= Builder Pattern =
복잡한 인스턴스를 단계적으로 조립하기
  * 복잡한 구조를 한 번에 완성시키기 어려움. 그렇기 때문에 각 부분을 만들고 단계적으로 조립.

{{tag>Architecture Modeling Design_Pattern Creational}}

= Director =
<sxh java ; highlight : [9,10,11,12,13]>
/* Builder 역할의 인터페이스(API)를 사용해서 인스턴스 조립/생성. */
public class Director {
	private Builder builder;
	
	public Director(Builder builder) {
		this.builder = builder;
	}
	
	public void construct() {
		builder.setHeader();
		builder.setMessage("Hello", "World!", "안녕?", "세상아");
		builder.setFooter();
	}
}
</sxh>


= Builder, ConcreteBuilder =

<sxh java ; title: Builder>
/* 인스턴스의 각 부분을 만들기 위한 메소드 준비 */
public abstract class Builder {
	protected StringBuffer buffer = new StringBuffer();
	
	public abstract void setHeader();
	public abstract void setMessage(String... items);
	public abstract void setFooter();
}
</sxh>

<sxh java ; title: ConcreteBuilder>
public class PlainTextBuilder extends Builder {

	@Override
	public void setHeader() {
		buffer.append("====================\n");
	}

	@Override
	public void setMessage(String... items) {
		
		Stream.of(items).forEach(str -> {
			buffer.append(str);
			buffer.append("\n");
		});
		
	}

	public void print() {
		System.out.println(buffer);
		System.out.println("\n");
	}

	@Override
	public void setFooter() {
		buffer.append("====================");
	}
}
</sxh>

<sxh java ; title: ConcreteBuilder>
public class JavaCodeBuilder extends Builder {

	private String snippet1 = "public class JavaCodeBuilder {\r\n" + 
			"	public static void main(String[] args) {\r\n" + 
			"		System.out.println(";
	
	private String snippet2 = ");\r\n" + 
			"	}\r\n" + 
			"}";
	
	@Override
	public void setHeader() {
		buffer.append(snippet1);
	}

	@Override
	public void setMessage(String... items) {
		
		buffer.append("\"");
		Stream.of(items).forEach(str -> {
			buffer.append(str);
			buffer.append(" ");
		});
		buffer.append("\"");
	}
	
	@Override
	public void setFooter() {
		buffer.append(snippet2);
	}

	public void save() {
		String fileName = "JavaCodeBuilder.java";
		
		System.out.println(buffer);
		System.out.println();
		System.out.println(fileName + " 로 저장되었습니다.");
		
		try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(fileName))){
			bos.write(String.valueOf(buffer).getBytes());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}
</sxh>

= Client =
<sxh java>
public class Main {
	public static void main(String[] args) {
		PlainTextBuilder plainTextBuilder = new PlainTextBuilder();
		construct(plainTextBuilder);
		plainTextBuilder.print();
		
		JavaCodeBuilder javaCodeBuilder = new JavaCodeBuilder();
		construct(javaCodeBuilder);
		javaCodeBuilder.save();
	}
	
	private static void construct(Builder concreteBuilder) {
		Director plainTextDirector = new Director(concreteBuilder);
		plainTextDirector.construct();
	}
}


/*
====================
Hello
World!
안녕?
세상아
====================


public class JavaCodeBuilder {
	public static void main(String[] args) {
		System.out.println("Hello World! 안녕? 세상아 ");
	}
}

JavaCodeBuilder.java 로 저장되었습니다.
*/
</sxh>