECT b FROM Brand b WHERE b.name = :name")})
public class Brand implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "oid")
    private Integer oid;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 15)
    @Column(name = "name")
    private String name;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "brandOid")
    private List<Wheelchair> wheelchairList;

    public Brand() {
    }

    public Brand(Integer oid) {
        this.oid = oid;
    }

    public Brand(Integer oid, String name) {
        this.oid = oid;
        this.name = name;
    }

    public Integer getOid() {
        return oid;
    }

    public void setOid(Integer oid) {
        this.oid = oid;
    }

    public String getName() {
        return name;
    }

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

    @XmlTransient
    public List<Wheelchair> getWheelchairList() {
        return wheelchairList;
    }

    public void setWheelchairList(List<Wheelchair> wheelchairList) {
        this.wheelchairList = wheelchairList;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (oid != null ? oid.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Brand)) {
            return false;
        }
        Brand other = (Brand) object;
        if ((this.oid == null && other.oid != null) || (this.oid != null && !this.oid.equals(other.oid))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "model.entities.Brand[ oid=" + oid + " ]";
    }

}

Answer 1

您的错误就在这里，在您的堆栈跟踪中：

Caused by: java.lang.IllegalArgumentException: NamedQuery of name: findByName not found.

您有一个命名查询"Brand.findByName"，但您的代码正在调用"findByName"并且不存在。你的门面应该致电Brand.findByName

java.lang.IllegalArgumentException：名称的NamedQuery：找不到findByName

1 个答案: