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我有一个 xhtml 页面，其中我使用存储在支持 bean 中的信息。但我需要在 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。
然后我为此操作使用了一个方法，并将其称为search并使用@PostConstruct 对其进行了注释。但是当我调用我的 xhtml 页面时，我得到以下异常： 

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.

这是我的支持豆： 

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";
    }


}
4

1 回答 1

7

阅读文档总是有帮助的，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标准- 该方法不得具有任何参数，除非是 EJB 拦截器，在这种情况下，它采用 EJB 规范定义的 InvocationC ontext 对象。-方法的返回类型必须是 void。-该方法不得抛出已检查异常...（省略其他要求）

所以，至少不满足返回类型要求（我们不知道你的异常是否被检查，所以我删除了它们以防万一，但在这种情况下你确实需要在方法中处理异常）。

总而言之，将您的方法替换为

@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，您的异常类是检查异常。所以你必须要么在你的方法中引入一个 try-catch 块，要么让你的异常继承自RuntimeException. 如果您选择前一种方式，您可以重新抛出未经检查的异常IllegalStateException，例如，或者发送重定向以防为时已晚：

@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
}
于 2013-11-29T19:41:35.360 回答