Question

我正在尝试使用JSTL在动态生成的表的每一行上获取一个删除按钮。使用forEach方法生成表时，所有数据库字段都没有问题。当我尝试对ID（整数和表主键）执行相同操作时，它会给出错误＆＃34;财产＆＃39; cars_id＆＃39;在logon.Car＆＃34;类型上找不到。可以使用resultList.get（1）.getID（）从结果列表中提取它们，并且它在屏幕上打印到jsp页面没问题。

这里有什么我想念的吗？任何IDeas？

我的JSP：

 <% 
List<Car> resultList = new ArrayList<Car>();
resultList=(List<Car>)request.getAttribute("ResultList");

%>
<table border="1">
<thead title="Current Cars"/>
<tr><th>Make:</th><th>Model:</th><th>Year:</th><th>Colour:</th><th>Information:</th></tr>
<tbody>
<c:forEach items="${ResultList}" var="car">
<tr>
    <td>${car.carMake}</td>
    <td>${car.model}</td>
    <td>${car.carYear}</td>
    <td>${car.carColour}</td>
    <td>${car.information}</td>
  <td>
        <form action="CarServlet" method="get">
            <input type="hidden" name="carId" value="${car.cars_id}" />
            <input type="submit" value="Remove" name="remove">
        </form>
    </td> 
</tr>
</c:forEach>
</tbody>
</table>

我的Car.java

@Entity
@Table(name = "cars")
public class Car {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int cars_id;

@Column(name = "cars_make")
private String carMake;

@Column(name = "year")
private String carYear;

@Column(name = "colour")
private String carColour;

@Column(name="information")
private String information;

@Column(name="model")
private String carModel;

//NOTE:"user_id" below in (@JoinColumn(name="user_id"))...is the name
//of the field in my sql that corresponds to id from User table 

    @ManyToOne(fetch = FetchType.LAZY)
@JoinColumns({ @JoinColumn(name = "user_id", referencedColumnName="id") })
private User user;



public User getUser() {
    if (user == null) {
        user = new User();
    }
    return user;
 }

public void setUser(User user) {
    this.user = user;
}

    public int getCar_id() {
    return cars_id;
}

public void setCar_id(int cars_id) {
    this.cars_id = cars_id;
}

public String getCarMake() {
    return carMake;
}

public void setCarMake(String carMake) {
    this.carMake = carMake;
}

public String getModel() {
    return carModel;
}

public void setModel(String carModel) {
    this.carModel = carModel;
}

public String getCarYear() {
    return carYear;
}

public void setCarYear(String carYear) {
    this.carYear = carYear;
}

public String getCarColour() {
    return carColour;
}

public void setCarColour(String carColour) {
    this.carColour = carColour;
}

public String getInformation() {
    return information;
}

public void setInformation(String information) {
    this.information = information;
}
 }

Answer 1

${car.cars_id}应为${car.car_id}

EL字段名称应与bean方法名称匹配，而不是类字段本身。

使用JSTL提取主键

1 个答案: