java - @RequestBody 映射复杂的 json 对象

Question

我需要将下面的 json 转换为 @RequestBody 的 java 对象。

{
    "entity": {
        "id": 3,
        "name": "james"
    },
    "conjunction": "OR",
    "conditions": [
        {
            "operation": "equalTo",
            "dataKey": "department",
            "dataType": "string",
            "value": "abc"
        },
        {
            "operation": "notEqualTo",
            "dataKey": "ID",
            "dataType": "number",
            "value": "100"
        },
        {
            "operation": "notEqualTo",
            "dataKey": "name",
            "dataType": "strubg",
            "value": "jack"
        },
        {
            "operation": "between",
            "dataKey": "END_DATE",
            "dataType": "date",
            "value1": "20180502",
            "value2": "20180519"
        }
    ]
}

数组中的前三个元素对应于下面的 java 对象。

public class ComparisonCondition extends Condition {
    private String value;
}

最后一个元素对应于对象下方。

public class BetweenCondition extends Condition {
    private String value1;
    private String value2;
}

它们都继承自下面的对象。

public class Condition {
    private String dataKey;
    private String dataType;
    private String operation;
}

spring mvc 方法如下。

@RequestMapping(value = RequestAction.FILTER, method = RequestMethod.POST)
public List<Student>  filter(
        @RequestBody  Filter<Student> filterConfig) {   
    return null;

}

过滤器对象如下。

public class Filter<T> {
    private String conjunction;
    private T entity;
    private List<Condition> conditions;
}

如何成功将json映射到java对象？
目前它报告 "Could not read JSON: Unrecognized field "value" (class com.ssc.rest.entity.Condition), not marked as ignorable (3 known properties: "dataType", "dataKey", "operation"])

Answer 1

对于您的错误，如果 jackson 解析器不知道某个字段，则会引发异常。

您可以通过添加注释来避免它:

@JsonIgnore(ignoreUnknown=true)

在目标对象上。

对于您的映射，我建议您根据您的 json 输入创建一个对象，然后手动映射到您的目标对象。