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/*
* Copyright (C) 2011 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 com.android.common.annotations.NonNull;
import com.android.common.annotations.Nullable;
import com.android.manifmerger.IMergerLog.FileAndLine;
import com.android.manifmerger.IMergerLog.Severity;
import com.android.common.utils.ILogger;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXParseException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
/**
* A few XML handling utilities.
*/
public class XmlUtils {
private static final String DATA_ORIGIN_FILE = "manif.merger.file"; //$NON-NLS-1$
private static final String DATA_FILE_NAME = "manif.merger.filename"; //$NON-NLS-1$
private static final String DATA_LINE_NUMBER = "manif.merger.line#"; //$NON-NLS-1$
/**
* Parses the given XML file as a DOM document.
* The parser does not validate the DTD nor any kind of schema.
* It is namespace aware.
* <p/>
* This adds a user tag with the original {@link java.io.File} to the returned document.
* You can retrieve this file later by using {@link #extractXmlFilename(org.w3c.dom.Node)}.
*
* @param xmlFile The XML {@link java.io.File} to parse. Must not be null.
* @param log An {@link ILogger} for reporting errors. Must not be null.
* @return A new DOM {@link org.w3c.dom.Document}, or null.
*/
@Nullable
static Document parseDocument(@NonNull final File xmlFile, @NonNull final IMergerLog log) {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
InputSource is = new InputSource(new FileReader(xmlFile));
factory.setNamespaceAware(true);
factory.setValidating(false);
DocumentBuilder builder = factory.newDocumentBuilder();
// We don't want the default handler which prints errors to stderr.
builder.setErrorHandler(new ErrorHandler() {
@Override
public void warning(SAXParseException e) {
log.error(Severity.WARNING,
new FileAndLine(xmlFile.getAbsolutePath(), 0),
"Warning when parsing: %1$s",
e.toString());
}
@Override
public void fatalError(SAXParseException e) {
log.error(Severity.ERROR,
new FileAndLine(xmlFile.getAbsolutePath(), 0),
"Fatal error when parsing: %1$s",
xmlFile.getName(), e.toString());
}
@Override
public void error(SAXParseException e) {
log.error(Severity.ERROR,
new FileAndLine(xmlFile.getAbsolutePath(), 0),
"Error when parsing: %1$s",
e.toString());
}
});
Document doc = builder.parse(is);
doc.setUserData(DATA_ORIGIN_FILE, xmlFile, null /*handler*/);
findLineNumbers(doc, 1);
return doc;
} catch (FileNotFoundException e) {
log.error(Severity.ERROR,
new FileAndLine(xmlFile.getAbsolutePath(), 0),
"XML file not found");
} catch (Exception e) {
log.error(Severity.ERROR,
new FileAndLine(xmlFile.getAbsolutePath(), 0),
"Failed to parse XML file: %1$s",
e.toString());
}
return null;
}
/**
* Parses the given XML string as a DOM document.
* The parser does not validate the DTD nor any kind of schema.
* It is namespace aware.
*
* @param xml The XML string to parse. Must not be null.
* @param log An {@link ILogger} for reporting errors. Must not be null.
* @return A new DOM {@link org.w3c.dom.Document}, or null.
*/
@Nullable
static Document parseDocument(@NonNull String xml,
@NonNull IMergerLog log,
@NonNull FileAndLine errorContext) {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
InputSource is = new InputSource(new StringReader(xml));
factory.setNamespaceAware(true);
factory.setValidating(false);
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(is);
findLineNumbers(doc, 1);
return doc;
} catch (Exception e) {
log.error(Severity.ERROR, errorContext, "Failed to parse XML string");
}
return null;
}
/**
* Decorates the document with the specified file name, which can be
* retrieved later by calling {@link #extractLineNumber(org.w3c.dom.Node)}.
* <p/>
* It also tries to add line number information, with the caveat that the
* current implementation is a gross approximation.
* <p/>
* There is no need to call this after calling one of the {@code parseDocument()}
* methods since they already decorated their own document.
*
* @param doc The document to decorate.
* @param fileName The name to retrieve later for that document.
*/
static void decorateDocument(@NonNull Document doc, @NonNull String fileName) {
doc.setUserData(DATA_FILE_NAME, fileName, null /*handler*/);
findLineNumbers(doc, 1);
}
/**
* Extracts the origin {@link java.io.File} that {@link #parseDocument(java.io.File, com.android.manifmerger.IMergerLog)}
* added to the XML document or the string added by
*
* @param xmlNode Any node from a document returned by {@link #parseDocument(java.io.File, com.android.manifmerger.IMergerLog)}.
* @return The {@link java.io.File} object used to create the document or null.
*/
@Nullable
static String extractXmlFilename(@Nullable Node xmlNode) {
if (xmlNode != null && xmlNode.getNodeType() != Node.DOCUMENT_NODE) {
xmlNode = xmlNode.getOwnerDocument();
}
if (xmlNode != null) {
Object data = xmlNode.getUserData(DATA_ORIGIN_FILE);
if (data instanceof File) {
return ((File) data).getName();
}
data = xmlNode.getUserData(DATA_FILE_NAME);
if (data instanceof String) {
return (String) data;
}
}
return null;
}
/**
* This is a CRUDE INEXACT HACK to decorate the DOM with some kind of line number
* information for elements. It's inexact because by the time we get the DOM we
* already have lost all the information about whitespace between attributes.
* <p/>
* Also we don't even try to deal with \n vs \r vs \r\n insanity. This only counts
* the \n occurring in text nodes to determine line advances, which is clearly flawed.
* <p/>
* However it's good enough for testing, and we'll replace it by a PositionXmlParser
* once it's moved into com.android.util.
*/
private static int findLineNumbers(Node node, int line) {
for (; node != null; node = node.getNextSibling()) {
node.setUserData(DATA_LINE_NUMBER, Integer.valueOf(line), null /*handler*/);
if (node.getNodeType() == Node.TEXT_NODE) {
String text = node.getNodeValue();
if (text.length() > 0) {
for (int pos = 0; (pos = text.indexOf('\n', pos)) != -1; pos++) {
++line;
}
}
}
Node child = node.getFirstChild();
if (child != null) {
line = findLineNumbers(child, line);
}
}
return line;
}
/**
* Extracts the line number that {@link #findLineNumbers} added to the XML nodes.
*
* @param xmlNode Any node from a document returned by {@link #parseDocument(java.io.File, com.android.manifmerger.IMergerLog)}.
* @return The line number if found or 0.
*/
static int extractLineNumber(@Nullable Node xmlNode) {
if (xmlNode != null) {
Object data = xmlNode.getUserData(DATA_LINE_NUMBER);
if (data instanceof Integer) {
return ((Integer) data).intValue();
}
}
return 0;
}
/**
* Find the prefix for the given NS_URI in the document.
*
* @param doc The document root.
* @param nsUri The Namespace URI to look for.
* @return The namespace prefix if found or null.
*/
static String lookupNsPrefix(Document doc, String nsUri) {
return com.android.common.utils.XmlUtils.lookupNamespacePrefix(doc, nsUri);
}
/**
* Outputs the given XML {@link org.w3c.dom.Document} to the file {@code outFile}.
*
* TODO right now reformats the document. Needs to output as-is, respecting white-space.
*
* @param doc The document to output. Must not be null.
* @param outFile The {@link java.io.File} where to write the document.
* @param log A log in case of error.
* @return True if the file was written, false in case of error.
*/
static boolean printXmlFile(
@NonNull Document doc,
@NonNull File outFile,
@NonNull IMergerLog log) {
// Quick thing based on comments from http://stackoverflow.com/questions/139076
try {
Transformer tf = TransformerFactory.newInstance().newTransformer();
tf.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); //$NON-NLS-1$
tf.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
tf.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$
tf.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", //$NON-NLS-1$
"4"); //$NON-NLS-1$
tf.transform(new DOMSource(doc), new StreamResult(outFile));
return true;
} catch (TransformerException e) {
log.error(Severity.ERROR,
new FileAndLine(outFile.getName(), 0),
"Failed to write XML file: %1$s",
e.toString());
return false;
}
}
/**
* Outputs the given XML {@link org.w3c.dom.Document} as a string.
*
* TODO right now reformats the document. Needs to output as-is, respecting white-space.
*
* @param doc The document to output. Must not be null.
* @param log A log in case of error.
* @return A string representation of the XML. Null in case of error.
*/
static String printXmlString(
@NonNull Document doc,
@NonNull IMergerLog log) {
try {
Transformer tf = TransformerFactory.newInstance().newTransformer();
tf.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); //$NON-NLS-1$
tf.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
tf.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$
tf.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", //$NON-NLS-1$
"4"); //$NON-NLS-1$
StringWriter sw = new StringWriter();
tf.transform(new DOMSource(doc), new StreamResult(sw));
return sw.toString();
} catch (TransformerException e) {
log.error(Severity.ERROR,
new FileAndLine(extractXmlFilename(doc), 0),
"Failed to write XML file: %1$s",
e.toString());
return null;
}
}
/**
* Dumps the structure of the DOM to a simple text string.
*
* @param node The first node to dump (recursively). Can be null.
* @param nextSiblings If true, will also dump the following siblings.
* If false, it will just process the given node.
* @return A string representation of the Node structure, useful for debugging.
*/
@NonNull
static String dump(@Nullable Node node, boolean nextSiblings) {
return dump(node, 0 /*offset*/, nextSiblings, true /*deep*/, null /*keyAttr*/);
}
/**
* Dumps the structure of the DOM to a simple text string.
* Each line is terminated with a \n separator.
*
* @param node The first node to dump. Can be null.
* @param offsetIndex The offset to add at the begining of each line. Each offset is
* converted into 2 space characters.
* @param nextSiblings If true, will also dump the following siblings.
* If false, it will just process the given node.
* @param deep If true, this will recurse into children.
* @param keyAttr An optional attribute *local* name to insert when writing an element.
* For example when writing an Activity, it helps to always insert "name" attribute.
* @return A string representation of the Node structure, useful for debugging.
*/
@NonNull
static String dump(
@Nullable Node node,
int offsetIndex,
boolean nextSiblings,
boolean deep,
@Nullable String keyAttr) {
StringBuilder sb = new StringBuilder();
String offset = ""; //$NON-NLS-1$
for (int i = 0; i < offsetIndex; i++) {
offset += " "; //$NON-NLS-1$
}
if (node == null) {
sb.append(offset).append("(end reached)\n");
} else {
for (; node != null; node = node.getNextSibling()) {
String type = null;
short t = node.getNodeType();
switch(t) {
case Node.ELEMENT_NODE:
String attr = "";
if (keyAttr != null) {
NamedNodeMap attrs = node.getAttributes();
if (attrs != null) {
for (int i = 0; i < attrs.getLength(); i++) {
Node a = attrs.item(i);
if (a != null && keyAttr.equals(a.getLocalName())) {
attr = String.format(" %1$s=%2$s",
a.getNodeName(), a.getNodeValue());
break;
}
}
}
}
sb.append(String.format("%1$s<%2$s%3$s>\n",
offset, node.getNodeName(), attr));
break;
case Node.COMMENT_NODE:
sb.append(String.format("%1$s<!-- %2$s -->\n",
offset, node.getNodeValue()));
break;
case Node.TEXT_NODE:
String txt = node.getNodeValue().trim();
if (txt.length() == 0) {
// Keep this for debugging. TODO make it a flag
// to dump whitespace on debugging. Otherwise ignore it.
// txt = "[whitespace]";
break;
}
sb.append(String.format("%1$s%2$s\n", offset, txt));
break;
case Node.ATTRIBUTE_NODE:
sb.append(String.format("%1$s @%2$s = %3$s\n",
offset, node.getNodeName(), node.getNodeValue()));
break;
case Node.CDATA_SECTION_NODE:
type = "cdata"; //$NON-NLS-1$
break;
case Node.DOCUMENT_NODE:
type = "document"; //$NON-NLS-1$
break;
case Node.PROCESSING_INSTRUCTION_NODE:
type = "PI"; //$NON-NLS-1$
break;
default:
type = Integer.toString(t);
}
if (type != null) {
sb.append(String.format("%1$s[%2$s] <%3$s> %4$s\n",
offset, type, node.getNodeName(), node.getNodeValue()));
}
if (deep) {
List<Attr> attrs = sortedAttributeList(node.getAttributes());
for (Attr attr : attrs) {
sb.append(String.format("%1$s @%2$s = %3$s\n",
offset, attr.getNodeName(), attr.getNodeValue()));
}
Node child = node.getFirstChild();
if (child != null) {
sb.append(dump(child, offsetIndex+1, true, true, keyAttr));
}
}
if (!nextSiblings) {
break;
}
}
}
return sb.toString();
}
/**
* Returns a sorted list of attributes.
* The list is never null and does not contain null items.
*
* @param attrMap A Node map as returned by {@link org.w3c.dom.Node#getAttributes()}.
* Can be null, in which case an empty list is returned.
* @return A non-null, possible empty, list of all nodes that are actual {@link org.w3c.dom.Attr},
* sorted by increasing attribute name.
*/
@NonNull
public static List<Attr> sortedAttributeList(@Nullable NamedNodeMap attrMap) {
List<Attr> list = new ArrayList<Attr>();
if (attrMap != null) {
for (int i = 0; i < attrMap.getLength(); i++) {
Node attr = attrMap.item(i);
if (attr instanceof Attr) {
list.add((Attr) attr);
}
}
}
if (list.size() > 1) {
// Sort it by attribute name
Collections.sort(list, getAttrComparator());
}
return list;
}
/**
* Returns a comparator for {@link org.w3c.dom.Attr}, alphabetically sorted by name.
* The "name" attribute is special and always sorted to the front.
*/
@NonNull
public static Comparator<? super Attr> getAttrComparator() {
return new Comparator<Attr>() {
@Override
public int compare(Attr a1, Attr a2) {
String s1 = a1 == null ? "" : a1.getNodeName(); //$NON-NLS-1$
String s2 = a2 == null ? "" : a2.getNodeValue(); //$NON-NLS-1$
int prio1 = s1.equals("name") ? 0 : 1; //$NON-NLS-1$
int prio2 = s2.equals("name") ? 0 : 1; //$NON-NLS-1$
if (prio1 == 0 || prio2 == 0) {
return prio1 - prio2;
}
return s1.compareTo(s2);
}
};
}
}