YamlToJson.java

/**
 * Copyright (C) 2015 Zalando SE (http://tech.zalando.com)
 *
 * 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.zalando.stups.swagger.codegen;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URL;
import java.nio.file.Files;

import org.apache.commons.io.IOUtils;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.io.Resources;

import io.swagger.util.Yaml;

/**
 * @author  jbellmann
 */
public class YamlToJson {

    private String outputDirectoryPath;

    private String yamlInputPath;

    private CodegeneratorLogger logger = new SystemOutCodegeneratorLogger();

    private YamlToJson(final String yamlInputPath, final String outputDirectoryPath,
            final CodegeneratorLogger codegeneratorLogger) {
        this.yamlInputPath = yamlInputPath;
        this.outputDirectoryPath = outputDirectoryPath;
        this.logger = codegeneratorLogger;
    }

    public void convert() {
        logger.info("Generate .json file from .yaml");

        File outputDirectory = new File(outputDirectoryPath);
        if (!outputDirectory.exists()) {
            outputDirectory.mkdirs();
            logger.info("OutputDirectory created");
        }

        File jsonFile = new File(outputDirectory, getYamlFilename() + ".json");
        FileWriter fileWriter = null;
        try {

            fileWriter = new FileWriter(jsonFile);
            fileWriter.write(getYamlFileContentAsJson());
            fileWriter.flush();
            logger.info("File written to " + jsonFile.getAbsolutePath());
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        } finally {
            IOUtils.closeQuietly(fileWriter);
        }
    }

    protected String getYamlFileContentAsJson() throws IOException {
        String data = "";
        if (yamlInputPath.startsWith("http") || yamlInputPath.startsWith("https")) {

            data = new String(Resources.toByteArray(new URL(yamlInputPath)));
        } else {
            data = new String(Files.readAllBytes(java.nio.file.Paths.get(new File(yamlInputPath).toURI())));
        }

        ObjectMapper yamlMapper = Yaml.mapper();
        JsonNode rootNode = yamlMapper.readTree(data);

        // must have swagger node set
        JsonNode swaggerNode = rootNode.get("swagger");

        return rootNode.toString();
    }

    protected String getYamlFilename() {
        if (yamlInputPath.startsWith("http") || yamlInputPath.startsWith("https")) {
            int lastSlashIndex = yamlInputPath.lastIndexOf("/");
            String filename = yamlInputPath.substring(lastSlashIndex + 1);
            return filenameSubstring(filename);
        } else {
            File file = new File(yamlInputPath);
            if (!file.exists()) {
                throw new RuntimeException("Api-File not found: " + yamlInputPath);
            } else {
                String filename = file.getName();
                return filenameSubstring(filename);
            }
        }
    }

    protected String filenameSubstring(String filename) {
        return filename.substring(0, filename.indexOf("."));
    }

    public static YamlToJsonBuilder builder() {
        return new YamlToJsonBuilder();
    }

    public static class YamlToJsonBuilder {
        private String yamlInputPath;
        private String outputDirectoryPath;
        private CodegeneratorLogger codegeneratorLogger = new SystemOutCodegeneratorLogger();

        public YamlToJsonBuilder withYamlInputPath(final String yamlInputPath) {
            this.yamlInputPath = yamlInputPath;
            return this;
        }

        public YamlToJsonBuilder withOutputDirectoryPath(final String outputDirectoryPath) {
            this.outputDirectoryPath = outputDirectoryPath;
            return this;
        }

        public YamlToJsonBuilder withCodegeneratorLogger(final CodegeneratorLogger codegeneratorLogger) {
            this.codegeneratorLogger = codegeneratorLogger;
            return this;
        }

        public YamlToJson build() {
            return new YamlToJson(yamlInputPath, outputDirectoryPath, codegeneratorLogger);
        }
    }
}