Yaml2Json.java

package dk.jarry.util;

import java.io.IOException;
import java.io.StringReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.UUID;

import javax.json.Json;
import javax.json.JsonObject;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;

public class Yaml2Json {

	private Path sourcePath;
	private Path targetPath;
	private Boolean replace = Boolean.FALSE;

	public Yaml2Json() {	
	}
	
	public Yaml2Json(Path path) {
		this.sourcePath = path;
	}

	public Yaml2Json(Path sourcePath, Path targetPath) {
		this.sourcePath = sourcePath;
		this.targetPath = targetPath;
	}

	public Yaml2Json(Path sourcePath, Path targetPath, Boolean replace) {
		this.sourcePath = sourcePath;
		this.targetPath = targetPath;
		this.replace = replace;
	}

	public JsonObject getJson() throws JsonParseException, JsonMappingException, IOException {

		JsonObject jsonObject = null;

		if (sourcePath == null) {
			throw new IllegalArgumentException("sourcePath is null");
		}

		if (!Files.exists(sourcePath)) {
			throw new IOException(sourcePath.toString() + " is not on disk");
		}

		ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
		Object object = mapper.readValue(sourcePath.toFile(), Object.class);

		ObjectMapper jsonWriter = new ObjectMapper();
		String jsonString = jsonWriter.writeValueAsString(object);

		jsonObject = Json.createReader(new StringReader(jsonString)).readObject();

		return jsonObject;
	}

	public JsonObject getJson(String yamlString) throws JsonParseException, JsonMappingException, IOException {

		JsonObject jsonObject = null;

		ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
		Object object = mapper.readValue(yamlString, Object.class);

		ObjectMapper jsonWriter = new ObjectMapper();
		String jsonString = jsonWriter.writeValueAsString(object);

		jsonObject = Json.createReader(new StringReader(jsonString)).readObject();

		return jsonObject;
	}

	public String getJsonString() throws JsonParseException, JsonMappingException, IOException, ScriptException {

		ScriptEngineManager manager = new ScriptEngineManager();
		ScriptEngine scriptEngine = manager.getEngineByName("nashorn");
		scriptEngine.put("jsonString", getJson().toString());
		scriptEngine.eval("result = JSON.stringify(JSON.parse(jsonString), null, 3)");
		String prettyPrintedJson = (String) scriptEngine.get("result");

		return prettyPrintedJson;
	}

	public void save() throws JsonParseException, JsonMappingException, IOException, ScriptException {

		if (targetPath == null) {
			targetPath = Paths.get(sourcePath.toString().replace(".yaml", ".json"));
		}
		if (Files.exists(targetPath)) {
			if (replace) {
				Files.delete(targetPath);
			} else {
				targetPath = Paths.get(targetPath.toString(), "_" + UUID.randomUUID().toString());
			}
		}

		if (Files.exists(targetPath)) {
			targetPath = Paths.get(targetPath.toString(), "_" + UUID.randomUUID().toString());
		}

		Files.write(targetPath, getJsonString().getBytes(), StandardOpenOption.CREATE);

	}

}

/**
* Add to pom.xml
*
*<dependency>
*	<groupId>com.fasterxml.jackson.dataformat</groupId>
*	<artifactId>jackson-dataformat-yaml</artifactId>
*	<version>2.9.5</version>
*</dependency>
*<dependency>
*	<groupId>com.fasterxml.jackson.core</groupId>
*	<artifactId>jackson-databind</artifactId>
*	<version>2.9.5</version>
*</dependency>
*/