de.cgarbs.lib.json.type.JSONType.java Source code

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Here is the source code for de.cgarbs.lib.json.type.JSONType.java

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/*
 * Copyright 2015 (C)  Christian Garbs <mitch@cgarbs.de>
 * Licensed under GNU GPL 3 (or later)
 */
package de.cgarbs.lib.json.type;

import java.util.LinkedHashMap;
import java.util.Map;

import org.json.simple.JSONAware;
import org.json.simple.JSONValue;

/**
 * Base class for JSON type conversion.
 * This mainly adds some metadata for later
 * retrieval of data (from JSON to Java Objects).
 *
 * @author Christian Garbs <mitch@cgarbs.de>
 * @since 0.3.0
 */
public abstract class JSONType implements JSONAware {
    static final String CLASS_FIELD = "class";
    static final String VERSION_FIELD = "version";
    static final String ATTRIBUTE_FIELD = "attributes";

    @Override
    public String toJSONString() {
        final Map<String, Object> json = new LinkedHashMap<String, Object>();
        json.put(CLASS_FIELD, getJSONClassName());
        json.put(VERSION_FIELD, getJSONClassVersion());
        json.put(ATTRIBUTE_FIELD, getJSONAttributes());
        return JSONValue.toJSONString(json);
    }

    /**
     * returns the value as the specific Java class
     * @return the value as a specific Java class
     */
    public abstract Object toJavaValue();

    /**
     * Returns a Map representation of the Object's attributes
     *
     * @return Map representation of the Object's attributes
     */
    abstract Map<String, Object> getJSONAttributes();

    /**
     * Returns the class name of the actual wrapper class.
     * Must be unique to that the class can be identified
     * when transforming from JSON back to the original Object.
     *
     * @return class name of the actual wrapper class
     */
    abstract String getJSONClassName();

    /**
     * Returns the version of the actual wrapper class.
     * Might come in handy when there are incompatible
     * changes in the wrapper classes.
     *
     * @return version of the actual wrapper class
     */
    abstract String getJSONClassVersion();
}