将 JSON 映射到 POJO 时发生 UnrecognizedPropertyException

UnrecognizedPropertyException when mapping JSON to POJO

我正在使用 Jackson API 在一组 POJO 类 的帮助下将 JSON 文件解析为 objects。但是当 ObjectMapper 到达 @title 字段时,出现以下 UnrecognizedPropertyException 错误:

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "@title" (class gmit.Exit), not marked as ignorable (2 known properties: "title", "direction"])
 at [Source: C:\Users\Brian\Documents\Eclipse\Projects\AI_Project_Grail_Quest_3\bin\resources\game.json; line: 13, column: 24] (through reference chain: gmit.Location["location"]->Object[][0]->gmit.Location["exit"]->Object[][0]->gmit.Exit["@title"])

这是正在解析的 JSON 文件:

http://hastebin.com/qamacarumu.pl

我知道这是因为 属性 没有被识别为错误状态,但我不确定为什么,因为我在 Exit POJO 中声明了这个字段。有人建议将 @JsonProperty 添加到这样的字段中,但似乎没有用:

@JsonProperty("title")
private String[] title;

有人知道如何解决这个错误吗?或者您能否解释为什么尽管 Exit POJO 中存在标题字段仍会抛出此错误?

这些是 POJO 的:

地点:

import java.util.Arrays;

public class Location {

    private Location[] location;

    private String description;

    private String name;

    private Exit[] exit;



    public Location[] getLocation() {
        return location;
    }

    public void setLocation(Location[] location) {
        this.location = location;
    }

    public String getDescription ()
    {
        return description;
    }

    public void setDescription (String description)
    {
        this.description = description;
    }

    public String getName ()
    {
        return name;
    }

    public void setName (String name)
    {
        this.name = name;
    }

    public Exit[] getExit() {
        return exit;
    }

    public void setExit(Exit[] exit) {
        this.exit = exit;
    }

    @Override
    public String toString() {
        return "Location [location=" + Arrays.toString(location)
                + ", description=" + description + ", name=" + name + ", exit="
                + Arrays.toString(exit) + "]";
    }



}

退出:

public class Exit {

    @JsonProperty("title")
    private String[] title;

    private String[] direction;


    public String[] getTitle() {
        return title;
    }
    public void setTitle(String[] title) {
        this.title = title;
    }
    public String[] getDirection() {
        return direction;
    }
    public void setDirection(String[] direction) {
        this.direction = direction;
    }

}

您的注释不应该是 @JsonProperty("@title"),因为那是 JSON 中的键的名称? 另请注意,根据您的版本,Jackson 带有两个不同的名称空间。这很容易成为陷阱

  • org.codehaus.jackson
  • com.fasterxml.jackson

所以请确保使用正确的注释