java - 在我的 Spring Hibernate 项目上获取 InvokingTargetException

Question

Here is the table of data

我已经使用 mySQL 中的数据库创建了一个简单的 hibernate/spring 和 CRUD。除了我的编辑功能之外，一切正常。它说这个错误。

root cause

org.springframework.beans.InvalidPropertyException: Invalid property 'id' of bean class [org.jjm.test.model.Phone_$$_jvst33c_0]: Getter for property 'id' threw exception; nested exception is java.lang.reflect.InvocationTargetException
    org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:704)
    org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:610)
    org.springframework.validation.AbstractPropertyBindingResult.getActualFieldValue(AbstractPropertyBindingResult.java:99)
    org.springframework.validation.AbstractBindingResult.getFieldValue(AbstractBindingResult.java:229)
    org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:120)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getBindStatus(AbstractDataBoundFormElementTag.java:168)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getPropertyPath(AbstractDataBoundFormElementTag.java:188)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getName(AbstractDataBoundFormElementTag.java:154)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.autogenerateId(AbstractDataBoundFormElementTag.java:141)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.resolveId(AbstractDataBoundFormElementTag.java:132)
    org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.writeDefaultAttributes(AbstractDataBoundFormElementTag.java:116)
    org.springframework.web.servlet.tags.form.AbstractHtmlElementTag.writeDefaultAttributes(AbstractHtmlElementTag.java:422)
    org.springframework.web.servlet.tags.form.HiddenInputTag.writeTagContent(HiddenInputTag.java:79)
    org.springframework.web.servlet.tags.form.AbstractFormTag.doStartTagInternal(AbstractFormTag.java:84)
    org.springframework.web.servlet.tags.RequestContextAwareTag.doStartTag(RequestContextAwareTag.java:80)
    org.apache.jsp.WEB_002dINF.views.phoneDetails_jsp._jspx_meth_form_005fhidden_005f0(phoneDetails_jsp.java:322)
    org.apache.jsp.WEB_002dINF.views.phoneDetails_jsp._jspx_meth_form_005fform_005f0(phoneDetails_jsp.java:231)
    org.apache.jsp.WEB_002dINF.views.phoneDetails_jsp._jspService(phoneDetails_jsp.java:175)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
    org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
    org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1244)
    org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1027)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

它说错误与我的 ID 相关，但我在代码中看不到错误。

package org.jjm.test.model;

import javax.persistence.Column;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.GenerationType;  
import javax.persistence.Id;  
import javax.persistence.Table;  
/* 
 * This is the model class and it corresponds to Phone table in the database 
 */  
@Entity
@Table(name="PHONE")
public class Phone {

     @Id  
     @Column(name="id")  
     @GeneratedValue(strategy=GenerationType.IDENTITY)  
     int id;  

    @Column(name="phoneName")
    String phoneName;

    @Column(name="make")
    String make;

    @Column(name="price")
    double price;

    @Column(name="storage")
    String storage;

    @Column(name="camera")
    String camera;


    public Phone() {
        super();
    }


    public Phone(int i, String phoneName, String make, double price, String storage, String camera) {
        super();
        this.id = i;  
        this.phoneName = phoneName;
        this.make = make;
        this.price = price;
        this.storage = storage;
        this.camera = camera;
    }

    public int getId() {
        return id;
    }


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


    public String getPhoneName() {
        return phoneName;
    }


    public void setPhoneName(String phoneName) {
        this.phoneName = phoneName;
    }


    public String getMake() {
        return make;
    }


    public void setMake(String make) {
        this.make = make;
    }


    public double getPrice() {
        return price;
    }


    public void setPrice(double price) {
        this.price = price;
    }


    public String getStorage() {
        return storage;
    }


    public void setStorage(String storage) {
        this.storage = storage;
    }


    public String getCamera() {
        return camera;
    }


    public void setCamera(String camera) {
        this.camera = camera;
    }

}

这就是我显示数据的地方

<table>  
        <tr>  
            <th colspan="2">Add Phone</th>  
        </tr>  
        <tr>  
        <form:hidden path="id" />  
          <td><form:label path="phoneName">Phone Name:</form:label></td>  
          <td><form:input path="phoneName" size="30" maxlength="30"></form:input></td>  
        </tr>  
        <tr>  
                <td><form:label path="make">Make:</form:label></td>  
          <td><form:input path="make" size="30" maxlength="30"></form:input></td>  
        </tr>
        <tr>  
                <td><form:label path="price">Price:</form:label></td>  
          <td><form:input path="price" size="30" maxlength="30"></form:input></td>  
        </tr>  
        <tr>  
                <td><form:label path="storage">Storage:</form:label></td>  
          <td><form:input path="storage" size="30" maxlength="30"></form:input></td>  
        </tr>  
        <tr>  
                <td><form:label path="camera">Camera:</form:label></td>  
          <td><form:input path="camera" size="30" maxlength="30"></form:input></td>  
        </tr>    
        <tr>  
            <td colspan="2"><input type="submit"  
                class="blue-button" /></td>  
        </tr>  
    </table>   

Answer 1

实体ID必须可为空，将其更改为

 @Id  
 @Column(name="id")  
 @GeneratedValue(strategy=GenerationType.IDENTITY)  
 Integer id;

这是为什么呢？在插入新实体的过程中，ID 必须为 null，以便让数据库决定它的实际值。如果您说 0 甚至 162，它可能已经在数据库中使用。