子列表索引出界限异常

每当我运行我的xhtml。它给了我以下例外。 statusindex对象的值是5.我正在使用JQuery进行惰性滚动，所以当我的xhml页面getMoreStatusList调用getMoreStatusList函数时，它给了我一个超出绑定异常的索引。数据库中有26个状态更新，所以索引超出界限的异常对我来说毫无意义。子列表索引出界限异常

1）代码

public List<Status> getMoreStatusList() { 

    FacesContext context = FacesContext.getCurrentInstance(); 
    HttpSession session = (HttpSession) context.getExternalContext() 
      .getSession(false); 
    User user = (User) session.getAttribute("userdet"); 
    Query query = em.createQuery("SELECT s FROM Status s WHERE s.email='" 
      + user.getEmail() + "' ORDER BY s.timeMillis desc", 
      Status.class); 
    List<Status> results = query.getResultList(); 
    Query query1 = em.createQuery("SELECT f FROM Friend f WHERE f.email='" 
      + user.getEmail() + "'", Friend.class); 
    List<Friend> results1 = query1.getResultList(); 
    Iterator<Friend> it = results1.listIterator(); 
    while (it.hasNext()) { 
     String email = it.next().getFriendEmail(); 
     Query query2 = em.createQuery(
       "SELECT s FROM Status s WHERE s.email='" + email 
         + "' ORDER BY s.timeMillis desc", Status.class); 
     List<Status> results2 = query2.getResultList(); 
     results.addAll(results2); 

    } 
    Collections.sort(results); 
    int index = (int) session.getAttribute("statusindex"); 
    System.out.println(index); 
    results = results.subList(index,index+5); 
    session.setAttribute("statusindex", index + 5); 
    return results; 

}

2）异常

Mar 02, 2013 9:31:58 PM org.apache.catalina.core.StandardWrapperValve invoke 
SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/FreeBird_v.6] threw exception [/getMoreStatusList.xhtml @120,43 test="#{p.videostatus!=null}" /getMoreStatusList.xhtml @120,43 test="#{p.videostatus!=null}": /getMoreStatusList.xhtml @14,60 items="#{statusBean.moreStatusList}": Error reading 'moreStatusList' on type com.bean.StatusBean] with root cause 
java.lang.IndexOutOfBoundsException: toIndex = 30 
    at java.util.SubList.<init>(Unknown Source) 
    at java.util.RandomAccessSubList.<init>(Unknown Source) 
    at java.util.AbstractList.subList(Unknown Source) 
    at java.util.Vector.subList(Unknown Source) 
    at com.bean.StatusBean.getMoreStatusList(StatusBean.java:190) 
    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 javax.el.BeanELResolver.getValue(BeanELResolver.java:87) 
    at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:67) 
    at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:71) 
    at org.apache.el.parser.AstValue.getValue(AstValue.java:169) 
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189) 
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:106) 
    at com.sun.faces.facelets.tag.jstl.core.IndexedValueExpression.getValue(IndexedValueExpression.java:89) 
    at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:68) 
    at org.apache.el.parser.AstValue.getValue(AstValue.java:147) 
    at org.apache.el.parser.AstNotEqual.getValue(AstNotEqual.java:38) 
    at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189) 
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:106) 
    at com.sun.faces.facelets.tag.TagAttributeImpl.getObject(TagAttributeImpl.java:326) 
    at com.sun.faces.facelets.tag.TagAttributeImpl.getBoolean(TagAttributeImpl.java:133) 
    at com.sun.faces.facelets.tag.jstl.core.IfHandler.apply(IfHandler.java:88) 
    at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:94) 
    at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:131) 
    at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:162) 
    at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:114) 
    at com.sun.faces.facelets.tag.jstl.core.ForEachHandler.apply(ForEachHandler.java:214) 
    at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:131) 
    at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:162) 
    at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:114) 
    at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:94) 
    at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:89) 
    at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:94) 
    at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:79) 
    at com.sun.faces.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:148) 
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.buildView(FaceletViewHandlingStrategy.java:734) 
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:96) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) 
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:135) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:309) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
    at java.lang.Thread.run(Unknown Source)

来源

2013-03-02 Wizard Sultan

消息指出toIndex是30.这意味着，statusindex不是5，因为你相信它是，但25：

java.lang.IndexOutOfBoundsException: toIndex = 30

侧面说明，你应该使用命名参数你查询而不是字符串连接来传递参数。您的代码容易受到SQL注入攻击。如果电子邮件地址恰好包含单引号，它也会失败。

来源

2013-03-02 16:29:15

你说得对，我在控制台打印了索引的值，它给了我25，但我仍然不明白它的方式它正在变成25，我通过 5作为会话对象通过下面的代码'session.setAttribute（“statusindex”，5）;' – 2013-03-02 16:41:49

但是你每次调用方法时增加它：'session.setAttribute（“statusindex” ，index + 5）;' – 2013-03-02 16:44:00

但是为什么我在第一次调用该方法时遇到了异常。 – 2013-03-02 16:49:21

results = results.subList(index,index+5);

所以会做：

results.subList(25,30);如果通过25，因此错误。

来源

2013-03-02 16:29:06

当我打电话给getMoreStatusList我传递5和10作为参数 'results.subList（5,10 ）'; – 2013-03-02 16:32:31

不，你不是。如果你是，你不会有一个例外，说'toIndex'是30. – 2013-03-02 16:34:31

List.subList()的文档是很清楚的：

抛出：IndexOutOfBoundsException - 一个非法的端点索引值（fromIndex < 0 || toIndex > size || fromIndex > toIndex）

在你的情况，toIndex > size：

java.lang.IndexOutOfBoundsException: toIndex = 30

来源

2013-03-02 16:30:32 NPE

子列表索引出界限异常

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