Converts the given JSON string into a List. - Android File Input Output

Android examples for File Input Output:Json String

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Description

Converts the given JSON string into a List.

Demo Code

/*//from w w w  .  ja va 2 s .  com
 * The MIT License (MIT)
 *
 * Copyright (c) 2014 Segment, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
import android.util.JsonReader;
import android.util.JsonToken;
import android.util.JsonWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import static com.segment.analytics.Utils.createMap;
import static com.segment.analytics.Utils.isNullOrEmpty;

public class Main{
    /** Converts the given string into a List. */
    static List<Object> jsonToList(String json) throws IOException {
        if (isNullOrEmpty(json)) {
            throw new IllegalArgumentException(
                    "Json must not be null or empty.");
        }
        JsonReader jsonReader = new JsonReader(new InputStreamReader(
                new ByteArrayInputStream(json.getBytes())));
        return readerToList(jsonReader);
    }
    /** Parse a json reader into a list. */
    private static List<Object> readerToList(JsonReader reader)
            throws IOException {
        List<Object> list = Collections
                .synchronizedList(new ArrayList<Object>());
        reader.beginArray();
        while (reader.hasNext()) {
            Object value = readValue(reader);
            list.add(value);
        }
        reader.endArray();
        return list;
    }
    private static Object readValue(JsonReader reader) throws IOException {
        JsonToken token = reader.peek();
        switch (token) {
        case BEGIN_OBJECT:
            return readerToMap(reader);
        case BEGIN_ARRAY:
            return readerToList(reader);
        case NUMBER:
            return reader.nextDouble();
        case STRING:
            return reader.nextString();
        case BOOLEAN:
            return reader.nextBoolean();
        case NULL:
            reader.nextNull();
            return null;
        default:
            throw new IllegalStateException("Got token " + token);
        }
    }
    /** Parse a json reader into a map. */
    private static Map<String, Object> readerToMap(JsonReader reader)
            throws IOException {
        Map<String, Object> map = createMap();
        reader.beginObject();
        while (reader.hasNext()) {
            String key = reader.nextName();
            map.put(key, readValue(reader));
        }
        reader.endObject();
        return map;
    }
}

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