org.wrml.runtime.format.application.schema.json.JsonSchemaFormatter.java Source code

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Here is the source code for org.wrml.runtime.format.application.schema.json.JsonSchemaFormatter.java

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/**
 * WRML - Web Resource Modeling Language
 *  __     __   ______   __    __   __
 * /\ \  _ \ \ /\  == \ /\ "-./  \ /\ \
 * \ \ \/ ".\ \\ \  __< \ \ \-./\ \\ \ \____
 *  \ \__/".~\_\\ \_\ \_\\ \_\ \ \_\\ \_____\
 *   \/_/   \/_/ \/_/ /_/ \/_/  \/_/ \/_____/
 *
 * http://www.wrml.org
 *
 * Copyright (C) 2011 - 2013 Mark Masse <mark@wrml.org> (OSS project WRML.org)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wrml.runtime.format.application.schema.json;

import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import org.wrml.model.Model;
import org.wrml.model.schema.Schema;
import org.wrml.runtime.Context;
import org.wrml.runtime.Dimensions;
import org.wrml.runtime.Keys;
import org.wrml.runtime.format.AbstractFormatter;
import org.wrml.runtime.format.ModelReadingException;
import org.wrml.runtime.format.ModelWriteOptions;
import org.wrml.runtime.format.ModelWritingException;
import org.wrml.runtime.schema.Prototype;
import org.wrml.runtime.schema.SchemaLoader;

import java.io.InputStream;
import java.io.InvalidObjectException;
import java.io.OutputStream;
import java.net.URI;

public class JsonSchemaFormatter extends AbstractFormatter {

    public JsonSchemaFormatter() {

    }

    @Override
    public boolean isApplicableTo(final URI schemaUri) {

        if (schemaUri == null) {
            return false;
        }
        final Context context = getContext();
        final SchemaLoader schemaLoader = context.getSchemaLoader();
        final Prototype schemaPrototype = schemaLoader.getPrototype(schemaLoader.getSchemaSchemaUri());
        return (schemaPrototype.isAssignableFrom(schemaUri));
    }

    @SuppressWarnings("unchecked")
    @Override
    public <M extends Model> M readModel(final InputStream in, final Keys rootModelKeys,
            final Dimensions rootModelDimensions) throws ModelReadingException, UnsupportedOperationException {

        final Context context = getContext();
        final SchemaLoader schemaLoader = context.getSchemaLoader();

        final URI uri = rootModelKeys.getValue(schemaLoader.getDocumentSchemaUri());
        final URI schemaUri = rootModelDimensions.getSchemaUri();

        if (!isApplicableTo(schemaUri)) {
            throw new UnsupportedOperationException(getClass().getSimpleName()
                    + " can be used to read and write schemas only (" + schemaLoader.getSchemaSchemaUri() + ")");
        }

        final JsonSchemaLoader jsonSchemaLoader = schemaLoader.getJsonSchemaLoader();
        JsonSchema jsonSchema;
        Schema wrmlSchema = null;
        try {
            jsonSchema = jsonSchemaLoader.load(in, uri);
            wrmlSchema = schemaLoader.load(jsonSchema, schemaLoader.getDocumentSchemaUri());
            if (wrmlSchema == null) {
                throw new InvalidObjectException("Unable to deserialize InputStream to Model");
            }
        } catch (Exception e) {
            throw new ModelReadingException(
                    getClass().getSimpleName() + " encounter an error while attempting to read a JSON Schema ("
                            + uri + ").  Message: " + e.getMessage(),
                    null, this);
        }

        return (M) wrmlSchema;
    }

    @Override
    public void writeModel(final OutputStream out, final Model model, final ModelWriteOptions writeOptions)
            throws ModelWritingException, UnsupportedOperationException {

        final Context context = getContext();
        final SchemaLoader schemaLoader = context.getSchemaLoader();

        if (!(model instanceof Schema)) {
            throw new UnsupportedOperationException(getClass().getSimpleName()
                    + " can be used to read and write schemas only (" + schemaLoader.getSchemaSchemaUri() + ")");
        }

        final Schema wrmlSchema = (Schema) model;
        final ObjectWriter objectWriter = new ObjectMapper().writer(new DefaultPrettyPrinter());
        final JsonSchema jsonSchema = schemaLoader.getJsonSchemaLoader().load(wrmlSchema);

        try {
            objectWriter.writeValue(out, jsonSchema.getRootNode());
        } catch (final Exception e) {
            throw new ModelWritingException(
                    getClass().getSimpleName() + " encounter an error while attempting to write a JSON Schema ("
                            + model + ").  Message: " + e.getMessage(),
                    null, this);

        }

    }
}