下面是示例JSON字符串。我想解析这个嵌套的JSON对象，即使嵌套对象有相同的名称。有时我们可能会有多个层次的嵌套对象。我厌倦了Jackson嵌套对象解析，但这对我不起作用。解析完对象后，我想把它转换成不同的格式。请帮助我解析这个JSON。先谢了。

{
      "operator": "and",
      "predicates": [
        {
          "operator": "and",
          "predicates": [
            {
              "columnName": "userName",
              "datatype": "string",
              "input": "text",
              "operand": "equal",
              "value": "xxxx"
            },
            {
              "columnName": "Age",
              "datatype": "number",
              "input": "number",
              "operand": "greater_or_equal",
              "value": "21"
            }
          ]
        },
        {
          "operator": "and",
          "predicates": [
            {
              "columnName": "userName",
              "datatype": "string",
              "input": "text",
              "operand": "not_equal",
              "value": "nnn"
            },
            {
              "columnName": "Birthday",
              "datatype": "date",
              "input": "date_picker",
              "operand": "in",
              "value": "2020-07-23,2020-07-24"
            }
          ]
        }
      ]
    }

下面是java中的代码

import java.util.Map;
import com.fasterxml.jackson.annotation.JsonProperty;

public class Predicates {
    
    private String columnName;
    private String datatype;
    private String input;
    private String operator;
    private String value;
    private String operand;
    
    /**
     * 
     */
    
    private List<Predicates> predicates;
    
    @JsonProperty("predicates")
    private void unpackNested(Map<String,Object> predicates) {
        this.columnName = (String)predicates.get("columnName");
        this.datatype = (String)predicates.get("datatype");
        this.input = (String)predicates.get("input");
        this.operator = (String)predicates.get("operator");
        this.value = (String)predicates.get("value");
        this.operand = (String)predicates.get("operand");
    }
    
    
    public String getColumnName() {
        return columnName;
    }
    public void setColumnName(String columnName) {
        this.columnName = columnName;
    }
    public String getDatatype() {
        return datatype;
    }
    public void setDatatype(String datatype) {
        this.datatype = datatype;
    }
    public String getInput() {
        return input;
    }
    public void setInput(String input) {
        this.input = input;
    }
    public String getOperator() {
        return operator;
    }
    public void setOperator(String operator) {
        this.operator = operator;
    }
    public String getValue() {
        return value;
    }
    public void setValue(String value) {
        this.value = value;
    }

    public String getOperand() {
        return operand;
    }

    public void setOperand(String operand) {
        this.operand = operand;
    }
    public List<Predicates> getPredicates() {
        return predicates;
    }
    public void setPredicates(List<Predicates> predicates) {
        this.predicates = predicates;
    }
}

解析

ObjectMapper mapper = new ObjectMapper();
Predicates pr = mapper.readValue(json, Predicates.class);