android-34/com/android/settingslib/license/LicenseHtmlGeneratorFromXml.java - platform/prebuilts/fullsdk/sources - Git at Google

 /*
  * Copyright (C) 2017 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.settingslib.license;

 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Xml;

 import androidx.annotation.VisibleForTesting;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.zip.GZIPInputStream;

 /**
  * The utility class that generate a license html file from xml files.
  * All the HTML snippets and logic are copied from build/make/tools/generate-notice-files.py.
  *
  * TODO: Remove duplicate codes once backward support ends.
  */
 class LicenseHtmlGeneratorFromXml {
     private static final String TAG = "LicenseGeneratorFromXml";

     private static final String TAG_ROOT = "licenses";
     private static final String TAG_FILE_NAME = "file-name";
     private static final String TAG_FILE_CONTENT = "file-content";
     private static final String ATTR_CONTENT_ID = "contentId";
     private static final String ATTR_LIBRARY_NAME = "lib";

     private static final String HTML_HEAD_STRING =
             "<html><head>\n"
             + "<style type=\"text/css\">\n"
             + "body { padding: 0; font-family: sans-serif; }\n"
             + ".same-license { background-color: #eeeeee;\n"
             + "                border-top: 20px solid white;\n"
             + "                padding: 10px; }\n"
             + ".label { font-weight: bold; }\n"
             + ".file-list { margin-left: 1em; color: blue; }\n"
             + "</style>\n"
             + "</head>"
             + "<body topmargin=\"0\" leftmargin=\"0\" rightmargin=\"0\" bottommargin=\"0\">\n"
             + "<div class=\"toc\">";
     private static final String LIBRARY_HEAD_STRING =
             "<strong>Libraries</strong>\n<ul class=\"libraries\">";
     private static final String LIBRARY_TAIL_STRING = "</ul>\n<strong>Files</strong>";

     private static final String FILES_HEAD_STRING = "<ul class=\"files\">";
     private static final String FILES_TAIL_STRING = "</ul>\n</div><!-- table of contents -->";

     private static final String CONTENT_HEAD_STRING =
             "<table cellpadding=\"0\" cellspacing=\"0\" border=\"0\">";
     private static final String CONTENT_TAIL_STRING = "</table>";

     private static final String IMAGES_HEAD_STRING =
             "<div class=\"images-list\"><strong>Images</strong>\n<ul class=\"images\">";
     private static final String IMAGES_TAIL_STRING = "</ul></div>\n";

     private static final String PATH_COUNTS_HEAD_STRING =
             "<div class=\"path-counts\"><table>\n  <tr><th>Path prefix</th><th>Count</th></tr>\n";
     private static final String PATH_COUNTS_TAIL_STRING = "</table></div>\n";

     private static final String HTML_TAIL_STRING =
             "</body></html>";

     private final List<File> mXmlFiles;

     /*
      * A map from a file name to a library name (may be empty) to a content id (MD5 sum of file
      * content) for its license.
      * For example, "/system/priv-app/TeleService/TeleService.apk" maps to "service/Telephony" to
      * "9645f39e9db895a4aa6e02cb57294595". Here "9645f39e9db895a4aa6e02cb57294595" is a MD5 sum
      * of the content of packages/services/Telephony/MODULE_LICENSE_APACHE2.
      */
     private final Map<String, Map<String, Set<String>>> mFileNameToLibraryToContentIdMap =
             new HashMap();

     /*
      * A map from a content id (MD5 sum of file content) to a license file content.
      * For example, "9645f39e9db895a4aa6e02cb57294595" maps to the content string of
      * packages/services/Telephony/MODULE_LICENSE_APACHE2. Here "9645f39e9db895a4aa6e02cb57294595"
      * is a MD5 sum of the file content.
      */
     private final Map<String, String> mContentIdToFileContentMap = new HashMap();

     static class ContentIdAndFileNames {
         final String mContentId;
         final Map<String, List<String>> mLibraryToFileNameMap = new TreeMap();

         ContentIdAndFileNames(String contentId) {
             mContentId = contentId;
         }
     }

     private LicenseHtmlGeneratorFromXml(List<File> xmlFiles) {
         mXmlFiles = xmlFiles;
     }

     public static boolean generateHtml(List<File> xmlFiles, File outputFile,
             String noticeHeader) {
         LicenseHtmlGeneratorFromXml genertor = new LicenseHtmlGeneratorFromXml(xmlFiles);
         return genertor.generateHtml(outputFile, noticeHeader);
     }

     private boolean generateHtml(File outputFile, String noticeHeader) {
         for (File xmlFile : mXmlFiles) {
             parse(xmlFile);
         }

         if (mFileNameToLibraryToContentIdMap.isEmpty() || mContentIdToFileContentMap.isEmpty()) {
             return false;
         }

         PrintWriter writer = null;
         try {
             writer = new PrintWriter(outputFile);

             generateHtml(mXmlFiles, mFileNameToLibraryToContentIdMap, mContentIdToFileContentMap,
                     writer, noticeHeader);

             writer.flush();
             writer.close();
             return true;
         } catch (IOException | SecurityException e) {
             Log.e(TAG, "Failed to generate " + outputFile, e);

             if (writer != null) {
                 writer.close();
             }
             return false;
         }
     }

     private void parse(File xmlFile) {
         if (xmlFile == null || !xmlFile.exists() || xmlFile.length() == 0) {
             return;
         }

         InputStreamReader in = null;
         try {
             if (xmlFile.getName().endsWith(".gz")) {
                 in = new InputStreamReader(new GZIPInputStream(new FileInputStream(xmlFile)));
             } else {
                 in = new FileReader(xmlFile);
             }

             parse(in, mFileNameToLibraryToContentIdMap, mContentIdToFileContentMap);

             in.close();
         } catch (XmlPullParserException | IOException e) {
             Log.e(TAG, "Failed to parse " + xmlFile, e);
             if (in != null) {
                 try {
                     in.close();
                 } catch (IOException ie) {
                     Log.w(TAG, "Failed to close " + xmlFile);
                 }
             }
         }
     }

     /*
      * Parses an input stream and fills a map from a file name to a content id for its license
      * and a map from a content id to a license file content.
      *
      * Following xml format is expected from the input stream.
      *
      *     <licenses>
      *     <file-name contentId="content_id_of_license1">file1</file-name>
      *     <file-name contentId="content_id_of_license2" lib="name of library">file2</file-name>
      *     <file-name contentId="content_id_of_license2" lib="another library">file2</file-name>
      *     ...
      *     <file-content contentId="content_id_of_license1">license1 file contents</file-content>
      *     <file-content contentId="content_id_of_license2">license2 file contents</file-content>
      *     ...
      *     </licenses>
      */
     @VisibleForTesting
     static void parse(InputStreamReader in,
             Map<String, Map<String, Set<String>>> outFileNameToLibraryToContentIdMap,
             Map<String, String> outContentIdToFileContentMap)
                     throws XmlPullParserException, IOException {
         Map<String, Map<String, Set<String>>> fileNameToLibraryToContentIdMap =
                 new HashMap<String, Map<String, Set<String>>>();
         Map<String, String> contentIdToFileContentMap = new HashMap<String, String>();

         XmlPullParser parser = Xml.newPullParser();
         parser.setInput(in);
         parser.nextTag();

         parser.require(XmlPullParser.START_TAG, "", TAG_ROOT);

         int state = parser.getEventType();
         while (state != XmlPullParser.END_DOCUMENT) {
             if (state == XmlPullParser.START_TAG) {
                 if (TAG_FILE_NAME.equals(parser.getName())) {
                     String contentId = parser.getAttributeValue("", ATTR_CONTENT_ID);
                     String libraryName = parser.getAttributeValue("", ATTR_LIBRARY_NAME);
                     if (!TextUtils.isEmpty(contentId)) {
                         String fileName = readText(parser).trim();
                         if (!TextUtils.isEmpty(fileName)) {
                             Map<String, Set<String>> libs =
                                     fileNameToLibraryToContentIdMap.computeIfAbsent(
                                             fileName, k -> new HashMap<>());
                             Set<String> contentIds = libs.computeIfAbsent(
                                             libraryName, k -> new HashSet<>());
                             contentIds.add(contentId);
                         }
                     }
                 } else if (TAG_FILE_CONTENT.equals(parser.getName())) {
                     String contentId = parser.getAttributeValue("", ATTR_CONTENT_ID);
                     if (!TextUtils.isEmpty(contentId)
                             && !outContentIdToFileContentMap.containsKey(contentId)
                             && !contentIdToFileContentMap.containsKey(contentId)) {
                         String fileContent = readText(parser);
                         if (!TextUtils.isEmpty(fileContent)) {
                             contentIdToFileContentMap.put(contentId, fileContent);
                         }
                     }
                 }
             }

             state = parser.next();
         }
         for (Map.Entry<String, Map<String, Set<String>>> mapEntry :
                 fileNameToLibraryToContentIdMap.entrySet()) {
             outFileNameToLibraryToContentIdMap.merge(
                     mapEntry.getKey(), mapEntry.getValue(), (m1, m2) -> {
                         for (Map.Entry<String, Set<String>> entry : m2.entrySet()) {
                             m1.merge(entry.getKey(), entry.getValue(), (s1, s2) -> {
                                 s1.addAll(s2);
                                 return s1;
                             });
                         }
                         return m1;
                     });
         }
         outContentIdToFileContentMap.putAll(contentIdToFileContentMap);
     }

     private static String readText(XmlPullParser parser)
             throws IOException, XmlPullParserException {
         StringBuffer result = new StringBuffer();
         int state = parser.next();
         while (state == XmlPullParser.TEXT) {
             result.append(parser.getText());
             state = parser.next();
         }
         return result.toString();
     }

     private static String pathPrefix(String path) {
         String prefix = path;
         while (prefix.length() > 0 && prefix.substring(0, 1).equals("/")) {
             prefix = prefix.substring(1);
         }
         int idx = prefix.indexOf("/");
         if (idx > 0) {
             prefix = prefix.substring(0, idx);
         }
         return prefix;
     }

     @VisibleForTesting
     static void generateHtml(List<File> xmlFiles,
             Map<String, Map<String, Set<String>>> fileNameToLibraryToContentIdMap,
             Map<String, String> contentIdToFileContentMap, PrintWriter writer,
             String noticeHeader) throws IOException {
         List<String> fileNameList = new ArrayList();
         fileNameList.addAll(fileNameToLibraryToContentIdMap.keySet());
         Collections.sort(fileNameList);

         SortedMap<String, Integer> prefixToCount = new TreeMap();
         for (String f : fileNameList) {
             String prefix = pathPrefix(f);
             prefixToCount.merge(prefix, 1, Integer::sum);
         }

         SortedMap<String, Set<String>> libraryToContentIdMap = new TreeMap();
         for (Map<String, Set<String>> libraryToContentValue :
                 fileNameToLibraryToContentIdMap.values()) {
             for (Map.Entry<String, Set<String>> entry : libraryToContentValue.entrySet()) {
                 if (TextUtils.isEmpty(entry.getKey())) {
                     continue;
                 }
                 libraryToContentIdMap.merge(
                         entry.getKey(), entry.getValue(), (s1, s2) -> {
                             s1.addAll(s2);
                             return s1;
                         });
             }
         }

         writer.println(HTML_HEAD_STRING);

         if (!TextUtils.isEmpty(noticeHeader)) {
             writer.println(noticeHeader);
         }

         int count = 0;
         Map<String, Integer> contentIdToOrderMap = new HashMap();
         List<ContentIdAndFileNames> contentIdAndFileNamesList = new ArrayList();

         if (!libraryToContentIdMap.isEmpty()) {
             writer.println(LIBRARY_HEAD_STRING);
             for (Map.Entry<String, Set<String>> entry: libraryToContentIdMap.entrySet()) {
                 String libraryName = entry.getKey();
                 for (String contentId : entry.getValue()) {
                     // Assigns an id to a newly referred license file content.
                     if (!contentIdToOrderMap.containsKey(contentId)) {
                         contentIdToOrderMap.put(contentId, count);

                         // An index in contentIdAndFileNamesList is the order of each element.
                         contentIdAndFileNamesList.add(new ContentIdAndFileNames(contentId));
                         count++;
                     }
                     int id = contentIdToOrderMap.get(contentId);
                     writer.format("<li><a href=\"#id%d\">%s</a></li>\n", id, libraryName);
                 }
             }
             writer.println(LIBRARY_TAIL_STRING);
         }

         if (!fileNameList.isEmpty()) {
             writer.println(FILES_HEAD_STRING);
             // Prints all the file list with a link to its license file content.
             for (String fileName : fileNameList) {
                 for (Map.Entry<String, Set<String>> libToContentId :
                         fileNameToLibraryToContentIdMap.get(fileName).entrySet()) {
                     String libraryName = libToContentId.getKey();
                     if (libraryName == null) {
                         libraryName = "";
                     }
                     for (String contentId : libToContentId.getValue()) {
                         // Assigns an id to a newly referred license file content.
                         if (!contentIdToOrderMap.containsKey(contentId)) {
                             contentIdToOrderMap.put(contentId, count);

                             // An index in contentIdAndFileNamesList is the order of each element.
                             contentIdAndFileNamesList.add(new ContentIdAndFileNames(contentId));
                             count++;
                         }

                         int id = contentIdToOrderMap.get(contentId);
                         ContentIdAndFileNames elem = contentIdAndFileNamesList.get(id);
                         List<String> files = elem.mLibraryToFileNameMap.computeIfAbsent(
                                 libraryName, k -> new ArrayList());
                         files.add(fileName);
                         if (TextUtils.isEmpty(libraryName)) {
                             writer.format("<li><a href=\"#id%d\">%s</a></li>\n", id, fileName);
                         } else {
                             writer.format("<li><a href=\"#id%d\">%s - %s</a></li>\n",
                                     id, fileName, libraryName);
                         }
                     }
                 }
             }
             writer.println(FILES_TAIL_STRING);
         }

         if (!contentIdAndFileNamesList.isEmpty()) {
             writer.println(CONTENT_HEAD_STRING);
             // Prints all contents of the license files in order of id.
             for (ContentIdAndFileNames contentIdAndFileNames : contentIdAndFileNamesList) {
                 // Assigns an id to a newly referred license file content (should never happen here)
                 if (!contentIdToOrderMap.containsKey(contentIdAndFileNames.mContentId)) {
                     contentIdToOrderMap.put(contentIdAndFileNames.mContentId, count);
                     count++;
                 }
                 int id = contentIdToOrderMap.get(contentIdAndFileNames.mContentId);
                 writer.format("<tr id=\"id%d\"><td class=\"same-license\">\n", id);
                 for (Map.Entry<String, List<String>> libraryFiles :
                         contentIdAndFileNames.mLibraryToFileNameMap.entrySet()) {
                     String libraryName = libraryFiles.getKey();
                     if (TextUtils.isEmpty(libraryName)) {
                         writer.println("<div class=\"label\">Notices for file(s):</div>");
                     } else {
                         writer.format("<div class=\"label\"><strong>%s</strong> used by:</div>\n",
                                 libraryName);
                     }
                     writer.println("<div class=\"file-list\">");
                     for (String fileName : libraryFiles.getValue()) {
                         writer.format("%s <br/>\n", fileName);
                     }
                     writer.println("</div><!-- file-list -->");
                 }
                 writer.println("<pre class=\"license-text\">");
                 writer.println(contentIdToFileContentMap.get(
                         contentIdAndFileNames.mContentId));
                 writer.println("</pre><!-- license-text -->");
                 writer.println("</td></tr><!-- same-license -->");
             }
             writer.println(CONTENT_TAIL_STRING);
         }

         if (!xmlFiles.isEmpty()) {
             writer.println(IMAGES_HEAD_STRING);
             for (File file : xmlFiles) {
                 writer.format("  <li>%s</li>\n", pathPrefix(file.getCanonicalPath()));
             }
             writer.println(IMAGES_TAIL_STRING);
         }

         if (!prefixToCount.isEmpty()) {
             writer.println(PATH_COUNTS_HEAD_STRING);
             for (Map.Entry<String, Integer> entry : prefixToCount.entrySet()) {
                 writer.format("  <tr><td>%s</td><td>%d</td></tr>\n",
                         entry.getKey(), entry.getValue());
             }
             writer.println(PATH_COUNTS_TAIL_STRING);
         }

         writer.println(HTML_TAIL_STRING);
     }
 }
	/*
	* Copyright (C) 2017 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.settingslib.license;

	import android.text.TextUtils;
	import android.util.Log;
	import android.util.Xml;

	import androidx.annotation.VisibleForTesting;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlPullParserException;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileReader;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.io.PrintWriter;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.SortedMap;
	import java.util.TreeMap;
	import java.util.zip.GZIPInputStream;

	/**
	* The utility class that generate a license html file from xml files.
	* All the HTML snippets and logic are copied from build/make/tools/generate-notice-files.py.
	*
	* TODO: Remove duplicate codes once backward support ends.
	*/
	class LicenseHtmlGeneratorFromXml {
	private static final String TAG = "LicenseGeneratorFromXml";

	private static final String TAG_ROOT = "licenses";
	private static final String TAG_FILE_NAME = "file-name";
	private static final String TAG_FILE_CONTENT = "file-content";
	private static final String ATTR_CONTENT_ID = "contentId";
	private static final String ATTR_LIBRARY_NAME = "lib";

	private static final String HTML_HEAD_STRING =
	"<html><head>\n"
	+ "<style type=\"text/css\">\n"
	+ "body { padding: 0; font-family: sans-serif; }\n"
	+ ".same-license { background-color: #eeeeee;\n"
	+ " border-top: 20px solid white;\n"
	+ " padding: 10px; }\n"
	+ ".label { font-weight: bold; }\n"
	+ ".file-list { margin-left: 1em; color: blue; }\n"
	+ "</style>\n"
	+ "</head>"
	+ "<body topmargin=\"0\" leftmargin=\"0\" rightmargin=\"0\" bottommargin=\"0\">\n"
	+ "<div class=\"toc\">";
	private static final String LIBRARY_HEAD_STRING =
	"<strong>Libraries</strong>\n<ul class=\"libraries\">";
	private static final String LIBRARY_TAIL_STRING = "</ul>\n<strong>Files</strong>";

	private static final String FILES_HEAD_STRING = "<ul class=\"files\">";
	private static final String FILES_TAIL_STRING = "</ul>\n</div><!-- table of contents -->";

	private static final String CONTENT_HEAD_STRING =
	"<table cellpadding=\"0\" cellspacing=\"0\" border=\"0\">";
	private static final String CONTENT_TAIL_STRING = "</table>";

	private static final String IMAGES_HEAD_STRING =
	"<div class=\"images-list\"><strong>Images</strong>\n<ul class=\"images\">";
	private static final String IMAGES_TAIL_STRING = "</ul></div>\n";

	private static final String PATH_COUNTS_HEAD_STRING =
	"<div class=\"path-counts\"><table>\n <tr><th>Path prefix</th><th>Count</th></tr>\n";
	private static final String PATH_COUNTS_TAIL_STRING = "</table></div>\n";

	private static final String HTML_TAIL_STRING =
	"</body></html>";

	private final List<File> mXmlFiles;

	/*
	* A map from a file name to a library name (may be empty) to a content id (MD5 sum of file
	* content) for its license.
	* For example, "/system/priv-app/TeleService/TeleService.apk" maps to "service/Telephony" to
	* "9645f39e9db895a4aa6e02cb57294595". Here "9645f39e9db895a4aa6e02cb57294595" is a MD5 sum
	* of the content of packages/services/Telephony/MODULE_LICENSE_APACHE2.
	*/
	private final Map<String, Map<String, Set<String>>> mFileNameToLibraryToContentIdMap =
	new HashMap();

	/*
	* A map from a content id (MD5 sum of file content) to a license file content.
	* For example, "9645f39e9db895a4aa6e02cb57294595" maps to the content string of
	* packages/services/Telephony/MODULE_LICENSE_APACHE2. Here "9645f39e9db895a4aa6e02cb57294595"
	* is a MD5 sum of the file content.
	*/
	private final Map<String, String> mContentIdToFileContentMap = new HashMap();

	static class ContentIdAndFileNames {
	final String mContentId;
	final Map<String, List<String>> mLibraryToFileNameMap = new TreeMap();

	ContentIdAndFileNames(String contentId) {
	mContentId = contentId;
	}
	}

	private LicenseHtmlGeneratorFromXml(List<File> xmlFiles) {
	mXmlFiles = xmlFiles;
	}

	public static boolean generateHtml(List<File> xmlFiles, File outputFile,
	String noticeHeader) {
	LicenseHtmlGeneratorFromXml genertor = new LicenseHtmlGeneratorFromXml(xmlFiles);
	return genertor.generateHtml(outputFile, noticeHeader);
	}

	private boolean generateHtml(File outputFile, String noticeHeader) {
	for (File xmlFile : mXmlFiles) {
	parse(xmlFile);
	}

	if (mFileNameToLibraryToContentIdMap.isEmpty() \|\| mContentIdToFileContentMap.isEmpty()) {
	return false;
	}

	PrintWriter writer = null;
	try {
	writer = new PrintWriter(outputFile);

	generateHtml(mXmlFiles, mFileNameToLibraryToContentIdMap, mContentIdToFileContentMap,
	writer, noticeHeader);

	writer.flush();
	writer.close();
	return true;
	} catch (IOException \| SecurityException e) {
	Log.e(TAG, "Failed to generate " + outputFile, e);

	if (writer != null) {
	writer.close();
	}
	return false;
	}
	}

	private void parse(File xmlFile) {
	if (xmlFile == null \|\| !xmlFile.exists() \|\| xmlFile.length() == 0) {
	return;
	}

	InputStreamReader in = null;
	try {
	if (xmlFile.getName().endsWith(".gz")) {
	in = new InputStreamReader(new GZIPInputStream(new FileInputStream(xmlFile)));
	} else {
	in = new FileReader(xmlFile);
	}

	parse(in, mFileNameToLibraryToContentIdMap, mContentIdToFileContentMap);

	in.close();
	} catch (XmlPullParserException \| IOException e) {
	Log.e(TAG, "Failed to parse " + xmlFile, e);
	if (in != null) {
	try {
	in.close();
	} catch (IOException ie) {
	Log.w(TAG, "Failed to close " + xmlFile);
	}
	}
	}
	}

	/*
	* Parses an input stream and fills a map from a file name to a content id for its license
	* and a map from a content id to a license file content.
	*
	* Following xml format is expected from the input stream.
	*
	* <licenses>
	* <file-name contentId="content_id_of_license1">file1</file-name>
	* <file-name contentId="content_id_of_license2" lib="name of library">file2</file-name>
	* <file-name contentId="content_id_of_license2" lib="another library">file2</file-name>
	* ...
	* <file-content contentId="content_id_of_license1">license1 file contents</file-content>
	* <file-content contentId="content_id_of_license2">license2 file contents</file-content>
	* ...
	* </licenses>
	*/
	@VisibleForTesting
	static void parse(InputStreamReader in,
	Map<String, Map<String, Set<String>>> outFileNameToLibraryToContentIdMap,
	Map<String, String> outContentIdToFileContentMap)
	throws XmlPullParserException, IOException {
	Map<String, Map<String, Set<String>>> fileNameToLibraryToContentIdMap =
	new HashMap<String, Map<String, Set<String>>>();
	Map<String, String> contentIdToFileContentMap = new HashMap<String, String>();

	XmlPullParser parser = Xml.newPullParser();
	parser.setInput(in);
	parser.nextTag();

	parser.require(XmlPullParser.START_TAG, "", TAG_ROOT);

	int state = parser.getEventType();
	while (state != XmlPullParser.END_DOCUMENT) {
	if (state == XmlPullParser.START_TAG) {
	if (TAG_FILE_NAME.equals(parser.getName())) {
	String contentId = parser.getAttributeValue("", ATTR_CONTENT_ID);
	String libraryName = parser.getAttributeValue("", ATTR_LIBRARY_NAME);
	if (!TextUtils.isEmpty(contentId)) {
	String fileName = readText(parser).trim();
	if (!TextUtils.isEmpty(fileName)) {
	Map<String, Set<String>> libs =
	fileNameToLibraryToContentIdMap.computeIfAbsent(
	fileName, k -> new HashMap<>());
	Set<String> contentIds = libs.computeIfAbsent(
	libraryName, k -> new HashSet<>());
	contentIds.add(contentId);
	}
	}
	} else if (TAG_FILE_CONTENT.equals(parser.getName())) {
	String contentId = parser.getAttributeValue("", ATTR_CONTENT_ID);
	if (!TextUtils.isEmpty(contentId)
	&& !outContentIdToFileContentMap.containsKey(contentId)
	&& !contentIdToFileContentMap.containsKey(contentId)) {
	String fileContent = readText(parser);
	if (!TextUtils.isEmpty(fileContent)) {
	contentIdToFileContentMap.put(contentId, fileContent);
	}
	}
	}
	}

	state = parser.next();
	}
	for (Map.Entry<String, Map<String, Set<String>>> mapEntry :
	fileNameToLibraryToContentIdMap.entrySet()) {
	outFileNameToLibraryToContentIdMap.merge(
	mapEntry.getKey(), mapEntry.getValue(), (m1, m2) -> {
	for (Map.Entry<String, Set<String>> entry : m2.entrySet()) {
	m1.merge(entry.getKey(), entry.getValue(), (s1, s2) -> {
	s1.addAll(s2);
	return s1;
	});
	}
	return m1;
	});
	}
	outContentIdToFileContentMap.putAll(contentIdToFileContentMap);
	}

	private static String readText(XmlPullParser parser)
	throws IOException, XmlPullParserException {
	StringBuffer result = new StringBuffer();
	int state = parser.next();
	while (state == XmlPullParser.TEXT) {
	result.append(parser.getText());
	state = parser.next();
	}
	return result.toString();
	}

	private static String pathPrefix(String path) {
	String prefix = path;
	while (prefix.length() > 0 && prefix.substring(0, 1).equals("/")) {
	prefix = prefix.substring(1);
	}
	int idx = prefix.indexOf("/");
	if (idx > 0) {
	prefix = prefix.substring(0, idx);
	}
	return prefix;
	}

	@VisibleForTesting
	static void generateHtml(List<File> xmlFiles,
	Map<String, Map<String, Set<String>>> fileNameToLibraryToContentIdMap,
	Map<String, String> contentIdToFileContentMap, PrintWriter writer,
	String noticeHeader) throws IOException {
	List<String> fileNameList = new ArrayList();
	fileNameList.addAll(fileNameToLibraryToContentIdMap.keySet());
	Collections.sort(fileNameList);

	SortedMap<String, Integer> prefixToCount = new TreeMap();
	for (String f : fileNameList) {
	String prefix = pathPrefix(f);
	prefixToCount.merge(prefix, 1, Integer::sum);
	}

	SortedMap<String, Set<String>> libraryToContentIdMap = new TreeMap();
	for (Map<String, Set<String>> libraryToContentValue :
	fileNameToLibraryToContentIdMap.values()) {
	for (Map.Entry<String, Set<String>> entry : libraryToContentValue.entrySet()) {
	if (TextUtils.isEmpty(entry.getKey())) {
	continue;
	}
	libraryToContentIdMap.merge(
	entry.getKey(), entry.getValue(), (s1, s2) -> {
	s1.addAll(s2);
	return s1;
	});
	}
	}

	writer.println(HTML_HEAD_STRING);

	if (!TextUtils.isEmpty(noticeHeader)) {
	writer.println(noticeHeader);
	}

	int count = 0;
	Map<String, Integer> contentIdToOrderMap = new HashMap();
	List<ContentIdAndFileNames> contentIdAndFileNamesList = new ArrayList();

	if (!libraryToContentIdMap.isEmpty()) {
	writer.println(LIBRARY_HEAD_STRING);
	for (Map.Entry<String, Set<String>> entry: libraryToContentIdMap.entrySet()) {
	String libraryName = entry.getKey();
	for (String contentId : entry.getValue()) {
	// Assigns an id to a newly referred license file content.
	if (!contentIdToOrderMap.containsKey(contentId)) {
	contentIdToOrderMap.put(contentId, count);

	// An index in contentIdAndFileNamesList is the order of each element.
	contentIdAndFileNamesList.add(new ContentIdAndFileNames(contentId));
	count++;
	}
	int id = contentIdToOrderMap.get(contentId);
	writer.format("<li><a href=\"#id%d\">%s</a></li>\n", id, libraryName);
	}
	}
	writer.println(LIBRARY_TAIL_STRING);
	}

	if (!fileNameList.isEmpty()) {
	writer.println(FILES_HEAD_STRING);
	// Prints all the file list with a link to its license file content.
	for (String fileName : fileNameList) {
	for (Map.Entry<String, Set<String>> libToContentId :
	fileNameToLibraryToContentIdMap.get(fileName).entrySet()) {
	String libraryName = libToContentId.getKey();
	if (libraryName == null) {
	libraryName = "";
	}
	for (String contentId : libToContentId.getValue()) {
	// Assigns an id to a newly referred license file content.
	if (!contentIdToOrderMap.containsKey(contentId)) {
	contentIdToOrderMap.put(contentId, count);

	// An index in contentIdAndFileNamesList is the order of each element.
	contentIdAndFileNamesList.add(new ContentIdAndFileNames(contentId));
	count++;
	}

	int id = contentIdToOrderMap.get(contentId);
	ContentIdAndFileNames elem = contentIdAndFileNamesList.get(id);
	List<String> files = elem.mLibraryToFileNameMap.computeIfAbsent(
	libraryName, k -> new ArrayList());
	files.add(fileName);
	if (TextUtils.isEmpty(libraryName)) {
	writer.format("<li><a href=\"#id%d\">%s</a></li>\n", id, fileName);
	} else {
	writer.format("<li><a href=\"#id%d\">%s - %s</a></li>\n",
	id, fileName, libraryName);
	}
	}
	}
	}
	writer.println(FILES_TAIL_STRING);
	}

	if (!contentIdAndFileNamesList.isEmpty()) {
	writer.println(CONTENT_HEAD_STRING);
	// Prints all contents of the license files in order of id.
	for (ContentIdAndFileNames contentIdAndFileNames : contentIdAndFileNamesList) {
	// Assigns an id to a newly referred license file content (should never happen here)
	if (!contentIdToOrderMap.containsKey(contentIdAndFileNames.mContentId)) {
	contentIdToOrderMap.put(contentIdAndFileNames.mContentId, count);
	count++;
	}
	int id = contentIdToOrderMap.get(contentIdAndFileNames.mContentId);
	writer.format("<tr id=\"id%d\"><td class=\"same-license\">\n", id);
	for (Map.Entry<String, List<String>> libraryFiles :
	contentIdAndFileNames.mLibraryToFileNameMap.entrySet()) {
	String libraryName = libraryFiles.getKey();
	if (TextUtils.isEmpty(libraryName)) {
	writer.println("<div class=\"label\">Notices for file(s):</div>");
	} else {
	writer.format("<div class=\"label\"><strong>%s</strong> used by:</div>\n",
	libraryName);
	}
	writer.println("<div class=\"file-list\">");
	for (String fileName : libraryFiles.getValue()) {
	writer.format("%s <br/>\n", fileName);
	}
	writer.println("</div><!-- file-list -->");
	}
	writer.println("<pre class=\"license-text\">");
	writer.println(contentIdToFileContentMap.get(
	contentIdAndFileNames.mContentId));
	writer.println("</pre><!-- license-text -->");
	writer.println("</td></tr><!-- same-license -->");
	}
	writer.println(CONTENT_TAIL_STRING);
	}

	if (!xmlFiles.isEmpty()) {
	writer.println(IMAGES_HEAD_STRING);
	for (File file : xmlFiles) {
	writer.format(" <li>%s</li>\n", pathPrefix(file.getCanonicalPath()));
	}
	writer.println(IMAGES_TAIL_STRING);
	}

	if (!prefixToCount.isEmpty()) {
	writer.println(PATH_COUNTS_HEAD_STRING);
	for (Map.Entry<String, Integer> entry : prefixToCount.entrySet()) {
	writer.format(" <tr><td>%s</td><td>%d</td></tr>\n",
	entry.getKey(), entry.getValue());
	}
	writer.println(PATH_COUNTS_TAIL_STRING);
	}

	writer.println(HTML_TAIL_STRING);
	}
	}