Java tutorial
/** * Copyright 2005-2014 The Kuali Foundation * * Licensed under the Educational Community License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.opensource.org/licenses/ecl2.php * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.kuali.rice.krad.web.bind; import org.apache.commons.lang.ArrayUtils; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang3.reflect.FieldUtils; import org.kuali.rice.krad.data.DataObjectService; import org.kuali.rice.krad.data.DataObjectWrapper; import org.kuali.rice.krad.data.KradDataServiceLocator; import org.kuali.rice.krad.data.util.Link; import org.kuali.rice.krad.service.KRADServiceLocatorWeb; import org.kuali.rice.krad.uif.UifConstants; import org.kuali.rice.krad.uif.UifConstants.ViewType; import org.kuali.rice.krad.uif.UifParameters; import org.kuali.rice.krad.uif.service.ViewService; import org.kuali.rice.krad.uif.view.View; import org.kuali.rice.krad.util.KRADUtils; import org.kuali.rice.krad.web.form.UifFormBase; import org.springframework.core.annotation.AnnotationUtils; import org.springframework.core.convert.ConversionService; import org.springframework.util.Assert; import org.springframework.validation.AbstractPropertyBindingResult; import org.springframework.web.bind.ServletRequestDataBinder; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import java.lang.reflect.Field; import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; /** * Override of ServletRequestDataBinder in order to hook in the UifBeanPropertyBindingResult * which instantiates a custom BeanWrapperImpl, and to initialize the view. * * @author Kuali Rice Team (rice.collab@kuali.org) */ public class UifServletRequestDataBinder extends ServletRequestDataBinder { protected static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger .getLogger(UifServletRequestDataBinder.class); private UifBeanPropertyBindingResult bindingResult; private ConversionService conversionService; private DataObjectService dataObjectService; private boolean changeTracking = false; private boolean autoLinking = true; public UifServletRequestDataBinder(Object target) { super(target); this.changeTracking = determineChangeTracking(target); setBindingErrorProcessor(new UifBindingErrorProcessor()); } public UifServletRequestDataBinder(Object target, String name) { super(target, name); this.changeTracking = determineChangeTracking(target); setBindingErrorProcessor(new UifBindingErrorProcessor()); } /** * Return true if the target of this data binder has change tracking enabled. */ private static boolean determineChangeTracking(Object target) { ChangeTracking changeTracking = AnnotationUtils.findAnnotation(target.getClass(), ChangeTracking.class); if (changeTracking != null && changeTracking.enabled()) { return true; } return false; } /** * Allows for a custom binding result class. * * @see org.springframework.validation.DataBinder#initBeanPropertyAccess() */ @Override public void initBeanPropertyAccess() { Assert.state(this.bindingResult == null, "DataBinder is already initialized - call initBeanPropertyAccess before other configuration methods"); this.bindingResult = new UifBeanPropertyBindingResult(getTarget(), getObjectName(), isAutoGrowNestedPaths(), getAutoGrowCollectionLimit()); this.bindingResult.setChangeTracking(this.changeTracking); if (this.conversionService != null) { this.bindingResult.initConversion(this.conversionService); } if (this.dataObjectService == null) { this.dataObjectService = KradDataServiceLocator.getDataObjectService(); } } /** * Allows for the setting attributes to use to find the data dictionary data from Kuali * * @see org.springframework.validation.DataBinder#getInternalBindingResult() */ @Override protected AbstractPropertyBindingResult getInternalBindingResult() { if (this.bindingResult == null) { initBeanPropertyAccess(); } return this.bindingResult; } /** * Disallows direct field access for Kuali * * @see org.springframework.validation.DataBinder#initDirectFieldAccess() */ @Override public void initDirectFieldAccess() { LOG.error("Direct Field access is not allowed in UifServletRequestDataBinder."); throw new RuntimeException("Direct Field access is not allowed in Kuali"); } /** * Helper method to facilitate calling super.bind() from {@link #bind(ServletRequest)}. */ private void _bind(ServletRequest request) { super.bind(request); } /** * Calls {@link org.kuali.rice.krad.web.form.UifFormBase#preBind(HttpServletRequest)}, Performs data binding * from servlet request parameters to the form, initializes view object, then calls * {@link org.kuali.rice.krad.web.form.UifFormBase#postBind(javax.servlet.http.HttpServletRequest)} * * <p> * The view is initialized by first looking for the {@code viewId} parameter in the request. If found, the view is * retrieved based on this id. If the id is not present, then an attempt is made to find a view by type. In order * to retrieve a view based on type, the view request parameter {@code viewTypeName} must be present. If all else * fails and the viewId is populated on the form (could be populated from a previous request), this is used to * retrieve the view. * </p> * * @param request - HTTP Servlet Request instance */ @Override public void bind(ServletRequest request) { UifFormBase form = (UifFormBase) UifServletRequestDataBinder.this.getTarget(); request.setAttribute(UifConstants.REQUEST_FORM, form); form.preBind((HttpServletRequest) request); _bind(request); request.setAttribute(UifConstants.PROPERTY_EDITOR_REGISTRY, this.bindingResult.getPropertyEditorRegistry()); executeAutomaticLinking(request, form); if (!form.isUpdateNoneRequest()) { // attempt to retrieve a view by unique identifier first, either as request attribute or parameter String viewId = (String) request.getAttribute(UifParameters.VIEW_ID); if (StringUtils.isBlank(viewId)) { viewId = request.getParameter(UifParameters.VIEW_ID); } View view = null; if (StringUtils.isNotBlank(viewId)) { view = getViewService().getViewById(viewId); } // attempt to get view instance by type parameters if (view == null) { view = getViewByType(request, form); } // if view not found attempt to find one based on the cached form if (view == null) { view = getViewFromPreviousModel(form); if (view != null) { LOG.warn("Obtained viewId from cached form, this may not be safe!"); } } if (view != null) { form.setViewId(view.getId()); } else { form.setViewId(null); } form.setView(view); } // invoke form callback for custom binding form.postBind((HttpServletRequest) request); } /** * Performs automatic reference linking of the given form based on the properties on the form for which linking * is enabled. * * <p>Linking will only be performed if change tracking and auto linking are enabled on this data binder.</p> * * @param request request instance * @param form form instance against which to perform automatic linking */ protected void executeAutomaticLinking(ServletRequest request, UifFormBase form) { if (!changeTracking) { LOG.info("Skip automatic linking because change tracking not enabled for this form."); return; } if (!autoLinking) { LOG.info("Skip automatic linking because it has been disabled for this form"); return; } Set<String> autoLinkingPaths = determineRootAutoLinkingPaths(form.getClass(), null, new HashSet<Class<?>>()); List<AutoLinkTarget> targets = extractAutoLinkTargets(autoLinkingPaths); // perform linking for each target for (AutoLinkTarget target : targets) { if (!dataObjectService.supports(target.getTarget().getClass())) { LOG.warn("Encountered an auto linking target that is not a valid data object: " + target.getTarget().getClass()); } else { DataObjectWrapper<?> wrapped = dataObjectService.wrap(target.getTarget()); wrapped.linkChanges(target.getModifiedPropertyPaths()); } } } /** * Determines the root property paths relative to the given root object type against which to perform automatic * linking. * * <p>This will be determined based on the presence of {@link Link} annotations on the given root object type. * This method is invoked recursively as it walks the class structure looking for Link annotations. It uses the * path * and scanned arguments to keep track of how deep into the structure the scanning is and to prevent infinite * recursion.</p> * * @param rootObjectType the root object type from which to perform the scan for auto-linking paths * @param path the current property path relative to the original root object type at which the scan began, if null * then we are scanning from the root-most object type. Each recursive call of this method will append * a new property to this path * @param scanned used to track classes that have already been scanned and prevent infinite recursion * @return a set of property paths that should be auto linked */ protected Set<String> determineRootAutoLinkingPaths(Class<?> rootObjectType, String path, Set<Class<?>> scanned) { Set<String> autoLinkingPaths = new HashSet<String>(); if (scanned.contains(rootObjectType)) { return autoLinkingPaths; } else { scanned.add(rootObjectType); } Link autoLink = AnnotationUtils.findAnnotation(rootObjectType, Link.class); if (autoLink != null && autoLink.cascade()) { autoLinkingPaths.addAll(assembleAutoLinkingPaths(path, autoLink)); } else if (autoLink == null) { Field[] fields = FieldUtils.getAllFields(rootObjectType); for (Field field : fields) { autoLink = field.getAnnotation(Link.class); if (autoLink != null) { if (autoLink.cascade()) { String fieldPath = appendToPath(path, field.getName()); autoLinkingPaths.addAll(assembleAutoLinkingPaths(fieldPath, autoLink)); } } else { autoLinkingPaths.addAll(determineRootAutoLinkingPaths(field.getType(), appendToPath(path, field.getName()), scanned)); } } } return autoLinkingPaths; } /** * A helper method which simply assembles a set of property paths for the given {@link Link} annotation which * should * be auto linked. * * @param path the property path from the top-most root class to where the Link annotation was found during the * scan * @param autoLink the Link annotation which is being processed * @return a Set of auto linking paths based on the given path parameter, plus the path(s) defined on the * {@link Link} annotation */ protected Set<String> assembleAutoLinkingPaths(String path, Link autoLink) { Set<String> autoLinkingPaths = new HashSet<String>(); if (ArrayUtils.isEmpty(autoLink.path())) { autoLinkingPaths.add(path); } else { for (String autoLinkingPath : autoLink.path()) { autoLinkingPaths.add(appendToPath(path, autoLinkingPath)); } } return autoLinkingPaths; } /** * Uses the binding result on this data binder to determine the targets on the form that automatic linking should * be performed against. * * <p>Only those property paths for which auto linking is enabled and which were actually modified during the * execution of this data binding will be returned from this method.</p> * * @param autoLinkingPaths a set of paths relative to the form class for which auto-linking has been enabled * @return a list of {@link AutoLinkTarget} objects which contain an object to be linked and which properties on * that object were modified during this data binding execution */ protected List<AutoLinkTarget> extractAutoLinkTargets(Set<String> autoLinkingPaths) { List<AutoLinkTarget> targets = new ArrayList<AutoLinkTarget>(); for (String autoLinkingPath : autoLinkingPaths) { Object targetObject = getInternalBindingResult().getPropertyAccessor() .getPropertyValue(autoLinkingPath); if (targetObject == null) { continue; } if (targetObject instanceof Map) { targets.addAll(extractAutoLinkMapTargets(autoLinkingPath, (Map<?, ?>) targetObject)); continue; } if (targetObject instanceof List) { targets.addAll(extractAutoLinkListTargets(autoLinkingPath, (List<?>) targetObject)); continue; } Set<String> modifiedAutoLinkingPaths = new HashSet<String>(); Set<String> modifiedPaths = ((UifBeanPropertyBindingResult) getInternalBindingResult()) .getModifiedPaths(); for (String modifiedPath : modifiedPaths) { if (modifiedPath.startsWith(autoLinkingPath)) { modifiedAutoLinkingPaths.add(modifiedPath.substring(autoLinkingPath.length() + 1)); } } targets.add(new AutoLinkTarget(targetObject, modifiedAutoLinkingPaths)); } return targets; } /** * For the map object indicated for linking, iterates through the modified paths and finds paths that match * entries in the map, and if found adds an auto link target. * * @param autoLinkingPath path configured for auto linking * @param targetMap map object for the linking path * @return List of auto linking targets to process */ protected List<AutoLinkTarget> extractAutoLinkMapTargets(String autoLinkingPath, Map<?, ?> targetMap) { List<AutoLinkTarget> targets = new ArrayList<AutoLinkTarget>(); Set<String> modifiedPaths = ((UifBeanPropertyBindingResult) getInternalBindingResult()).getModifiedPaths(); for (Map.Entry<?, ?> targetMapEntry : targetMap.entrySet()) { Set<String> modifiedAutoLinkingPaths = new HashSet<String>(); for (String modifiedPath : modifiedPaths) { String targetPathMatch = autoLinkingPath + "['" + targetMapEntry.getKey() + "']"; if (modifiedPath.startsWith(targetPathMatch)) { modifiedAutoLinkingPaths.add(modifiedPath.substring(targetPathMatch.length() + 1)); } } if (!modifiedAutoLinkingPaths.isEmpty()) { targets.add(new AutoLinkTarget(targetMapEntry.getValue(), modifiedAutoLinkingPaths)); } } return targets; } /** * For the list object indicated for linking, iterates through the modified paths and finds paths that match * entries in the list, and if found adds an auto link target. * * @param autoLinkingPath path configured for auto linking * @param targetList list object for the linking path * @return List of auto linking targets to process */ protected List<AutoLinkTarget> extractAutoLinkListTargets(String autoLinkingPath, List<?> targetList) { List<AutoLinkTarget> targets = new ArrayList<AutoLinkTarget>(); Set<String> modifiedPaths = ((UifBeanPropertyBindingResult) getInternalBindingResult()).getModifiedPaths(); for (int i = 0; i < targetList.size(); i++) { Set<String> modifiedAutoLinkingPaths = new HashSet<String>(); for (String modifiedPath : modifiedPaths) { String targetPathMatch = autoLinkingPath + "[" + i + "]"; if (modifiedPath.startsWith(targetPathMatch)) { modifiedAutoLinkingPaths.add(modifiedPath.substring(targetPathMatch.length() + 1)); } } if (!modifiedAutoLinkingPaths.isEmpty()) { targets.add(new AutoLinkTarget(targetList.get(i), modifiedAutoLinkingPaths)); } } return targets; } /** * A utility method which appends two property paths together to create a new nested property path. * * <p>Handles null values for either the path or pathElement. The general output will be path.pathElement * except in situations where either of the two given values are empty or null, in which case only the non-null * value will be returned.</p> * * @param path the prefix of the property path * @param pathElement the suffix of the property path to append to the given path * @return an appended path, appended with a "." between the given path and pathElement (unless one of these is * null) */ private String appendToPath(String path, String pathElement) { if (StringUtils.isEmpty(path)) { return pathElement; } else if (StringUtils.isEmpty(pathElement)) { return path; } return path + "." + pathElement; } /** * Attempts to get a view instance by looking for a view type name in the request or the form and querying * that view type with the request parameters * * @param request request instance to pull parameters from * @param form form instance to pull values from * @return View instance if found or null */ protected View getViewByType(ServletRequest request, UifFormBase form) { View view = null; String viewTypeName = request.getParameter(UifParameters.VIEW_TYPE_NAME); ViewType viewType = StringUtils.isBlank(viewTypeName) ? form.getViewTypeName() : ViewType.valueOf(viewTypeName); if (viewType != null) { Map<String, String> parameterMap = KRADUtils.translateRequestParameterMap(request.getParameterMap()); view = getViewService().getViewByType(viewType, parameterMap); } return view; } /** * Attempts to get a view instance based on the view id stored on the form (which might not be populated * from the request but remaining from session) * * @param form form instance to pull view id from * @return View instance associated with form's view id or null if id or view not found */ protected View getViewFromPreviousModel(UifFormBase form) { // maybe we have a view id from the session form if (form.getViewId() != null) { return getViewService().getViewById(form.getViewId()); } return null; } public boolean isChangeTracking() { return changeTracking; } public boolean isAutoLinking() { return autoLinking; } public void setAutoLinking(boolean autoLinking) { this.autoLinking = autoLinking; } public ViewService getViewService() { return KRADServiceLocatorWeb.getViewService(); } public DataObjectService getDataObjectService() { return this.dataObjectService; } public void setDataObjectService(DataObjectService dataObjectService) { this.dataObjectService = dataObjectService; } /** * Holds an object that will have auto-linking executed against it. * * <p>Also contains a set of property paths (relative to the object) that were modified during the data binding * execution.</p> */ private static final class AutoLinkTarget { private final Object target; private final Set<String> modifiedPropertyPaths; AutoLinkTarget(Object target, Set<String> modifiedPropertyPaths) { this.target = target; this.modifiedPropertyPaths = modifiedPropertyPaths; } Object getTarget() { return target; } Set<String> getModifiedPropertyPaths() { return Collections.unmodifiableSet(modifiedPropertyPaths); } } }