我使用PrimeFaces数据表通过LazyDataModel从我的数据库加载数据。这一直很完美。但最近我遇到了一个奇怪的问题，当我稍微改变了代码。我认为这与JSF / PrimeFaces无关。
问题在于，每当我在filterCondition = cb.or(filterCondition, cb.like(path, value))方法中使用getFilterCondition()时，我都会在底部显示异常。但是，每当我使用and()代替or()时，每次操作都会完美无缺。
另外。我在Eclipse中以调试模式运行它，eclipse找不到任何变量或值为null。
这是代码：
@Override
public List<Application> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters) {
List<Application> data = new ArrayList<Application>();
try {
dao.beginTransaction();
data = getResultList(first, pageSize, sortField, sortOrder, getFilters());
setRowCount(count(getFilters()));
dao.commit();
} catch (Exception e) {
e.printStackTrace();
}
return data;
}
private Predicate getFilterCondition(CriteriaBuilder cb, Root<Application> myObj, Map<String, Object> filters) {
Predicate filterCondition = cb.conjunction();
String wildCard = "%";
for (Entry<String, Object> filter : filters.entrySet()) {
String value = wildCard + filter.getValue() + wildCard;
if(filter.getValue().getClass().equals(String.class)) {
if (!filter.getValue().equals("")) {
Path<String> path = getPath(cb, filter.getKey(), myObj);
filterCondition = cb.or(filterCondition, cb.like(path, value));
// filterCondition = cb.and(filterCondition, cb.like(path, value)); <--- Working
}
}
}
return filterCondition;
}
public int count(Map<String, Object> filters) {
CriteriaBuilder cb = dao.getEntityManager().getCriteriaBuilder();
CriteriaQuery<Long> cq = cb.createQuery(Long.class);
Root<Application> myObj = cq.from(Application.class);
cq.where(getFilterCondition(cb, myObj, filters));
cq.select(cb.count(myObj));
return dao.getEntityManager().createQuery(cq).getSingleResult().intValue();
}
public List<Application> getResultList(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, Object> filters) {
CriteriaBuilder cb = dao.getEntityManager().getCriteriaBuilder();
CriteriaQuery<Application> cq = cb.createQuery(Application.class);
Root<Application> myObj = cq.from(Application.class);
q.where(getFilterCondition(cb, myObj, filters));
if (sortField != null) {
Path<?> path = getPath(cb, sortField, myObj);
if (sortOrder == SortOrder.ASCENDING) {
cq.orderBy(cb.asc(path));
} else {
cq.orderBy(cb.desc(path));
}
}
return dao.getEntityManager().createQuery(cq).setFirstResult(first).setMaxResults(pageSize).getResultList();
}
private Path<String> getPath(CriteriaBuilder cb, String field, Root<Application> app) {
Path<String> path = null;
if (field == null) {
path = app.get(Application_.appName);
} else {
if (field.equals("appName")) {
path = app.get(Application_.appName);
} else if (field.equals("contextRoot")) {
path = app.get(Application_.contextRoot);
} else if (field.equals("moduleMappings")) {
path = app.get(Application_.moduleMappings);
} else if (field.equals("virtualHost")) {
path = app.get(Application_.virtualHost);
} else if (field.equals("vhAliases")) {
path = app.get(Application_.vhAliases);
} else if (field.equals("server.serverName")) {
path = app.join("server", JoinType.LEFT).get("serverName");
} else if (field.equals("cluster.clusterName")) {
path = app.join("cluster", JoinType.LEFT).get("clusterName");
} else if (field.equals("cell.cellName")) {
path = app.join("cell", JoinType.LEFT).get("cellName");
} else if (field.equals("cell.stage")) {
path = app.join("cell", JoinType.LEFT).get("stage");
} else if (field.equals("cell.zone")) {
path = app.join("cell", JoinType.LEFT).get("zone");
} else if (field.equals("cell.cellVersion")) {
path = app.join("cell", JoinType.LEFT).get("cellVersion");
}
}
return path;
}
抛出异常：
[2014-09-23 09:34:09:782 CEST] 0000009f SystemErr R java.lang.NullPointerException
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.eclipse.persistence.internal.jpa.querydef.CriteriaBuilderImpl.or(CriteriaBuilderImpl.java:413)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at net.wasreport.models.ApplicationLazyModel.getFilterCondition(ApplicationLazyModel.java:99)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at net.wasreport.models.ApplicationLazyModel.getResultList(ApplicationLazyModel.java:125)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at net.wasreport.models.ApplicationLazyModel.load(ApplicationLazyModel.java:75)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.component.datatable.DataTable.loadLazyData(DataTable.java:818)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.component.datatable.DataTableRenderer.preRender(DataTableRenderer.java:94)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:82)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:535)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at javax.faces.component.UIData.encodeEnd(UIData.java:867)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:85)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:68)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.primefaces.component.outputpanel.OutputPanelRenderer.encodeEnd(OutputPanelRenderer.java:37)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:535)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.encodeAll(UIComponent.java:626)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.apache.myfaces.context.servlet.PartialViewContextImpl$PhaseAwareVisitCallback.processRenderComponent(PartialViewContextImpl.java:559)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.apache.myfaces.context.servlet.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:537)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at org.apache.myfaces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:207)
[2014-09-23 09:34:09:783 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.visitTree(UIComponent.java:773)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1007)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIForm.visitTree(UIForm.java:269)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.visitTree(UIComponent.java:793)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1007)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.visitTree(UIComponent.java:793)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1007)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.visitTree(UIComponent.java:793)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1007)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.visitTree(UIComponent.java:793)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponentBase.visitTree(UIComponentBase.java:1007)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.context.servlet.PartialViewContextImpl.processPartialRendering(PartialViewContextImpl.java:426)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.context.servlet.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:346)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.primefaces.context.PrimePartialViewContext.processPartial(PrimePartialViewContext.java:60)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:390)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.component.UIComponent.encodeAll(UIComponent.java:617)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.renderView(FaceletViewDeclarationLanguage.java:1320)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:263)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:85)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:240)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at javax.faces.webapp.FacesServlet.service(FacesServlet.java:191)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1227)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:776)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:458)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)
[2014-09-23 09:34:09:784 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1032)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:87)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:909)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1662)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:200)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:459)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:526)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:312)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:88)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:175)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
[2014-09-23 09:34:09:785 CEST] 0000009f SystemErr R at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1862)