SchemaMapper.java

/**
 * Copyright © 2010-2014 Nokia
 *
 * 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.jsonschema2pojo;

import java.io.IOException;
import java.net.URI;
import java.net.URL;

import org.jsonschema2pojo.rules.RuleFactory;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.sun.codemodel.JCodeModel;
import com.sun.codemodel.JPackage;
import com.sun.codemodel.JType;

/**
 * Generates Java types from a JSON schema. Can accept a factory which will be
 * used to create type generation rules for this mapper.
 */
public class SchemaMapper {
    private static final JsonNodeFactory NODE_FACTORY = JsonNodeFactory.instance;

    private final RuleFactory ruleFactory;
    private final SchemaGenerator schemaGenerator;

    /**
     * Create a schema mapper with the given {@link RuleFactory}.
     *
     * @param ruleFactory
     *            A factory used by this mapper to create Java type generation
     *            rules.
     * @param schemaGenerator
     *            the generator that this mapper will use if the config dictates
     *            that the input documents are plain json (not json schema)
     */
    public SchemaMapper(RuleFactory ruleFactory, SchemaGenerator schemaGenerator) {
        this.ruleFactory = ruleFactory;
        this.schemaGenerator = schemaGenerator;
    }

    /**
     * Create a schema mapper with the default {@link RuleFactory}
     * implementation.
     *
     * @see RuleFactory
     */
    public SchemaMapper() {
        this(new RuleFactory(), new SchemaGenerator());
    }

    /**
     * Reads a schema and adds generated types to the given code model.
     *
     * @param codeModel
     *            the java code-generation context that should be used to
     *            generated new types
     * @param className
     *            the name of the parent class the represented by this schema
     * @param packageName
     *            the target package that should be used for generated types
     * @param schemaUrl
     *            location of the schema to be used as input
     * @return The top-most type generated from the given file
     * @throws IOException
     *             if the schema content cannot be read
     */
    public JType generate(JCodeModel codeModel, String className, String packageName, URL schemaUrl) throws IOException {

        JPackage jpackage = codeModel._package(packageName);

        ObjectNode schemaNode = readSchema(schemaUrl);

        return ruleFactory.getSchemaRule().apply(className, schemaNode, jpackage, new Schema(null, schemaNode, schemaNode));

    }

    private ObjectNode readSchema(URL schemaUrl) {

        switch (ruleFactory.getGenerationConfig().getSourceType()) {
            case JSONSCHEMA:
                ObjectNode schemaNode = NODE_FACTORY.objectNode();
                schemaNode.put("$ref", schemaUrl.toString());
                return schemaNode;
            case JSON:
                return schemaGenerator.schemaFromExample(schemaUrl);
            default:
                throw new IllegalArgumentException("Unrecognised source type: " + ruleFactory.getGenerationConfig().getSourceType());
        }

    }

    public JType generate(JCodeModel codeModel, String className, String packageName, String json,
            URI schemaLocation) throws IOException {

        JPackage jpackage = codeModel._package(packageName);

        JsonNode schemaNode = objectMapper().readTree(json);

        return ruleFactory.getSchemaRule().apply(className, schemaNode, jpackage,
                new Schema(schemaLocation, schemaNode, schemaNode));
    }

    public JType generate(JCodeModel codeModel, String className, String packageName, String json) throws IOException {

        JPackage jpackage = codeModel._package(packageName);

        JsonNode schemaNode = null;
        if (ruleFactory.getGenerationConfig().getSourceType() == SourceType.JSON) {
            JsonNode jsonNode = objectMapper().readTree(json);
            schemaNode = schemaGenerator.schemaFromExample(jsonNode);
        } else {
            schemaNode = objectMapper().readTree(json);
        }

        return ruleFactory.getSchemaRule().apply(className, schemaNode, jpackage, new Schema(null, schemaNode, schemaNode));
    }

    private ObjectMapper objectMapper() {
        return new ObjectMapper()
                .enable(JsonParser.Feature.ALLOW_COMMENTS)
                .enable(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS);
    }

}