Java tutorial
/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0 * * 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 com.android.manifmerger; import static com.android.manifmerger.MergingReport.Record.Severity.ERROR; import static com.android.manifmerger.MergingReport.Record.Severity.WARNING; import static com.android.manifmerger.XmlNode.NodeKey; import com.android.SdkConstants; import com.android.annotations.NonNull; import com.android.xml.AndroidManifest; import com.google.common.base.Joiner; import com.google.common.base.Optional; import com.google.common.base.Strings; import com.google.common.collect.ImmutableList; import org.w3c.dom.Attr; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Validates a loaded {@link XmlDocument} and check for potential inconsistencies in the model due * to user error or omission. * * This is implemented as a separate class so it can be invoked by tools independently from the * merging process. * * This validator will check the state of the loaded xml document before any merging activity is * attempted. It verifies things like a "tools:replace="foo" attribute has a "android:foo" * attribute also declared on the same element (since we want to replace its value). */ public class PreValidator { private PreValidator() { } /** * Validates a loaded {@link com.android.manifmerger.XmlDocument} and return a status of the * merging model. * * Will return one the following status : * <ul> * <li>{@link com.android.manifmerger.MergingReport.Result#SUCCESS} : the merging model is * correct, merging should be attempted</li> * <li>{@link com.android.manifmerger.MergingReport.Result#WARNING} : the merging model * contains non fatal error, user should be notified, merging can be attempted</li> * <li>{@link com.android.manifmerger.MergingReport.Result#ERROR} : the merging model * contains errors, user must be notified, merging should not be attempted</li> * </ul> * * A successful validation does not mean that the merging will be successful, it only means * that the {@link com.android.SdkConstants#TOOLS_URI} instructions are correct and consistent. * * @param mergingReport report to log warnings and errors. * @param xmlDocument the loaded xml part. * @return one the {@link com.android.manifmerger.MergingReport.Result} value. */ @NonNull public static MergingReport.Result validate(@NonNull MergingReport.Builder mergingReport, @NonNull XmlDocument xmlDocument) { validateManifestAttribute(mergingReport, xmlDocument.getRootNode(), xmlDocument.getFileType()); return validate(mergingReport, xmlDocument.getRootNode()); } private static MergingReport.Result validate(MergingReport.Builder mergingReport, XmlElement xmlElement) { validateAttributeInstructions(mergingReport, xmlElement); validateAndroidAttributes(mergingReport, xmlElement); checkSelectorPresence(mergingReport, xmlElement); // create a temporary hash map of children indexed by key to ensure key uniqueness. Map<NodeKey, XmlElement> childrenKeys = new HashMap<NodeKey, XmlElement>(); for (XmlElement childElement : xmlElement.getMergeableElements()) { // if this element is tagged with 'tools:node=removeAll', ensure it has no other // attributes. if (childElement.getOperationType() == NodeOperationType.REMOVE_ALL) { validateRemoveAllOperation(mergingReport, childElement); } else { if (checkKeyPresence(mergingReport, childElement)) { XmlElement twin = childrenKeys.get(childElement.getId()); if (twin != null && !childElement.getType().areMultipleDeclarationAllowed()) { // we have 2 elements with the same identity, if they are equals, // issue a warning, if not, issue an error. String message = String.format( "Element %1$s at %2$s duplicated with element declared at %3$s", childElement.getId(), childElement.printPosition(), childrenKeys.get(childElement.getId()).printPosition()); if (twin.compareTo(childElement).isPresent()) { childElement.addMessage(mergingReport, ERROR, message); } else { childElement.addMessage(mergingReport, WARNING, message); } } childrenKeys.put(childElement.getId(), childElement); } validate(mergingReport, childElement); } } return mergingReport.hasErrors() ? MergingReport.Result.ERROR : MergingReport.Result.SUCCESS; } /** * Validate an xml declaration with 'tools:node="removeAll" annotation. There should not * be any other attribute declaration on this element. */ private static void validateRemoveAllOperation(MergingReport.Builder mergingReport, XmlElement element) { NamedNodeMap attributes = element.getXml().getAttributes(); if (attributes.getLength() > 1) { List<String> extraAttributeNames = new ArrayList<String>(); for (int i = 0; i < attributes.getLength(); i++) { Node item = attributes.item(i); if (!(SdkConstants.TOOLS_URI.equals(item.getNamespaceURI()) && NodeOperationType.NODE_LOCAL_NAME.equals(item.getLocalName()))) { extraAttributeNames.add(item.getNodeName()); } } String message = String.format( "Element %1$s at %2$s annotated with 'tools:node=\"removeAll\"' cannot " + "have other attributes : %3$s", element.getId(), element.printPosition(), Joiner.on(',').join(extraAttributeNames)); element.addMessage(mergingReport, ERROR, message); } } private static void checkSelectorPresence(MergingReport.Builder mergingReport, XmlElement element) { Attr selectorAttribute = element.getXml().getAttributeNodeNS(SdkConstants.TOOLS_URI, Selector.SELECTOR_LOCAL_NAME); if (selectorAttribute != null && !element.supportsSelector()) { String message = String.format("Unsupported tools:selector=\"%1$s\" found on node %2$s at %3$s", selectorAttribute.getValue(), element.getId(), element.printPosition()); element.addMessage(mergingReport, ERROR, message); } } private static void validateManifestAttribute(MergingReport.Builder mergingReport, XmlElement manifest, XmlDocument.Type fileType) { Attr attributeNode = manifest.getXml().getAttributeNode(AndroidManifest.ATTRIBUTE_PACKAGE); // it's ok for an overlay to not have a package name, it's not ok for a main manifest // and it's a warning for a library. if (attributeNode == null && fileType != XmlDocument.Type.OVERLAY) { manifest.addMessage(mergingReport, fileType == XmlDocument.Type.MAIN ? ERROR : WARNING, String.format("Missing 'package' declaration in manifest at %1$s", manifest.printPosition())); } } /** * Checks that an element which is supposed to have a key does have one. * @param mergingReport report to log warnings and errors. * @param xmlElement xml element to check for key presence. * @return true if the element has a valid key or false it does not need one or it is invalid. */ private static boolean checkKeyPresence(MergingReport.Builder mergingReport, XmlElement xmlElement) { ManifestModel.NodeKeyResolver nodeKeyResolver = xmlElement.getType().getNodeKeyResolver(); ImmutableList<String> keyAttributesNames = nodeKeyResolver.getKeyAttributesNames(); if (keyAttributesNames.isEmpty()) { return false; } if (Strings.isNullOrEmpty(xmlElement.getKey())) { // we should have a key but we don't. String message = keyAttributesNames.size() > 1 ? String.format("Missing one of the key attributes '%1$s' on element %2$s at %3$s", Joiner.on(',').join(keyAttributesNames), xmlElement.getId(), xmlElement.printPosition()) : String.format("Missing '%1$s' key attribute on element %2$s at %3$s", keyAttributesNames.get(0), xmlElement.getId(), xmlElement.printPosition()); xmlElement.addMessage(mergingReport, ERROR, message); return false; } return true; } /** * Validate attributes part of the {@link com.android.SdkConstants#ANDROID_URI} * @param mergingReport report to log warnings and errors. * @param xmlElement xml element to check its attributes. */ private static void validateAndroidAttributes(MergingReport.Builder mergingReport, XmlElement xmlElement) { for (XmlAttribute xmlAttribute : xmlElement.getAttributes()) { AttributeModel model = xmlAttribute.getModel(); if (model != null && model.getOnReadValidator() != null) { model.getOnReadValidator().validates(mergingReport, xmlAttribute, xmlAttribute.getValue()); } } } /** * Validates attributes part of the {@link com.android.SdkConstants#TOOLS_URI} * @param mergingReport report to log warnings and errors. * @param xmlElement xml element to check its attributes. */ private static void validateAttributeInstructions(MergingReport.Builder mergingReport, XmlElement xmlElement) { for (Map.Entry<XmlNode.NodeName, AttributeOperationType> attributeOperationTypeEntry : xmlElement .getAttributeOperations()) { Optional<XmlAttribute> attribute = xmlElement.getAttribute(attributeOperationTypeEntry.getKey()); switch (attributeOperationTypeEntry.getValue()) { case STRICT: break; case REMOVE: // check we are not provided a new value. if (attribute.isPresent()) { // Add one to startLine so the first line is displayed as 1. xmlElement.addMessage(mergingReport, ERROR, String.format( "tools:remove specified at line:%d for attribute %s, but " + "attribute also declared at line:%d, " + "do you want to use tools:replace instead ?", xmlElement.getPosition().getStartLine() + 1, attributeOperationTypeEntry.getKey(), attribute.get().getPosition().getStartLine() + 1)); } break; case REPLACE: // check we are provided a new value if (!attribute.isPresent()) { // Add one to startLine so the first line is displayed as 1. xmlElement.addMessage(mergingReport, ERROR, String.format( "tools:replace specified at line:%d for attribute %s, but " + "no new value specified", xmlElement.getPosition().getStartLine() + 1, attributeOperationTypeEntry.getKey())); } break; default: throw new IllegalStateException( "Unhandled AttributeOperationType " + attributeOperationTypeEntry.getValue()); } } } }