分为指导者，抽象建造者，具体建造者
有一个例子

import java.util.*;
import junit.framework.*;

//不同的媒体形式:

class media extends arraylist {}
class book extends media {}
class magazine extends media {}
class website extends media {}

// 不同媒体的组成元素:

class mediaitem {
　private string s;
　public mediaitem(string s) { this.s = s; }
　public string tostring() { return s; }
}

class chapter extends mediaitem {
　public chapter(string s) { super(s); }
}

class article extends mediaitem {
　public article(string s) { super(s); }
}

class webitem extends mediaitem {
　public webitem(string s) { super(s); }
}

// 抽象建造者角色，它规范了所有媒体建造的步骤:

class mediabuilder {
　public void buildbase() {}
　public void addmediaitem(mediaitem item) {}
　public media getfinishedmedia() { return null; }
}

//具体建造者角色

class bookbuilder extends mediabuilder {
　private book b;
　public void buildbase() {
　　system.out.println("building book framework");
　　b = new book();
　}

　public void addmediaitem(mediaitem chapter) {
　　system.out.println("adding chapter " + chapter);
　　b.add(chapter);
　}
　public media getfinishedmedia() { return b; }
}

class magazinebuilder extends mediabuilder {
　private magazine m;
　public void buildbase() {
　　system.out.println("building magazine framework");
　　m = new magazine();
　}

　public void addmediaitem(mediaitem article) {
　　system.out.println("adding article " + article);
　　m.add(article);
　}
　public media getfinishedmedia() { return m; }
}

class websitebuilder extends mediabuilder {
　private website w;
　public void buildbase() {
　　system.out.println("building web site framework");
　　w = new website();
　}

　public void addmediaitem(mediaitem webitem) {
　　system.out.println("adding web item " + webitem);
　　w.add(webitem);
　}

　public media getfinishedmedia() { return w; }
}

//指导者角色，也叫上下文
class mediadirector {
　private mediabuilder mb;
　public mediadirector(mediabuilder mb) {
　　this.mb = mb; //具有策略模式相似特征的
　}

　public media producemedia(list input) {
　　mb.buildbase();
　　for(iterator it = input.iterator(); it.hasnext();)
　　　mb.addmediaitem((mediaitem)it.next());
　　　return mb.getfinishedmedia();
　}
};

//测试程序――客户程序角色

public class buildmedia extends testcase {
　private list input = arrays.aslist(new mediaitem[] {
　　new mediaitem("item1"), new mediaitem("item2"),
　　new mediaitem("item3"), new mediaitem("item4"),
　});

　public void testbook() {
　　mediadirector buildbook = new mediadirector(new bookbuilder());
　　media book = buildbook.producemedia(input);
　　string result = "book: " + book;
　　system.out.println(result);
　　assertequals(result, "book: [item1, item2, item3, item4]");
　}

　public void testmagazine() {
　　mediadirector buildmagazine = new mediadirector(new

magazinebuilder());
　　media magazine = buildmagazine.producemedia(input);
　　string result = "magazine: " + magazine;
　　system.out.println(result);
　　assertequals(result, "magazine: [item1, item2, item3, item4]");
　}

　public void testwebsite(){
　　mediadirector buildwebsite = new mediadirector(new

websitebuilder());
　　media website = buildwebsite.producemedia(input);
　　string result = "web site: " + website;
　　system.out.println(result);
　　assertequals(result, "web site: [item1, item2, item3, item4]");
　}

　public static void main(string[] args) {
　　junit.textui.testrunner.run(buildmedia.class);
　}

}