Json2Yaml.java

package dk.jarry.util;

import java.io.IOException;
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 com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;

public class Json2Yaml {

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

	public Json2Yaml() {
	}
	
	public Json2Yaml(Path sourcePath) {
		this.sourcePath = sourcePath;
	}

	public Json2Yaml(Path sourcePath, Path targetPath) {
		this.sourcePath = sourcePath;
		this.targetPath = targetPath;
	}

	public Json2Yaml(Path sourcePath, Path targetPath, Boolean replace) {
		this.sourcePath = sourcePath;
		this.targetPath = targetPath;
		this.replace = replace;
	}

	public String getYamlString() throws JsonParseException, JsonMappingException, IOException {

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

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

		String jsonString = new String(Files.readAllBytes(sourcePath));
		
		return getYamlString(jsonString);
	}

	public String getYamlString(String jsonString) throws IOException {

		JsonNode jsonNodeTree = new ObjectMapper().readTree(jsonString);

		String jsonAsYaml = new YAMLMapper().writeValueAsString(jsonNodeTree);

		return jsonAsYaml;

	}

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

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

		Files.write(targetPath, getYamlString().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>
*/