建造者

• 建造者设计模式是什么？有啥么用？

  • 链式调用

• 建造者的常用写法

• 建造者的神器？

  • lombok

User.java

package course.patterns.builder;

public class User {

    private String name;
    private Integer age;
    private String info;
    private String password;
    private String balance;

    private User(Builder builder) {
        this.name = builder.name;
        this.age = builder.age;
        this.info = builder.info;
        this.password = builder.password;
        this.balance = builder.balance;
    }

    public static class Builder {
        private String name;
        private Integer age;
        private String info;
        private String password;
        private String balance;

        public static Builder of() {
            return new Builder();
        }

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

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

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

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

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

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

    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 String getInfo() {
        return info;
    }

    public void setInfo(String info) {
        this.info = info;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getBalance() {
        return balance;
    }

    public void setBalance(String balance) {
        this.balance = balance;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", info='" + info + '\'' +
                ", password='" + password + '\'' +
                ", balance='" + balance + '\'' +
                '}';
    }
}

 

UserApp1

package course.patterns.builder;

public class UserApp1 {
    // public static void main(String[] args) {
    //     User user = new User();
    //     user.setName("xxx");
    //     user.setAge(23);
    //     user.setPassword("122333");
    //
    //     fooUser(user);
    // }
    //


    public static void main(String[] args) {
        User user = User.Builder.of()
                .name("")
                .age(23)
                .balance("123")
                .info("")
                .build();

        fooUser(user);

        fooUser(User.Builder.of()
                .name("")
                .age(23)
                .balance("123")
                .info("")
                .build());
    }

    private static void fooUser(User user) {
    }
}

 

User2.java

package course.patterns.builder;

import lombok.Builder;
import lombok.Data;

@Builder
@Data
public class User2 {
    private String name;
    private Integer age;
    private String info;
    private String password;
    private String balance;
}

 

 

UserApp2.java

package course.patterns.builder;

public class User2App {
    public static void main(String[] args) {
        User2 fly = User2.builder().name("Fly")
                .age(23)
                .balance("123")
                .info("")
                .build();

    }
}