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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
      5  * use this file except in compliance with the License. You may obtain a copy of
      6  * the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
     12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     13  * License for the specific language governing permissions and limitations under
     14  * the License.
     15  */
     16 
     17 package com.android.inputmethod.dictionarypack;
     18 
     19 import android.text.TextUtils;
     20 import android.util.JsonReader;
     21 
     22 import java.io.IOException;
     23 import java.io.InputStreamReader;
     24 import java.util.ArrayList;
     25 import java.util.Collections;
     26 import java.util.List;
     27 import java.util.TreeMap;
     28 
     29 /**
     30  * Helper class containing functions to parse the dictionary metadata.
     31  */
     32 public class MetadataParser {
     33 
     34     // Name of the fields in the JSON-formatted file.
     35     private static final String ID_FIELD_NAME = MetadataDbHelper.WORDLISTID_COLUMN;
     36     private static final String LOCALE_FIELD_NAME = "locale";
     37     private static final String DESCRIPTION_FIELD_NAME = MetadataDbHelper.DESCRIPTION_COLUMN;
     38     private static final String UPDATE_FIELD_NAME = "update";
     39     private static final String FILESIZE_FIELD_NAME = MetadataDbHelper.FILESIZE_COLUMN;
     40     private static final String CHECKSUM_FIELD_NAME = MetadataDbHelper.CHECKSUM_COLUMN;
     41     private static final String REMOTE_FILENAME_FIELD_NAME =
     42             MetadataDbHelper.REMOTE_FILENAME_COLUMN;
     43     private static final String VERSION_FIELD_NAME = MetadataDbHelper.VERSION_COLUMN;
     44     private static final String FORMATVERSION_FIELD_NAME = MetadataDbHelper.FORMATVERSION_COLUMN;
     45 
     46     /**
     47      * Parse one JSON-formatted word list metadata.
     48      * @param reader the reader containing the data.
     49      * @return a WordListMetadata object from the parsed data.
     50      * @throws IOException if the underlying reader throws IOException during reading.
     51      */
     52     private static WordListMetadata parseOneWordList(final JsonReader reader)
     53             throws IOException, BadFormatException {
     54         final TreeMap<String, String> arguments = new TreeMap<String, String>();
     55         reader.beginObject();
     56         while (reader.hasNext()) {
     57             final String name = reader.nextName();
     58             if (!TextUtils.isEmpty(name)) {
     59                 arguments.put(name, reader.nextString());
     60             }
     61         }
     62         reader.endObject();
     63         if (TextUtils.isEmpty(arguments.get(ID_FIELD_NAME))
     64                 || TextUtils.isEmpty(arguments.get(LOCALE_FIELD_NAME))
     65                 || TextUtils.isEmpty(arguments.get(DESCRIPTION_FIELD_NAME))
     66                 || TextUtils.isEmpty(arguments.get(UPDATE_FIELD_NAME))
     67                 || TextUtils.isEmpty(arguments.get(FILESIZE_FIELD_NAME))
     68                 || TextUtils.isEmpty(arguments.get(CHECKSUM_FIELD_NAME))
     69                 || TextUtils.isEmpty(arguments.get(REMOTE_FILENAME_FIELD_NAME))
     70                 || TextUtils.isEmpty(arguments.get(VERSION_FIELD_NAME))
     71                 || TextUtils.isEmpty(arguments.get(FORMATVERSION_FIELD_NAME))) {
     72             throw new BadFormatException(arguments.toString());
     73         }
     74         // TODO: need to find out whether it's bulk or update
     75         // The null argument is the local file name, which is not known at this time and will
     76         // be decided later.
     77         return new WordListMetadata(
     78                 arguments.get(ID_FIELD_NAME),
     79                 MetadataDbHelper.TYPE_BULK,
     80                 arguments.get(DESCRIPTION_FIELD_NAME),
     81                 Long.parseLong(arguments.get(UPDATE_FIELD_NAME)),
     82                 Long.parseLong(arguments.get(FILESIZE_FIELD_NAME)),
     83                 arguments.get(CHECKSUM_FIELD_NAME),
     84                 null,
     85                 arguments.get(REMOTE_FILENAME_FIELD_NAME),
     86                 Integer.parseInt(arguments.get(VERSION_FIELD_NAME)),
     87                 Integer.parseInt(arguments.get(FORMATVERSION_FIELD_NAME)),
     88                 0, arguments.get(LOCALE_FIELD_NAME));
     89     }
     90 
     91     /**
     92      * Parses metadata in the JSON format.
     93      * @param input a stream reader expected to contain JSON formatted metadata.
     94      * @return dictionary metadata, as an array of WordListMetadata objects.
     95      * @throws IOException if the underlying reader throws IOException during reading.
     96      * @throws BadFormatException if the data was not in the expected format.
     97      */
     98     public static List<WordListMetadata> parseMetadata(final InputStreamReader input)
     99             throws IOException, BadFormatException {
    100         JsonReader reader = new JsonReader(input);
    101         final ArrayList<WordListMetadata> readInfo = new ArrayList<WordListMetadata>();
    102         reader.beginArray();
    103         while (reader.hasNext()) {
    104             final WordListMetadata thisMetadata = parseOneWordList(reader);
    105             if (!TextUtils.isEmpty(thisMetadata.mLocale))
    106                 readInfo.add(thisMetadata);
    107         }
    108         return Collections.unmodifiableList(readInfo);
    109     }
    110 
    111 }
    112