Java Hibernate查询NullPointerException（@ManyToMany）
我还在接受教育，请耐心点。：-） 我有一个类Teilnehmer.JavaJava Hibernate查询NullPointerException（@ManyToMany）,java,hibernate,ejb,many-to-many,hql,Java,Hibernate,Ejb,Many To Many,Hql,我还在接受教育，请耐心点。：-） 我有一个类Teilnehmer.Java @Entity @Table(name = "Teilnehmer") public class Teilnehmer implements java.io.Serializable { private Integer id; private String nachname; private String vorname; private String email; @Type(type="org.domain.tkt.
@Entity
@Table(name = "Teilnehmer")
public class Teilnehmer implements java.io.Serializable {
private Integer id;
private String nachname;
private String vorname;
private String email;
@Type(type="org.domain.tkt.entity.EnumUserType",parameters={@org.hibernate.annotations.Parameter(name="type",value="org.domain.tkt.entity.Gender")})
private Gender gender;
private List<Team> teams = new ArrayList<Team>();;
private String userName;
private Rolle rolle;
public Teilnehmer() {
}
@Column(name = "user_name",unique = true,length = 16)
@Length(min = 4,max = 16)
@Pattern(regex = "^[a-zA-Z\\d_]{4,12}$",message = "{invalid_screen_name}")
@UserPrincipal
public String getUserName() {
return this.userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
17:33:42,562 INFO [STDOUT] Hibernate:
select
teilnehmer0_.id as id7_,
teilnehmer0_.user_name as user2_7_,
teilnehmer0_.email as email7_,
teilnehmer0_.nachname as nachname7_,
teilnehmer0_.vorname as vorname7_,
teilnehmer0_.rolle_rolle_id as rolle14_7_,
teilnehmer0_.gender as gender7_,
teilnehmer0_.photo as photo7_,
teilnehmer0_.created_on as created8_7_,
teilnehmer0_.abteilung_id as abteilung15_7_,
teilnehmer0_.password as password7_,
teilnehmer0_.activation_key as activation10_7_,
teilnehmer0_.photo_image_type as photo11_7_,
teilnehmer0_.temporary_password as temporary12_7_,
teilnehmer0_.active as active7_
from
Teilnehmer teilnehmer0_
where
teilnehmer0_.user_name=?
17:33:42,595 INFO [STDOUT] Hibernate:
select
rolle0_.rolle_id as rolle1_11_0_,
rolle0_.name as name11_0_,
rolle0_.beschreibung as beschrei3_11_0_
from
rolle rolle0_
where
rolle0_.rolle_id=?
17:33:42,624 FATAL [application] java.lang.NullPointerException
javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:91)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:91)
at javax.faces.component.UICommand.broadcast(UICommand.java:383)
at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:329)
at org.ajax4jsf.component.AjaxViewRoot.broadcastEventsForPhase(AjaxViewRoot.java:304)
at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:261)
at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:474)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.domain.tkt.entity.IE9CompatablityFilter.doFilter(IE9CompatablityFilter.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:206)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:580)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
@实体
@表（name=“rolle”）
公共类Rolle实现java.io.Serializable{
静态最终长serialVersionUID=-2631452282682699312L；
私人长罗莱德；
私人串beschreibung；
私有字符串名称；
私人电视台；
公共无效设置项（设置项）{
this.teilnehmer=teilnehmer；
}
@OneToMany（mappedBy=“rolle”）
公共集getTeilnehmer（）
{
归还这个。泰尔内默；
}
@身份证
@GeneratedValue（策略=GenerationType.AUTO）
@列（name=“rolle\u id”）
公共长getRoleId（）{
返回此.roleId；
}
公共void setRoleId（长roleId）{
this.roleId=roleId；
}
@列（name=“beschreibung”，null=false，长度=90）
@NotNull
@长度（最大值=90）
公共字符串getBeschreibung（）{
把这个还给我；
}
公共void setbeschribung（字符串描述）{
这个.beschreibung=描述；
}
@列（name=“name”，unique=true，nullable=false，length=30）
@NotNull
@长度（最小值=4，最大值=30）
@罗兰胺
@模式（regex=“^[a-zA-Z\\d\]{4,12}$”，message=“{invalid_role_name}”）
公共字符串getName（）{
返回此.name；
}
公共void集合名（字符串名）{
this.name=name；
}
}您可以使用
getResultList（）.get（0）getSingleResult（）byUserName（） protected Teilnehmer byUserName(String userName) {
Teilnehmer t=null;
try {
Query q = entityManager.createQuery("select teilnehmer from "+Teilnehmer.class.getName() +" as teilnehmer inner join teilnehmer.userName as name where name like :userName");
q.setParameter("userName", userName);
t=(Teilnehmer)q.getResultList().get(0);
} catch (javax.persistence.NoResultException nre) {
}
return t;
}
谢谢你的要求！但这毫无帮助。我已经用您提供的byUserName（）方法尝试过了，但是仍然有一个NullPointer异常。好吧，我的错。Authenticator.java中存在问题。。。但是现在Hibernate有一个异常：
是由org.Hibernate.hql.ast.HqlSqlWalker.createFromJoinElement（HqlSqlWalker.java:310）org.Hibernate.hql.antlr.HqlSqlBaseWalker.joinElement（HqlSqlBaseWalker.java:3275）org.Hibernate.hql.hql.antlr.hqlsbasewalker.fromElement（hqlsbasewalker.java:3067）上的java.NullPointerException引起的“从teilnehmer中选择teilnehmer作为teilnehmer内部连接teilnehmer.userName作为名称，其中名称类似于：userName”17:33:42,562 INFO [STDOUT] Hibernate:
select
teilnehmer0_.id as id7_,
teilnehmer0_.user_name as user2_7_,
teilnehmer0_.email as email7_,
teilnehmer0_.nachname as nachname7_,
teilnehmer0_.vorname as vorname7_,
teilnehmer0_.rolle_rolle_id as rolle14_7_,
teilnehmer0_.gender as gender7_,
teilnehmer0_.photo as photo7_,
teilnehmer0_.created_on as created8_7_,
teilnehmer0_.abteilung_id as abteilung15_7_,
teilnehmer0_.password as password7_,
teilnehmer0_.activation_key as activation10_7_,
teilnehmer0_.photo_image_type as photo11_7_,
teilnehmer0_.temporary_password as temporary12_7_,
teilnehmer0_.active as active7_
from
Teilnehmer teilnehmer0_
where
teilnehmer0_.user_name=?
17:33:42,595 INFO [STDOUT] Hibernate:
select
rolle0_.rolle_id as rolle1_11_0_,
rolle0_.name as name11_0_,
rolle0_.beschreibung as beschrei3_11_0_
from
rolle rolle0_
where
rolle0_.rolle_id=?
17:33:42,624 FATAL [application] java.lang.NullPointerException
javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:91)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:91)
at javax.faces.component.UICommand.broadcast(UICommand.java:383)
at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:329)
at org.ajax4jsf.component.AjaxViewRoot.broadcastEventsForPhase(AjaxViewRoot.java:304)
at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:261)
at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:474)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.domain.tkt.entity.IE9CompatablityFilter.doFilter(IE9CompatablityFilter.java:23)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:206)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:580)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
@Entity
@Table(name="rolle")
public class Rolle implements java.io.Serializable {
static final long serialVersionUID=-2631452282682699312L;
private Long roleId;
private String beschreibung;
private String name;
private Set<Teilnehmer> teilnehmer;
public void setTeilnehmer(Set<Teilnehmer> teilnehmer) {
this.teilnehmer = teilnehmer;
}
@OneToMany(mappedBy="rolle")
public Set<Teilnehmer> getTeilnehmer()
{
return this.teilnehmer;
}
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="rolle_id")
public Long getRoleId() {
return this.roleId;
}
public void setRoleId(Long roleId) {
this.roleId=roleId;
}
@Column(name="beschreibung",nullable=false,length=90)
@NotNull
@Length(max=90)
public String getBeschreibung() {
return this.beschreibung;
}
public void setBeschreibung(String description) {
this.beschreibung=description;
}
@Column(name="name",unique=true,nullable=false,length=30)
@NotNull
@Length(min=4,max=30)
@RoleName
@Pattern(regex="^[a-zA-Z\\d_]{4,12}$",message="{invalid_role_name}")
public String getName() {
return this.name;
}
public void setName(String name) {
this.name=name;
}
protected Teilnehmer byUserName(String userName) {
Teilnehmer t=null;
try {
Query q = entityManager.createQuery("select teilnehmer from "+Teilnehmer.class.getName() +" as teilnehmer inner join teilnehmer.userName as name where name like :userName");
q.setParameter("userName", userName);
t=(Teilnehmer)q.getResultList().get(0);
} catch (javax.persistence.NoResultException nre) {
}
return t;
}