处理请求时发生异常：null：DAO bean 中的 java.lang.NullPointerException

问题描述 投票：0回答：2

我的数据库使用的 

create()
和 
insert()
方法有问题。我使用 Struts、Hibernate 和 MySQL 作为数据库。

我已经尝试解决这个问题很长时间了，但没有任何结果。

我的班级模特：

package clowzer.charaf.model;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;


@Entity 
@Table (name="JOUEUR")
public class Joueur{

@Id 
@Column(name="id")
private Integer id;

@Column(name="nom" )
private String nom;

@Column(name="prenom")
private String prenom;

@Column(name="pseudo")
private String pseudo;

@Column(name="login")
private String login;

@Column(name="image")
private String image;

@Column(name = "datecreationcompte")
@Temporal(TemporalType.TIMESTAMP)
private Date datecreationcompte;

@Column(name="motdepasse")
private String motdepasse;

@Column(name="statut")
private Integer statut;

@Column(name="xx")
private String xx;














public Integer getId() {
    return id;
}

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

public String getNom() {
    return nom;
}

public void setNom(String nom) {
    this.nom = nom;
}

public String getPrenom() {
    return prenom;
}

public void setPrenom(String prenom) {
    this.prenom = prenom;
}

public String getPseudo() {
    return pseudo;
}

public void setPseudo(String pseudo) {
    this.pseudo = pseudo;
}

public String getLogin() {
    return login;
}

public void setLogin(String login) {
    this.login = login;
}

public String getImage() {
    return image;
}

public void setImage(String image) {
    this.image = image;
}

public Date getDatecreationcompte() {
    return datecreationcompte;
}

public void setDatecreationcompte(Date datecreationcompte) {
    this.datecreationcompte = datecreationcompte;
}

public String getMotdepasse() {
    return motdepasse;
}

public void setMotdepasse(String motdepasse) {
    this.motdepasse = motdepasse;
}

public Integer getStatut() {
    return statut;
}

public void setStatut(Integer statut) {
    this.statut = statut;
}

public String getXx() {
    return xx;
}

public void setXx(String xx) {
    this.xx = xx;
}

}

我的 DAO 课程：

package clowzer.charaf.dao.joueur;


import java.util.List;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import clowzer.charaf.model.Joueur;

public class JoueurDaoImpl implements JoueurDAO {

@Autowired 
SessionFactory sessionFactory;

public void setSessionFactory(SessionFactory sessionFactory) {
    this.sessionFactory = sessionFactory;
}


@Override
public void ajouterjoueur(Joueur joueur) {
    sessionFactory.getCurrentSession().saveOrUpdate(joueur);        
}

我的豆子：

<?xml  version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
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/context http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
    http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">


<context:annotation-config />


<!-- CONNEXION JDBC -->
<bean id="propertyConfigurer"
    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
    p:location="/WEB-INF/jdbc.properties" />

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close" p:driverClassName="com.mysql.jdbc.Driver"
    p:url="jdbc:mysql://localhost/mybase" p:username="root" p:password="root" />

<!-- FIN CONNEXION JDBC -->

<bean id="sessionFactory"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation">
        <value>classpath:hibernate.cfg.xml</value>
    </property>
    <property name="hibernateProperties">
        <props>
             <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>  
            <prop key="hibernate.show_sql">false</prop>
        </props>
    </property>
</bean>


<bean id="joueurDao" class="clowzer.charaf.dao.joueur.JoueurDaoImpl"></bean>
<bean id="joueurManager"    class="clowzer.charaf.service.joueur.JoueurManagerImpl"></bean>


<bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>


                                            
<tx:annotation-driven  transaction-manager="transactionManager" />

错误消息：

2016-12-02 09:57:30,204 ERROR [org.apache.struts2.dispatcher.Dispatcher] - <Exception occurred during processing request: null>
java.lang.NullPointerException
at    clowzer.charaf.dao.joueur.JoueurDaoImpl.ajouterjoueur(JoueurDaoImpl.java:57)
at clowzer.charaf.controleur.joueur.Joueur.ajouterjoueur(Joueur.java:106)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:446)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:285)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:544)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
mysql spring hibernate struts2 integration
2个回答
0
投票

就堆栈跟踪而言，看来您的 

sessionFactory.getCurrentSession().saveOrUpdate(joueur);

有问题，您的 

getCurrentSession()
为空或您的实体为空。

您可能需要检查Web应用程序的启动日志中是否出现任何异常，这个问题很可能与Hibernate初始化和数据库连接有关。

0
投票

如何创建 DAO bean？配置没有必需的属性引用。它不能在不知道 beans 配置的情况下自动装配。

<property name="sessionFactory" ref="sessionFactory" />

Struts-Spring 集成可通过插件实现。从日志中可以看出，您没有使用 Spring 和 Struts 2 集成。 Struts 和 Spring 通过 Spring 插件 集成。 Struts 默认情况下按名称自动装配。因此，您可以将 DAO 或服务直接注入到操作 bean 中。您不需要为操作控制器编写配置，但对于其他 bean，您必须这样做。

这是如何运作的

Spring 插件通过覆盖 Struts 

ObjectFactory
来增强核心框架对象的创建。当要创建一个对象时，它使用Struts配置中的class属性来对应Spring配置中的id属性。如果没有找到，该类将尝试像往常一样创建，然后由 Spring 自动装配。对于 Actions，Spring 2 的 bean 范围功能可用于将 
Action
实例范围限定为会话、应用程序或自定义范围，从而提供高于默认每个请求范围的高级自定义。

要使用插件，只需将其添加到类路径中即可。

要启用 Spring 集成，只需在您的应用程序中包含 

struts2-spring-plugin-x-x-x.jar
即可。

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