与杰克逊的反序列化的建造者样式

Question

要求 :

1. 想用Builder模式
2. 杰克逊进行反序列化
3. 不想使用setter

我确信杰克逊的工作基于POJO上的吸气剂和制定者.既然,我有建造者模式,再没有重要的东西.在这种情况下,我们如何在Builder模式的帮助下指示jackson反序列化？

任何帮助,将不胜感激.我试过@JsonDeserialize(builder = MyBuilder.class)并且无法正常工作.

这在REST球衣中是必需的.我目前是杰克逊编组和解编的jersey-media-jackson maven模块.

Answer 1

@JsonDeserialize如果你有jackson-databind类路径,那就是要走的路.以下片段是从Jackson文档中复制的:

@JsonDeserialize(builder=ValueBuilder.class)
public class Value {
  private final int x, y;
  protected Value(int x, int y) {
    this.x = x;
    this.y = y;
  }
}

public class ValueBuilder {
  private int x, y;

  // can use @JsonCreator to use non-default ctor, inject values etc
  public ValueBuilder() { }

  // if name is "withXxx", works as is: otherwise use @JsonProperty("x") or @JsonSetter("x")!
  public ValueBuilder withX(int x) {
    this.x = x;
    return this; // or, construct new instance, return that
  }
  public ValueBuilder withY(int y) {
    this.y = y;
    return this;
  }

  public Value build() {
    return new Value(x, y);
  }
}

或者,@JsonPOJOBuilder如果您不喜欢具有with前缀的方法名称,请使用:

@JsonPOJOBuilder(buildMethodName="create", withPrefix="con")
public class ValueBuilder {
  private int x, y;

  public ValueBuilder conX(int x) {
    this.x = x;
    return this; // or, construct new instance, return that
  }
  public ValueBuilder conY(int y) {
    this.y = y;
    return this;
  }

  public Value create() { return new Value(x, y); }
}