org.eclipse.recommenders.args.completion.rcp.usagedb.UsageDBJSONReader.java Source code

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Here is the source code for org.eclipse.recommenders.args.completion.rcp.usagedb.UsageDBJSONReader.java

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/**
 * Copyright (c) 2011, 2012 Shanghai Jiao Tong University.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Cheng Zhang - initial API and implementation.
 */
package org.eclipse.recommenders.args.completion.rcp.usagedb;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.google.common.io.CharStreams;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

/**
 * This class used to get param infomation from json file.
 * 
 * Note: It is different from model file. Parameter information didn't contain 
 * the model of Bayes Network. 
 * 
 * @author Tong
 *
 */
public class UsageDBJSONReader {
    /** The InputStream of the json file.    */
    private InputStream inputStream;

    /** The parameter info from json file.    */
    private Map<Integer, ParamInfo> index2param;

    /** The probability of param from json file.    */
    private Map<Integer, Integer> index2freq;

    public UsageDBJSONReader(final InputStream is) {
        this.inputStream = is;
        index2param = new HashMap<Integer, ParamInfo>();
        index2freq = new HashMap<Integer, Integer>();
    }

    public final Map<Integer, ParamInfo> getIndex2param() {
        return index2param;
    }

    public final void setIndex2param(final Map<Integer, ParamInfo> i2p) {
        this.index2param = i2p;
    }

    public final Map<Integer, Integer> getIndex2freq() {
        return index2freq;
    }

    public final void setIndex2freq(final Map<Integer, Integer> i2f) {
        this.index2freq = i2f;
    }

    /**
     * Read param info from json file.
     * 
     * Include the list of ParamInfo , and list of frequency.
     * 
     * @return "true" for success
     */
    public final boolean readMapFromJSON() {
        boolean success = false;

        String content;
        try {
            content = CharStreams.toString(new InputStreamReader(inputStream));

            //The json file contains only a list of ParamInfoToJson.
            List<ParamInfoToJson> paramInfos = (List<ParamInfoToJson>) new Gson().fromJson(content,
                    new TypeToken<List<ParamInfoToJson>>() {
                    }.getType());

            for (ParamInfoToJson p : paramInfos) {
                index2param.put(p.getIndex(), p.getParaminfo());
                index2freq.put(p.getIndex(), p.getFreq());
                success = true;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        return success;
    }
}