java - Spring/Hibernate 响应中的属性为空

Question

我有一个 Javascript 应用程序，它使用 Java 作为后端，并带有 Hibernate、Spring 和 MySQL DB。当读取数据时，一切正常且符合预期，但当尝试在客户端编辑它时，我可以看到奇怪的行为。即使我的服务器请求看起来像这样:

{"data":{"可拖动":true,"可调整大小":true,"StartDate":"2012-09-13T18:00:00+02:00","EndDate":"2012 -09-14T04:00:00+02:00","Cls":"","名称":" secret 任务","Id":10,"ResourceId":15}}

服务器响应:

{"data":[{"名称":" secret 任务","Id":10,"StartDate":"2012-09-13T18:00:00+02:00","EndDate ":"2012-09-14T04:00:00+02:00","ResourceId":15,"可调整大小":null,"可拖动":null,"Cls":""}]}

其中 boolean 属性为空。我尝试忽略该字段的 setter ，但没有任何运气。我还必须删除 nullable=false 因为包含此内容时我收到错误:

org.springframework.dao.DataIntegrityViolationException:非空属性引用空值或 transient 值:model.Event.draggable；嵌套异常是 org.hibernate.PropertyValueException:not-null 属性引用 null 或 transient 值:model.Event.draggable

这是我的 MySQL 表定义:

CREATE TABLE IF NOT EXISTS `events` (
  `Id` int(11) NOT NULL AUTO_INCREMENT,
  `Name` varchar(255) DEFAULT NULL,
  `StartDate` varchar(50) DEFAULT NULL,
  `EndDate` varchar(50) DEFAULT NULL,
  `ResourceId` int(11) DEFAULT NULL,
  `Resizable` tinyint(1) DEFAULT NULL,
  `Draggable` tinyint(1) DEFAULT NULL,
  `Cls` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`Id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=12 ;

这是模型代码:

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import org.codehaus.jackson.annotate.JsonAutoDetect;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.annotate.JsonIgnoreProperties;
import org.codehaus.jackson.annotate.JsonIgnore;

@JsonAutoDetect
@JsonIgnoreProperties(ignoreUnknown = true)
@Entity
@Table(name="events")
public class Event {

    @Id
    @GeneratedValue
    @Column(name="Id")
    private int id;

    @Column(name="Name", nullable=false)
    private String name;

    @Column(name="StartDate", nullable=false)
    private String startDate;

    @Column(name="EndDate", nullable=false)
    private String endDate;

    @Column(name="ResourceId", nullable=false)
    private int resourceId;

    @Column(name="Resizable")
    private Boolean resizable;

    @Column(name="Draggable")
    private Boolean draggable;

    @Column(name="Cls", nullable=false)
    private String cls;

    @JsonProperty("Id")
    public int getId() {
        return id;
    }

    @JsonProperty("Id")
    public void setId(int id) {
        this.id = id;
    }

    @JsonProperty("Name")
    public String getName() {
        return name;
    }

    @JsonProperty("Name")
    public void setName(String name) {
        this.name = name;
    }

    @JsonProperty("StartDate")
    public String getStartDate() {
        return startDate;
    }

    @JsonProperty("StartDate")
    public void setStartDate(String start) {
        this.startDate = start;
    }

    @JsonProperty("EndDate")
    public String getEndDate() {
        return endDate;
    }

    @JsonProperty("EndDate")
    public void setEndDate(String end) {
        this.endDate = end;
    }

    @JsonProperty("ResourceId")
    public int getResourceId() {
        return resourceId;
    }

    @JsonProperty("ResourceId")
    public void setResourceId(int id) {
        this.resourceId = id;
    }

    @JsonProperty("Resizable")
    public Boolean getResizable() {
        return resizable;
    }

    @JsonIgnore
    public void setResizable(Boolean resizable) {
        this.resizable = resizable;
    }

    @JsonProperty("Draggable")
    public Boolean getDraggable() {
        return draggable;
    }

    @JsonIgnore
    public void setDraggable(Boolean draggable) {
        this.draggable = draggable;
    }

    @JsonProperty("Cls")
    public String getCls() {
        return cls;
    }

    @JsonProperty("Cls")
    public void setCls(String cls) {
        this.cls = cls;
    }
}

我可以采取什么措施来防止这种行为？

Answer 1

在从 JSON 表示形式反序列化对象时，您明确告诉 Jackson 忽略您提到的两个属性。这:

@JsonIgnore
public void setDraggable(Boolean draggable) {
    this.draggable = draggable;
}

@JsonIgnore
public void setResizable(Boolean resizable) {
    this.resizable = resizable;
}

基本上意味着，从我的 JSON 数据反序列化时忽略这些属性。因此，当您保存对象时，这些属性在数据库中为空。