我有两个网页，每个网页都有一个bean支持，以及在Glassfish 4.0服务器上运行的多个DAO。第一页是登录页面 - 一切正常，我可以访问注入的对象。
然而，在第二页上，每当我尝试访问其中一个注入的对象时，我都会得到一个nullpointer-exception。
这是我的（工作）登录页面：
@ViewScoped
@Named
public class indexController implements Serializable {
private static final Logger log = Logger.getLogger(indexController.class.getName());
private String passwort, growlMsg;
@Inject
Manager manager;
@Inject
PersonalDAO personalDAO;
public indexController() {
}
public String login() {
System.out.println("------------------LOGIN-----------------------\n"
+ "Werk: " + getWerk() + "\n"
+ "Mandant: " + getMandant() + "\n"
+ "Personalnr:" + getPersnr() + "\n"
+ "Passwort: " + passwort + "\n"
+ "----------------------------------------------");
if (isValidUser()) {
manager.setUserVerified(true);
return "main";
} else {
FacesContext ctx = FacesContext.getCurrentInstance();
ctx.addMessage(null, new FacesMessage("Login failed.", "Please verify your login credentials."));
return "index";
}
}
//TODO: Implement hashing and salting
private boolean isValidUser() {
List<Personal> pers = personalDAO.find(getPersnr());
if (pers.isEmpty()) {
return false;
}
Personal personal = pers.get(0);
if (personal.getWerk().getId() != getWerk()) {
return false;
}
if (personal.getMandant().getId() != getMandant()) {
return false;
}
if (!personal.getPasswort().equals(passwort)) {
return false;
}
return true;
}
private boolean isInteger(String n) {
try {
Integer.parseInt(n);
} catch (NumberFormatException ex) {
return false;
}
return true;
}
public int getMandant() {
return manager.getMandant();
}
public void setMandant(int mandant) {
manager.setMandant(mandant);
}
public int getWerk() {
return manager.getWerk();
}
public void setWerk(int werk) {
manager.setWerk(werk);
}
public int getPersnr() {
return manager.getPersnr();
}
public void setPersnr(int persnr) {
manager.setPersnr(persnr);
}
public String getPasswort() {
return passwort;
}
public void setPasswort(String passwort) {
this.passwort = passwort;
}
public String getGrowlMsg() {
return growlMsg;
}
public void setGrowlMsg(String growlMsg) {
this.growlMsg = growlMsg;
}
}
这是我遇到问题的bean：
@RequestScoped
@Named
public class mainController implements Serializable {
private List<Abwesenheit> abwesenheit;
private List<Personal> personal;
@Inject
Manager manager;
@Inject
PersonalDAO personalDAO;
@Inject
AbwesenheitDAO abwesenheitDAO;
public mainController() {
System.out.println("-----MAINCONTROLLER CALLED-----");
System.out.println(manager.isUserVerified());
System.out.println("-----------------------------------");
}
public List<Abwesenheit> getAbwesenheit() {
return abwesenheit;
}
public void setAbwesenheit(List<Abwesenheit> abwesenheit) {
this.abwesenheit = abwesenheit;
}
public List<Personal> getPersonal() {
return personal;
}
public String getVerified() {
return manager.isUserVerified()?"Verified":"Not Verified";
}
}
经理班：
@SessionScoped
public class Manager implements Serializable {
//TODO: Use an enum for access-levels instead of just access/no access
private boolean userVerified = false;
int werk, mandant, persnr;
public Manager() {
}
public boolean isUserVerified() {
return userVerified;
}
public void setUserVerified(boolean userVerified) {
this.userVerified = userVerified;
}
public int getWerk() {
return werk;
}
public void setWerk(int werk) {
this.werk = werk;
}
public int getMandant() {
return mandant;
}
public void setMandant(int mandant) {
this.mandant = mandant;
}
public int getPersnr() {
return persnr;
}
public void setPersnr(int persnr) {
this.persnr = persnr;
}
}
personalDAO class：
@Stateless
public class PersonalDAO implements Serializable {
@PersistenceContext(unitName="GFOS_AwardPU")
private EntityManager entityManager;
public List<Personal> getPersonal() {
return entityManager.createNamedQuery("Personal.findAll", Personal.class).getResultList();
}
public List<Personal> find(String personalNr) {
Query query = entityManager.createNamedQuery("Personal.findByPersonalnr");
query.setParameter("personalnr", personalNr);
return query.getResultList();
}
public List<Personal> find(int personalNr) {
Query query = entityManager.createNamedQuery("Personal.findByPersonalnr");
query.setParameter("personalnr", personalNr);
return query.getResultList();
}
public List<Personal> find(String personalNr, String name, String vorname, String mandant, String werk) {
String query = "SELECT * FROM Personal WHERE 1=1";
if(personalNr != null && !personalNr.isEmpty()) {
query += " AND Personalnr="+personalNr;
}
if(name != null && !name.isEmpty()) {
query += " AND name='"+name+"'";
}
if(vorname != null && !vorname.isEmpty()) {
query += " AND vorname='"+vorname+"'";
}
if(mandant != null && !mandant.isEmpty()) {
query += " AND mandant="+mandant;
}
if(werk != null && !werk.isEmpty()) {
query += " AND werk="+werk;
}
return entityManager.createNativeQuery(query, Personal.class).getResultList();
}
}
这是Glassfish服务器日志提取，之前没有例外：
[2016-03-10T19:43:21.303+0100] [glassfish 4.0] [INFO] [] [] [tid: _ThreadID=22 _ThreadName=Thread-3] [timeMillis: 1457635401303] [levelValue: 800] [[
-----MAINCONTROLLER CALLED-----]]
[2016-03-10T19:43:21.304+0100] [glassfish 4.0] [SEVERE] [] [javax.enterprise.resource.webcontainer.jsf.application] [tid: _ThreadID=22 _ThreadName=http-listener-1(5)] [timeMillis: 1457635401304] [levelValue: 1000] [[
Error Rendering View[/main.xhtml]
java.lang.NullPointerException
at controller.mainController.<init>(mainController.java:38)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.jboss.weld.injection.ConstructorInjectionPoint.newInstance(ConstructorInjectionPoint.java:79)
at org.jboss.weld.injection.ConstructorInjectionPoint.newInstance(ConstructorInjectionPoint.java:63)
at org.jboss.weld.injection.producer.AbstractInstantiator.newInstance(AbstractInstantiator.java:29)
at org.jboss.weld.injection.producer.DefaultInstantiator.newInstance(DefaultInstantiator.java:90)
at org.jboss.weld.injection.producer.BasicInjectionTarget.produce(BasicInjectionTarget.java:86)
at org.jboss.weld.injection.producer.BeanInjectionTarget.produce(BeanInjectionTarget.java:172)
at org.jboss.weld.bean.ManagedBean.create(ManagedBean.java:157)
at org.jboss.weld.context.unbound.DependentContextImpl.get(DependentContextImpl.java:69)
at org.jboss.weld.manager.BeanManagerImpl.getReference(BeanManagerImpl.java:716)
at org.jboss.weld.el.AbstractWeldELResolver.lookup(AbstractWeldELResolver.java:133)
at org.jboss.weld.el.AbstractWeldELResolver.getValue(AbstractWeldELResolver.java:96)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:116)
at com.sun.el.parser.AstValue.getBase(AstValue.java:151)
at com.sun.el.parser.AstValue.getValue(AstValue.java:200)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226)
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIOutput.getValue(UIOutput.java:174)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355)
at com.sun.faces.renderkit.html_basic.LabelRenderer.encodeBegin(LabelRenderer.java:120)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:869)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:443)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
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:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Unknown Source)
]]
[2016-03-10T19:43:21.358+0100] [glassfish 4.0] [INFO] [] [] [tid: _ThreadID=22 _ThreadName=Thread-3] [timeMillis: 1457635401358] [levelValue: 800] [[
-----MAINCONTROLLER CALLED-----]]
[2016-03-10T19:43:21.375+0100] [glassfish 4.0] [FATAL] [jsf.context.exception.handler.log] [javax.enterprise.resource.webcontainer.jsf.context] [tid: _ThreadID=22 _ThreadName=http-listener-1(5)] [timeMillis: 1457635401375] [levelValue: 1100] [[
JSF1073: java.lang.NullPointerException erfasst w?hrend Verarbeitung von RENDER_RESPONSE 6 : UIComponent-ClientId=, Message=null]]
[2016-03-10T19:43:21.376+0100] [glassfish 4.0] [FATAL] [] [javax.enterprise.resource.webcontainer.jsf.context] [tid: _ThreadID=22 _ThreadName=http-listener-1(5)] [timeMillis: 1457635401376] [levelValue: 1100] [[
java.lang.NullPointerException
at controller.mainController.<init>(mainController.java:38)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.jboss.weld.injection.ConstructorInjectionPoint.newInstance(ConstructorInjectionPoint.java:79)
at org.jboss.weld.injection.ConstructorInjectionPoint.newInstance(ConstructorInjectionPoint.java:63)
at org.jboss.weld.injection.producer.AbstractInstantiator.newInstance(AbstractInstantiator.java:29)
at org.jboss.weld.injection.producer.DefaultInstantiator.newInstance(DefaultInstantiator.java:90)
at org.jboss.weld.injection.producer.BasicInjectionTarget.produce(BasicInjectionTarget.java:86)
at org.jboss.weld.injection.producer.BeanInjectionTarget.produce(BeanInjectionTarget.java:172)
at org.jboss.weld.bean.ManagedBean.create(ManagedBean.java:157)
at org.jboss.weld.context.unbound.DependentContextImpl.get(DependentContextImpl.java:69)
at org.jboss.weld.manager.BeanManagerImpl.getReference(BeanManagerImpl.java:716)
at org.jboss.weld.el.AbstractWeldELResolver.lookup(AbstractWeldELResolver.java:133)
at org.jboss.weld.el.AbstractWeldELResolver.getValue(AbstractWeldELResolver.java:96)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:116)
at com.sun.el.parser.AstValue.getBase(AstValue.java:151)
at com.sun.el.parser.AstValue.getValue(AstValue.java:200)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226)
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIOutput.getValue(UIOutput.java:174)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355)
at com.sun.faces.renderkit.html_basic.LabelRenderer.encodeBegin(LabelRenderer.java:120)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:869)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:443)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
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:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Unknown Source)
]]
为什么它不能在mainController类中运行？我试过改变这两个课程的范围，但这没有帮助。 Netbeans没有显示任何错误。我也试过通过Netbeans或手动启动Glassfish。我尝试的最后一件事是改变
的导入import javax.faces.bean.RequestScoped
（以及经理类的SessionScoped）
import javax.enterprise.context.RequestScoped
但它没有解决我的问题。
答案 0 :(得分：3)
而不是构造函数
public mainController() {
System.out.println("-----MAINCONTROLLER CALLED-----");
System.out.println(manager.isUserVerified());
System.out.println("-----------------------------------");
}
使用带注释@PostConstruct的方法。
@PostConstruct
private void init() {
System.out.println("-----MAINCONTROLLER INITIALIZED-----");
System.out.println(manager.isUserVerified());
System.out.println("-----------------------------------");
}
依赖关系尚未在构造函数中注入，可以在创建对象后访问它们。