Java设计模式--Java Builder模式

1、Java Builder模式主要是用一个内部类去实例化一个对象，避免一个类出现过多构造函数，而且构造函数如果出现默认参数的话，很容易出错。

public Person(String name)

Person(String name, int age)

Person(String name, int age, boolean sex)

2、Android OkHttp框架中Request、Response类都使用了Java Builder模式。

3、下面举一个小例子:

/**
 * @author SunKing1927 2015年11月2日
 *         Java Builder模式
 */
public class Person {
    private String name;
    private int age;
    private boolean sex;

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public boolean isSex() {
        return sex;
    }

    public static class Builder {
        private String name;
        private int age;
        private boolean sex;

        public Builder name(String n) {
            name = n;
            return this;
        }

        public Builder age(int a) {
            age = a;
            return this;
        }

        public Builder sex(boolean s) {
            sex = s;
            return this;
        }

        public Person build() {
            return new Person(this);
        }
    }

    private Person(Builder builder) {
        name = builder.name;
        age = builder.age;
        sex = builder.sex;
    }
}

public class MainRun {
    public static void main(String[] argv){
        Person person = new Person.Builder().name("StephenHe").age(20).sex(true).build();
        System.out.println(person.getName() + "\n" + person.getAge() + "\n" + person.isSex());
    }
}

4、参考博文：

http://www.cnblogs.com/moonz-wu/archive/2011/01/11/1932473.html