java Lombok 我们可以在一个类上同时使用 @Builder 和 @Value 吗

Lombok Can we use @Builder and @Value together on a single class

提问by Anil

First of all thanks to Lombok, our java code is now much sleeker and cleaner. My use case is I want to create an immutable class. For that I would use @Value annotation. Also I want to use builder capabilities, for that I would use @Builder annotation. My question is if we can use both @Builder and @Value together on a single class. Is it a good practice recommended by Lombok users/developers.

首先感谢 Lombok，我们的 Java 代码现在更加流畅和干净。我的用例是我想创建一个不可变的类。为此，我将使用 @Value 注释。此外，我想使用构建器功能，为此我将使用 @Builder 注释。我的问题是我们是否可以在一个类中同时使用 @Builder 和 @Value 。这是 Lombok 用户/开发人员推荐的好习惯吗？

采纳答案by Justin

Of course you can. To check, simply delombokyour code and see what it generates. Take this example:

当然可以。要检查，只需对您的代码进行delombok并查看它生成的内容。拿这个例子：

@Builder
@Value
public class Pair {
    private Object left;
    private Object right;
}

After delombokification, this produces:

在 delombokification 之后，这会产生：

public class Pair {
    private Object left;
    private Object right;

    @java.beans.ConstructorProperties({ "left", "right" })
    Pair(Object left, Object right) {
        this.left = left;
        this.right = right;
    }

    public static PairBuilder builder() {
        return new PairBuilder();
    }

    public Object getLeft() {
        return this.left;
    }

    public Object getRight() {
        return this.right;
    }

    public boolean equals(Object o) {
        if (o == this) return true;
        if (!(o instanceof Pair)) return false;
        final Pair other = (Pair) o;
        final Object this$left = this.left;
        final Object other$left = other.left;
        if (this$left == null ? other$left != null : !this$left.equals(other$left)) return false;
        final Object this$right = this.right;
        final Object other$right = other.right;
        if (this$right == null ? other$right != null : !this$right.equals(other$right)) return false;
        return true;
    }

    public int hashCode() {
        final int PRIME = 59;
        int result = 1;
        final Object $left = this.left;
        result = result * PRIME + ($left == null ? 0 : $left.hashCode());
        final Object $right = this.right;
        result = result * PRIME + ($right == null ? 0 : $right.hashCode());
        return result;
    }

    public String toString() {
        return "Pair(left=" + this.left + ", right=" + this.right + ")";
    }

    public static class PairBuilder {
        private Object left;
        private Object right;

        PairBuilder() {
        }

        public Pair.PairBuilder left(Object left) {
            this.left = left;
            return this;
        }

        public Pair.PairBuilder right(Object right) {
            this.right = right;
            return this;
        }

        public Pair build() {
            return new Pair(left, right);
        }

        public String toString() {
            return "Pair.PairBuilder(left=" + this.left + ", right=" + this.right + ")";
        }
    }
}

So you can clearly use both @Valueand @Builder

所以你可以清楚地同时使用@Value和@Builder

回答by Tom Andersen

As of version 1.16.10, the constructor is notpublic when you use both.

从版本 1.16.10 开始，当您同时使用两者时，构造函数不是公共的。

You can add @AllArgsConstructor to compensate for this.

您可以添加 @AllArgsConstructor 来弥补这一点。

回答by vikas

Short Answer: Yes, you can always use @Value and @Builder together. I have used this in my production code and it works fine.

简短回答：是的，您始终可以同时使用 @Value 和 @Builder。我在我的生产代码中使用了它，它工作正常。

Long Answer: You can use them together. The one thing you want to keep in mind is that the AllArgsConstructor provided by @Value will be private to package since lombok v1.16.0. So, if you want that to be public you will have to access control that additionally by @AllArgsConstructor. In my case though, private constructor is what I really wanted. My aim of using @Builder was to really allow the the object instantiation only using the builder and not use constructor or setter methods later.

长答案：您可以一起使用它们。您要记住的一件事是，从 lombok v1.16.0 开始，@Value 提供的 AllArgsConstructor 将是私有的包。因此，如果您希望将其公开，则必须另外通过@AllArgsConstructor 访问控制。不过就我而言，私有构造函数才是我真正想要的。我使用@Builder 的目的是真正允许仅使用构建器进行对象实例化，而不再使用构造函数或 setter 方法。

Here is my code:

这是我的代码：

@Value
@Builder
@ApiModel(description = "Model to represent annotation")
public class Annotation {

    @NonNull
    @ApiModelProperty(value = "Unique identifier")
    private String id;

}

@Value type from eclipse

来自 eclipse 的 @Value 类型

@Builder tyoe from eclipse

@Builder tyoe 来自 eclipse