YAML的Java實現——JYAML基本原理與示例（1）匯出資料為YAML格式檔案

1. Overview

JYAML是YAML的Java實現，YAML的全稱是YAML Ain't Markup Language，是否定遞迴定義，和LINUX的Linux Is Not UniX是一個意思。其結構之簡單，常常成為匯出或匯入配置檔案、資料結構等應用場景的常用API。

2. Download

http://jyaml.sourceforge.net/index.html

3. Basic Types

YAML包括Sequence和Map兩種基本資料格式。對於Sequence，其每一項會以“-”開頭。對於Map的每一項，key與value之間是用“:"來連線的。從屬關係則用空格來表示。這基本上就是YAML的全部語法了。

4. Sample Code

（1）Data

package com.sinosuperman.yaml;

public class Person {
	private String name;
	private int age;
	private Person spouse;
	private Person[] children;
	public Person(){
	}
	public void setName(String name) {
		this.name = name;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public void setSpouse(Person spouse) {
		this.spouse = spouse;
	}
	public void setChildren(Person[] children) {
		this.children = children;
	}
	public String getName() {
		return this.name;
	}
	public int getAge() {
		return this.age;
	}
	public Person getSpouse() {
		return this.spouse;
	}
	public Person[] getChildren() {
		return this.children;
	}
}

（2）Export Data（Dump Data to a YAML file）

package com.sinosuperman.yaml;

import java.io.File;
import java.io.FileNotFoundException;

import org.ho.yaml.Yaml;

public class TestYaml {
	
	public static void main(String[] args) {
		
		/* Initialize data. */
		Person michael = new Person();
		Person floveria = new Person();
		Person[] children = new Person[2];
		children[0] = new Person();
		children[1] = new Person();
		
		michael.setName("Michael Corleone");
		michael.setAge(24);
		floveria.setName("Floveria Edie");
		floveria.setAge(24);
		children[0].setName("boy");
		children[0].setAge(3);
		children[1].setName("girl");
		children[1].setAge(1);
		
		michael.setSpouse(floveria);
		floveria.setSpouse(michael);
		
		michael.setChildren(children);
		floveria.setChildren(children);
		
		/* Export data to a YAML file. */
		File dumpFile = new File("conf/testYaml.yaml");
		try {
			Yaml.dump(michael, dumpFile);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	}
}

（3）YAML file

--- &0 !com.sinosuperman.yaml.Person
age: 24
children: &2 !com.sinosuperman.yaml.Person[]
  - !com.sinosuperman.yaml.Person
    age: 3
    name: boy
  - !com.sinosuperman.yaml.Person
    age: 1
    name: girl
name: Michael Corleone
spouse: !com.sinosuperman.yaml.Person
  age: 24
  children: *2
  name: Floveria Edie
  spouse: *0

5. 快去試試吧~