org.eclipse.packagedrone.repo.channel.impl.ChannelInstanceModelProvider.java Source code

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Here is the source code for org.eclipse.packagedrone.repo.channel.impl.ChannelInstanceModelProvider.java

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/*******************************************************************************
 * Copyright (c) 2016 IBH SYSTEMS GmbH and others.
 * 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:
 *     IBH SYSTEMS GmbH - initial API and implementation
 *******************************************************************************/
package org.eclipse.packagedrone.repo.channel.impl;

import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;

import org.eclipse.packagedrone.storage.apm.AbstractSimpleStorageModelProvider;
import org.eclipse.packagedrone.storage.apm.StorageContext;
import org.eclipse.packagedrone.storage.apm.util.ReplaceOnCloseWriter;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class ChannelInstanceModelProvider
        extends AbstractSimpleStorageModelProvider<ChannelInstanceModelAccess, ChannelInstanceModel> {
    private final String channelId;

    public ChannelInstanceModelProvider(final String channelId) {
        super(ChannelInstanceModel.class);
        this.channelId = channelId;
    }

    @Override
    protected ChannelInstanceModelAccess makeViewModelTyped(final ChannelInstanceModel writeModel) {
        return new ChannelInstanceModel(writeModel);
    }

    @Override
    protected ChannelInstanceModel cloneWriteModel(final ChannelInstanceModel writeModel) {
        return new ChannelInstanceModel(writeModel);
    }

    private static Gson createGson() {
        final GsonBuilder builder = new GsonBuilder();
        builder.setPrettyPrinting();
        builder.setDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
        return builder.create();
    }

    @Override
    protected void persistWriteModel(final StorageContext context, final ChannelInstanceModel writeModel)
            throws Exception {
        if (!writeModel.isModified()) {
            return;
        }

        final Gson gson = createGson();

        final Path path = makePath(context);
        Files.createDirectories(path.getParent());

        try (ReplaceOnCloseWriter writer = new ReplaceOnCloseWriter(path, StandardCharsets.UTF_8)) {
            gson.toJson(writeModel, writer);
            writer.commit();
        }
    }

    @Override
    protected ChannelInstanceModel loadWriteModel(final StorageContext context) throws Exception {
        final Path path = makePath(context);

        final Gson gson = createGson();
        try (Reader reader = Files.newBufferedReader(path)) {
            return gson.fromJson(reader, ChannelInstanceModel.class);
        } catch (final NoSuchFileException e) {
            return new ChannelInstanceModel(); // create a new one
        }
    }

    private Path makePath(final StorageContext context) {
        return context.getBasePath().resolve("channel.cfg").resolve(this.channelId + ".json");
    }
}