Question

我有一个xhtml页面，在其中我使用存储在辅助bean中的信息。但是我需要在xhtml使用之前在bean构造中做一些操作。该操作包括从数据库中检索数据然后我使用一个方法进行此操作，并将其称为search并使用@PostConstruct注释它。但当我打电话给我的xhtml页面时，我得到以下例外：

type Exception report

message An error occurred performing resource injection on managed bean MemberSearchControler

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: An error occurred performing resource injection on managed bean MemberSearchControler
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:659)
root cause

com.sun.faces.mgbean.ManagedBeanCreationException: An error occurred performing resource injection on managed bean MemberSearchControler
    com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:227)
    com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103)
    com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
    com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
    com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
    com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
    com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
    com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
    org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:69)
    org.apache.el.parser.AstValue.getValue(AstValue.java:112)
    org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
    com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
    javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
    javax.faces.component.UIData.getValue(UIData.java:732)
    javax.faces.component.UIData.getDataModel(UIData.java:1811)
    javax.faces.component.UIData.setRowIndexWithoutRowStatePreserved(UIData.java:484)
    javax.faces.component.UIData.setRowIndex(UIData.java:473)
    com.sun.faces.renderkit.html_basic.TableRenderer.encodeBegin(TableRenderer.java:82)
    javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
    javax.faces.component.UIData.encodeBegin(UIData.java:1133)
    javax.faces.component.UIComponent.encodeAll(UIComponent.java:1894)
    javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
    javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
    javax.faces.component.UIComponent.encodeAll(UIComponent.java:1896)
    javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)
    javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)
    com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:451)
    com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
    javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
    org.apache.myfaces.tomahawk.application.ResourceViewHandlerWrapper.renderView(ResourceViewHandlerWrapper.java:169)
    com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
    com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
root cause

com.sun.faces.spi.InjectionProviderException: java.lang.IllegalArgumentException: Invalid PostConstruct annotation


com.sun.faces.vendor.Tomcat6InjectionProvider.invokePostConstruct(Tomcat6InjectionProvider.java:120)    com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:221)  com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103)    com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)    com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)   com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)  com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)     com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)  com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)   org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:69)  org.apache.el.parser.AstValue.getValue(AstValue.java:112)   org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)    com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)  javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)  javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)  javax.faces.component.UIData.getValue(UIData.java:732)  javax.faces.component.UIData.getDataModel(UIData.java:1811)     javax.faces.component.UIData.setRowIndexWithoutRowStatePreserved(UIData.java:484)   javax.faces.component.UIData.setRowIndex(UIData.java:473)   com.sun.faces.renderkit.html_basic.TableRenderer.encodeBegin(TableRenderer.java:82)     javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)     javax.faces.component.UIData.encodeBegin(UIData.java:1133)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1894)  javax.faces.render.Renderer.encodeChildren(Renderer.java:176)   javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1896)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)  com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:451)     com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)   javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)  org.apache.myfaces.tomahawk.application.ResourceViewHandlerWrapper.renderView(ResourceViewHandlerWrapper.java:169)  com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)   com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)   com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)    javax.faces.webapp.FacesServlet.service(FacesServlet.java:647) root cause

java.lang.IllegalArgumentException: Invalid PostConstruct annotation    org.apache.catalina.util.DefaultAnnotationProcessor.postConstruct(DefaultAnnotationProcessor.java:85)   com.sun.faces.vendor.Tomcat6InjectionProvider.invokePostConstruct(Tomcat6InjectionProvider.java:118)    com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:221)  com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103)    com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)    com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)   com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)  com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)     com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)  com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)   org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:69)  org.apache.el.parser.AstValue.getValue(AstValue.java:112)   org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)    com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)  javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)  javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)  javax.faces.component.UIData.getValue(UIData.java:732)  javax.faces.component.UIData.getDataModel(UIData.java:1811)     javax.faces.component.UIData.setRowIndexWithoutRowStatePreserved(UIData.java:484)   javax.faces.component.UIData.setRowIndex(UIData.java:473)   com.sun.faces.renderkit.html_basic.TableRenderer.encodeBegin(TableRenderer.java:82)     javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)     javax.faces.component.UIData.encodeBegin(UIData.java:1133)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1894)  javax.faces.render.Renderer.encodeChildren(Renderer.java:176)   javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1896)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)  javax.faces.component.UIComponent.encodeAll(UIComponent.java:1899)  com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:451)     com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)   javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)  org.apache.myfaces.tomahawk.application.ResourceViewHandlerWrapper.renderView(ResourceViewHandlerWrapper.java:169)  com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)   com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)   com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)    javax.faces.webapp.FacesServlet.service(FacesServlet.java:647) note The full stack trace of the root cause is available in the Apache Tomcat/6.0.37 logs.

这是我的支持bean：

ManagedBean(name="MemberSearchControler")
@SessionScoped
public class MemebrSearchControl {

    public MemebrSearchControl(){
        System.out.println("Test");
    }

    private String text;
    private List<Member> members;

    //For Create CheckBox
    private int[] membersId;
    public int[] getMembersId() {
        return membersId;
    }

    //For get Selected Member Id
    private int[] selectedMembers;
    public void setSelectedMember(int[] ids) {
        selectedMembers=ids;
    }   

    public List<Member> getMembers() {
        return members;
    }
    public int getMembersCount() {
        return membersCount;
    }

    private int membersCount;

    public String getText() {
        return text;
    }
    public void setText(String text) {
        this.text = text;
    }


    @PostConstruct
    public String search() throws DaoImplNotFoundException, DataSourceException{
        MemberDao dao=(MemberDao) Factory.getDao(ConfigReader.getConfig().getProperty("dao.member"));
        members=dao.list(1, 10);
        membersId=new int[members.size()];
        for(int i=0;i<members.size();i++)
            membersId[i]=members.get(i).getId();
        return "member";
    }


}

Answer 1

阅读the documentation总是有帮助的，更具体地说是这些行（强调我的）：

应用PostConstruct注释的方法必须满足以下所有条件 - - 除了EJB拦截器之外，方法绝不能有任何参数，在这种情况下它需要一个InvocationC ontext EJB规范定义的对象。 - 方法的返回类型必须无效。 - 该方法不得抛出已检查的异常 ...（其他要求已省略）

所以，至少不满足返回类型要求（我们不知道您的异常是否被检查，所以我删除了它们，但是在这种情况下你需要处理方法中的异常）。

总而言之，用

替换你的方法

@PostConstruct
public void search() {
    MemberDao dao=(MemberDao) Factory.getDao(ConfigReader.getConfig().getProperty("dao.member"));
    members=dao.list(1, 10);
    membersId=new int[members.size()];
    for(int i=0;i<members.size();i++)
        membersId[i]=members.get(i).getId();
}

根据您的评论，您的例外类是经过检查的例外情况。因此，您必须在方法中引入try-catch块，或者让您的异常从RuntimeException继承。如果您选择以前的方式，则可以重新抛出未经检查的异常，例如IllegalStateException，或者，例如，发送重定向，以防它为时已晚：

@PostConstruct
public void search() {
    try {
        MemberDao dao=(MemberDao) Factory.getDao(ConfigReader.getConfig().getProperty("dao.member"));
        members=dao.list(1, 10);
        membersId=new int[members.size()];
        for(int i=0;i<members.size();i++)
            membersId[i]=members.get(i).getId();
    } catch(DaoImplNotFoundException dinf) {
        //option one
        throw new IllegalStateException("Something went wrong.");
        //option two
        FacesContext.getCurrentInstance().getExternalContext().redirect("/error.xhtml");
    } //other exception types
}

PostConstruct注释无效

1 个答案: