org.hibernate.search.backend.elasticsearch.gson.impl.AbstractExtraPropertiesJsonAdapter.java Source code

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Here is the source code for org.hibernate.search.backend.elasticsearch.gson.impl.AbstractExtraPropertiesJsonAdapter.java

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/*
 * Hibernate Search, full-text search for your domain model
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.search.backend.elasticsearch.gson.impl;

import java.io.IOException;
import java.util.Map;

import com.google.gson.JsonSyntaxException;
import com.google.gson.TypeAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;

/**
 * @author Yoann Rodiere
 */
public abstract class AbstractExtraPropertiesJsonAdapter<T> extends TypeAdapter<T> {

    interface FieldAdapter<T> {
        void read(JsonReader in, T instance) throws IOException;

        void write(JsonWriter out, T instance) throws IOException;

        boolean serialized();
    }

    interface ExtraPropertyAdapter<T> {
        void readOne(JsonReader in, String name, T instance) throws IOException;

        void writeAll(JsonWriter out, T instance) throws IOException;
    }

    private final Map<String, ? extends FieldAdapter<? super T>> fieldAdapters;
    private final ExtraPropertyAdapter<? super T> extraPropertyAdapter;

    public AbstractExtraPropertiesJsonAdapter(Map<String, ? extends FieldAdapter<? super T>> fieldAdapters,
            ExtraPropertyAdapter<? super T> extraPropertyAdapter) {
        super();
        this.fieldAdapters = fieldAdapters;
        this.extraPropertyAdapter = extraPropertyAdapter;
    }

    @Override
    public T read(JsonReader in) throws IOException {
        if (in.peek() == JsonToken.NULL) {
            in.nextNull();
            return null;
        }

        T instance = createInstance();
        try {
            in.beginObject();
            while (in.hasNext()) {
                String name = in.nextName();
                FieldAdapter<? super T> fieldAdapter = fieldAdapters.get(name);
                if (fieldAdapter == null) {
                    extraPropertyAdapter.readOne(in, name, instance);
                } else {
                    fieldAdapter.read(in, instance);
                }
            }
            in.endObject();
        } catch (IllegalStateException e) {
            throw new JsonSyntaxException(e);
        }

        return instance;
    }

    @Override
    public void write(JsonWriter out, T instance) throws IOException {
        if (instance == null) {
            out.nullValue();
        }
        out.beginObject();
        for (Map.Entry<String, ? extends FieldAdapter<? super T>> entry : fieldAdapters.entrySet()) {
            FieldAdapter<? super T> fieldAdapter = entry.getValue();
            if (fieldAdapter.serialized()) {
                out.name(entry.getKey());
                entry.getValue().write(out, instance);
            }
        }
        extraPropertyAdapter.writeAll(out, instance);
        out.endObject();
    }

    protected abstract T createInstance();

}