juneau-core/juneau-marshall/src/main/java/org/apache/juneau/annotation/Builder.java

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package org.apache.juneau.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.*;

/**
 * Identifies a class as a builder for a POJO class.
 *
 * <h5 class='figure'>Example:</h5>
 * <p class='bcode w800'>
 * 	<jc>// POJO class.</jc>
 * 	<ja>@Builder</ja>(MyBeanBuilder.<jk>class</jk>)
 * 	<jk>public class</jk> MyBean {
 *
 * 		<jc>// Read-only properties.</jc>
 * 		<jk>public final</jk> String <jf>foo</jf>;
 * 		<jk>public final int</jk> <jf>bar</jf>;
 *
 * 		<jc>// Constructor that takes in a builder.</jc>
 * 		<jk>public</jk> MyBean(MyBeanBuilder b) {
 * 			<jk>this</jk>.<jf>foo</jf> = b.foo;
 * 			<jk>this</jk>.<jf>bar</jf> = b.bar;
 * 		}
 * 	}
 *
 * 	<jc>// Builder class.</jc>
 * 	<jk>public class</jk> MyBeanBuilder {
 * 		<jk>public</jk> String <jf>foo</jf>;
 * 		<jk>public int</jk> <jf>bar</jf>;
 *
 * 		<jc>// Method that creates the bean.</jc>
 * 		<jk>public</jk> MyBean build() {
 * 			<jk>return new</jk> MyBean(<jk>this</jk>);
 * 		}
 *
 * 		<jc>// Bean property setters.</jc>
 * 	}
 * </p>
 *
 * <ul class='seealso'>
 * 	<li class='link'>{@doc juneau-marshall.Transforms.PojoBuilders}
 * </ul>
 */
@Documented
@Target({TYPE})
@Retention(RUNTIME)
@Inherited
public @interface Builder {

	/**
	 * The builder for this class.
	 */
	Class<?> value() default Null.class;
}