java - Spring mvc 注释 - javax.el.PropertyNotFoundException : Property 'isOnline' not found on type it. besmart.models.Luce - 但有

Question

大家早上好...

我的 Spring MVC 应用程序运行良好。我在表中添加了一个新字段，更新了我的模型，但我在标题中收到错误。我仅在 ListView 、详细信息页面中收到错误，使用相同的语法，它有效...

我的模型

@Entity
@Table(name="luci", catalog="SMARTPARK", uniqueConstraints = @UniqueConstraint(columnNames = "id_luce"))
public class Luce implements java.io.Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private int idLuce;
    private Integer numeroLuce;
    private String nomeLuce;
    private String descrizione;
    private boolean stato;
    private Client client;
    private boolean isOnline;


public Luce(){}

public Luce(int idLuce, Integer numeroLuce, String nomeLuce, String descrizione, boolean stato, Client client, boolean isOnline){
    this.idLuce = idLuce;
    this.numeroLuce = numeroLuce;
    this.nomeLuce = nomeLuce;
    this.client = client;
    this.descrizione = descrizione;
    this.stato = stato;
    this.isOnline = isOnline;
}

@NotNull
@Id
@GeneratedValue
@Column(name="id_luce", unique = true, nullable = false)
public int getIdLuce() {
    return idLuce;
}

public void setIdLuce(int idLuce) {
    this.idLuce = idLuce;
}


@NotNull
@Column(name="numero_luce", unique = true, nullable = false)
public Integer getNumeroLuce() {
    return numeroLuce;
}

public void setNumeroLuce(Integer numeroLuce) {
    this.numeroLuce = numeroLuce;
}

@NotEmpty
@Size(max=50)
@Column(name="nome_luce", unique = true, nullable = false)
public String getNomeLuce() {
    return nomeLuce;
}

public void setNomeLuce(String nomeLuce) {
    this.nomeLuce = nomeLuce;
}

@ManyToOne
@JoinColumn(name="client")
public Client getClient() {
    return this.client;
}

public void setClient(Client client) {
    this.client = client;
}

@Size(max=255)
@Column(name="descrizione")
public String getDescrizione() {
    return descrizione;
}

public void setDescrizione(String descrizione) {
    this.descrizione = descrizione;
}


@Column(name="stato")
public boolean isStato() {
    return stato;
}

public void setStato(boolean stato) {
    this.stato = stato;
}

@Column(name="is_online")
public boolean isOnline() {
    return isOnline;
}

public void setOnline(boolean isOnline) {
    this.isOnline = isOnline;
}

}

然后在 Controller 中我有一个简单的

@RequestMapping(value = { path }, method = RequestMethod.GET)
    public String listSpots(ModelMap model) {
        List<Luce> luce = luceService.showLights();
        model.addAttribute("luce", luce);

        return path + "/luci";
    }

直到今天早上都有效...... View 部分是

<c:forEach items="${luce}" var="light">
        <tbody>
        <tr>
            <td><div class="list-field">${light.numeroLuce}</div></td>
            <td><div class="list-field">${light.nomeLuce}</div></td>
            <td><div class="list-field">${light.client.nomeClient}</div></td>
            <td><span class="text-success">

            <c:choose>
            <c:when test="${light.stato == true}" ><span class="glyphicon glyphicon-ok-sign"></span></c:when>
                <c:otherwise><span class="text-danger"><span class="glyphicon glyphicon-remove-sign"></span></span></c:otherwise>
                </c:choose>
            </span></td>
            <td><span class="text-success">
            <c:choose>
            <c:when test="${light.isOnline == true}" ><span class="glyphicon glyphicon-ok-sign"></span></c:when>
                <c:otherwise><span class="text-danger"><span class="glyphicon glyphicon-remove-sign"></span></span></c:otherwise>
                </c:choose>
            </span></td>
            <td class="actions"><a class="pull-right" href="<c:url value='/lights/${light.idLuce}' />"><span class="glyphicon glyphicon-edit"></span></a></td>
        </tr>
        </c:forEach>

我刚刚添加了 light.isOnline == true 部分，并收到了错误。只是说，在另一个 View 中我有单个灯的细节，并且它有效..

Answer 1

问题出在 bean 方法 isOnline() 上。

将方法名称更改为 - getIsOnline()，它应该可以正常工作。

当您使用表达式语言时，它会自动附加 get 并将变量的第一个字符大写以获取 getter 方法。您的 bean 中没有 getIsOnline() 方法以及此错误的原因。

编辑:

根据 java bean 变量命名规范，将 boolean 字段的名称更改为 online，然后 isOnline() 方法就可以正常工作。