builder模式

开发中如果遇到对象有多种属性时，构造方法即可能携带大量参数，这些参数会降低代码的可读性，不查看源码可能无法分辨各个参数的实际意义。这时候使用build模式，可以迅速增加代码可读性。
创建一个静态的build内部类，并让它拥有和外部类相同的属性：
例：

public class CommonInfo {

    public CommonInfo(Builder builder){
        this.age = builder.age;
        this.height = builder.height;
        this.sex = builder.sex;
    }
    private String age;
    private String height;
    private String sex;

    public String getAge() {
        return age;
    }

    public String getHeight() {
        return height;
    }

    public String getSex() {
        return sex;
    }

    static class Builder{

        private String age;
        private String height;
        private String sex;

        public Builder setAge(String age) {
            this.age = age;
            return this;
        }

        public Builder setHeight(String height) {
            this.height = height;
            return this;
        }

        public Builder setSex(String sex) {
            this.sex = sex;
            return this;
        }

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

public class Test {

    public static void main(String s[]){
        CommonInfo.Builder builder = new CommonInfo.Builder();
        CommonInfo info =builder.setAge("12").setHeight("50KG").setSex("man").build();
        System.out.println(info.getAge()+info.getHeight()+info.getSex());
    }
}