构建者模式

/**
 * builder(构建者模式)
 *
 */
public class User {

	private String id ;
	private String name ;
	private Integer age ;
	
	public static Builder builder(){
		return new Builder();
	}
	
	public static class Builder{
		private String id ;
		private String name ;
		private Integer age ;
 
		public Builder id(String id) {
			this.id = id ;
			return this;
		}
 
		public Builder name(String name) {
			this.name = name ;
			return this ;
		}
		
		public Builder age(Integer age) {
			this.age = age ; 
			return this;
		}
 
		public User build() {
			return new User(this);
		}
		
		public User build2() {
			return new User(this.id , this.name , this.age);
		}
		
	}
	
	public String getId() {
		return id;
	}
 
	public void setId(String id) {
		this.id = id;
	}
 
	public String getName() {
		return name;
	}
 
	public void setName(String name) {
		this.name = name;
	}
 
	public Integer getAge() {
		return age;
	}
 
	public void setAge(Integer age) {
		this.age = age;
	}
 
	public User() {
		super();
	}
 
	public User(String id, String name, Integer age) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
	}
	
	public User(Builder builder) {
		this.id = builder.id;
		this.name = builder.name ;
		this.age = builder.age;
	}
	
	public static void main(String[] args) {
		User user = User.builder()
        		.id("11")
        		.name("小明")
        		.age(17)
        		.build();
	}