构建者模式（Builder）示例代码

 package com.test;

 /**
  * Created by xiaonanhai on 2015/5/30.
  */
 public class Builder {

     private String name;
     private int age;
     private String gender;

     private Builder(BuilderFactoryImpl builderFactoryImpl){

         this.name = builderFactoryImpl.name;
         this.age = builderFactoryImpl.age;
         this.gender = builderFactoryImpl.gender;
     }

     public String getName() {
         return name;
     }

     public int getAge() {
         return age;
     }

     public String getGender() {
         return gender;
     }

     public static class BuilderFactoryImpl implements BuilderFactory{

         private String name;
         private int age;
         private String gender;

         public BuilderFactoryImpl setName(String name) {
             this.name = name;
             return this;
         }

         public BuilderFactoryImpl setAge(int age) {
             this.age = age;
             return this;
         }

         public BuilderFactoryImpl setGender(String gender) {
             this.gender = gender;
             return this;
         }

         @Override
         public Builder build() {
             return new Builder(this);
         }
     }

     public interface BuilderFactory{

         Builder build();
     }

     @Override
     public String toString() {
         return "Builder{" +
                 "name='" + name + '\'' +
                 ", age=" + age +
                 ", gender='" + gender + '\'' +
                 '}';
     }

     public static void main(String[] args) {

         Builder builder = new Builder.BuilderFactoryImpl()
                 .setName("小男孩")
                 .setGender("男")
                 .setAge(29)
                 .build();
         System.out.println(builder.toString());
     }
 }