Lombok中的@Builder注解的使用

作用

• @Builder注解的作用主要是用来生成对象，并且可以为对象链式赋值。

引入依赖

• 因为@Builder注解是lombok中的东西，所以第一步我们需要引入lombok的依赖，如下图：
• 

第二步给实体类加上@Builder注解

• 第二步我们需要给我们的实体类加上一个@Builder注解，如下图：
• 

第三步使用测试使用@Builder注解生成对象

• 

实体类加上@Builder注解之后的编译结果

• 实体类加上@Builder注解之后，编译之后会多出一个builder()方法，和一个CardBuilder静态内部类，如下图：

• 

• 

• 代码如下:

• public class Card {
      private int id;
      private String name;
      private boolean sex;
  
      public static Card.CardBuilder builder() {
          return new Card.CardBuilder();
      }
  
      public Card(int id, String name, boolean sex) {
          this.id = id;
          this.name = name;
          this.sex = sex;
      }
  
      public Card() {
      }
  
      public int getId() {
          return this.id;
      }
  
      public String getName() {
          return this.name;
      }
  
      public boolean isSex() {
          return this.sex;
      }
  
      public void setId(int id) {
          this.id = id;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public void setSex(boolean sex) {
          this.sex = sex;
      }
  
      public boolean equals(Object o) {
          if (o == this) {
              return true;
          } else if (!(o instanceof Card)) {
              return false;
          } else {
              Card other = (Card)o;
              if (!other.canEqual(this)) {
                  return false;
              } else if (this.getId() != other.getId()) {
                  return false;
              } else {
                  Object this$name = this.getName();
                  Object other$name = other.getName();
                  if (this$name == null) {
                      if (other$name == null) {
                          return this.isSex() == other.isSex();
                      }
                  } else if (this$name.equals(other$name)) {
                      return this.isSex() == other.isSex();
                  }
  
                  return false;
              }
          }
      }
  
      protected boolean canEqual(Object other) {
          return other instanceof Card;
      }
  
      public int hashCode() {
          int PRIME = true;
          int result = 1;
          int result = result * 59 + this.getId();
          Object $name = this.getName();
          result = result * 59 + ($name == null ? 43 : $name.hashCode());
          result = result * 59 + (this.isSex() ? 79 : 97);
          return result;
      }
  
      public String toString() {
          return "Card(id=" + this.getId() + ", name=" + this.getName() + ", sex=" + this.isSex() + ")";
      }
  
      public static class CardBuilder {
          private int id;
          private String name;
          private boolean sex;
  
          CardBuilder() {
          }
  
          public Card.CardBuilder id(int id) {
              this.id = id;
              return this;
          }
  
          public Card.CardBuilder name(String name) {
              this.name = name;
              return this;
          }
  
          public Card.CardBuilder sex(boolean sex) {
              this.sex = sex;
              return this;
          }
  
          public Card build() {
              return new Card(this.id, this.name, this.sex);
          }
  
          public String toString() {
              return "Card.CardBuilder(id=" + this.id + ", name=" + this.name + ", sex=" + this.sex + ")";
          }
      }
  }