java - jsp 不显示 spring validator 错误

Question

我正在使用 spring MVC 创建一个项目。我正在使用 jsr303 验证字段。它工作正常它在控制台中显示字段错误但在 jsp 页面中不显示任何人都可以让我知道我在这里做错了什么吗？

我的 Controller 方法是

@RequestMapping(value="/addCampaign", method = RequestMethod.POST)
    public String processForm(@ModelAttribute(value="Campaign") @Valid CampaignEntity campaignObj,BindingResult result, ModelMap model, Principal principal) {

        validator.validate(campaignObj, result);

        if(result.hasErrors()){         

            System.out.println(result.getErrorCount());
            System.out.println(result.toString());

            CampaignEntity campaignBean = new CampaignEntity();

            Map<String,String> agencies = new LinkedHashMap<String,String>();
            agencies.put("1", "United Stated");
            agencies.put("2", "China");
            agencies.put("3", "Singapore");
            agencies.put("4", "Malaysia");

            model.addAttribute("agencies", agencies);
            model.addAttribute("publishers", agencies);
            model.addAttribute("Campaign", campaignBean);

            return "addCampaign";   
        }else{
            return campaign(model, principal);
        }
    }

在 jsp 中我使用标签显示错误

<form:errors path="*" cssClass="error" />

我的实体类是

package com.nativeunlock.dto;

import java.io.Serializable;
import java.util.Date;

import javax.persistence.*;
import javax.validation.constraints.Digits;
import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.NotEmpty;

import lombok.Data;
import lombok.Getter;
import lombok.Setter;


@SuppressWarnings("serial")
@NamedQueries({
    @NamedQuery(
            name = CampaignEntity.GET_CAMPAIGNS_QUERY,
            query = "from CampaignEntity campaign"
    ),
    @NamedQuery(
            name = CampaignEntity.DELETE_CAMPAIGNS_QUERY,
            query = "DELETE FROM CampaignEntity campaign WHERE campaign.campaign_id = :campaign_id"
    )    
})

@Entity
@Table(name = "campaign")
public class CampaignEntity implements Serializable {

    public static final String GET_CAMPAIGNS_QUERY ="getCampaignList";
    public static final String DELETE_CAMPAIGNS_QUERY ="deleteCampaignList";

    @Id
    @Getter
    @Setter
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "campaign_id", unique = true, nullable = false)
    private int campaign_id;

    @Getter
    @Setter
    @Column(name = "name", unique = true)
    @NotEmpty(message="Name field is mandatory.")
    private String name;


    @Getter
    @Setter
    @Column(name = "no_of_views")
    @NotNull(message="No. of Views field is mandatory.")
    private int no_of_views;

    @Getter
    @Setter
    @Column(name = "video_url") 
    @NotEmpty(message="Video URL field is mandatory.")
    private String video_url;

    @Getter
    @Setter
    @Column(name = "start_date")    
    @NotEmpty(message="Start Date field is mandatory.")
    private String  start_date;

    @Getter
    @Setter
    @Column(name = "end_date")
    @NotEmpty(message="End Date field is mandatory.")
    private String end_date;

    @Getter
    @Setter
    @Column(name = "click_to_play")
    @NotNull(message="Click to play field is mandatory.")
    private int click_to_play;

    @Getter
    @Setter
    @Column(name = "frequency")
    @NotNull(message="Frequency field is mandatory.")
    private int frequency;

    @Getter
    @Setter
    @Column(name = "priority")
    @Digits(fraction = 0, integer = 100)
    @NotNull(message="Priority field is mandatory.")
    private int priority;

    @Getter
    @Setter
    @Column(name = "divice")
    @NotNull(message="Divice field is mandatory.")
    private int divice;

    @Getter
    @Setter
    @Column(name = "operating_system")
    @NotNull(message="Operating system field is mandatory.")
    private int operating_system;

    @Getter
    @Setter
    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "publisher_id")
    @NotEmpty(message="Publisher field is mandatory.")
    private PublisherEntity publishers;

    @Getter
    @Setter
    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "agency_id")
    @NotEmpty(message="Agency field is mandatory.")
    private AgencyEntity agencies;

}

我的 validator 类是

package com.nativeunlock.Validator;

import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;

import com.nativeunlock.dto.CampaignEntity;

@Component
public class CampaignValidator implements Validator{

    @Override
    public boolean supports(Class c) {
        return CampaignEntity.class.isAssignableFrom(c);
    }

    @Override
    public void validate(Object command, Errors errors) {
        CampaignEntity campaignBean = (CampaignEntity)command;
        /*if(!regBean.getPassword().equals(regBean.getRePassword()))
            errors.rejectValue("rePassword","password.notmatch");*/
    }

}

Answer 1

问题在于，通过添加模型属性 model.addAttribute("Campaign", campaignBean);，您将从模型中删除绑定(bind)错误。

绑定(bind)错误绑定(bind)到经过验证的实例。如果您将断点设置到方法内的第一行并检查模型，您将看到一个带有键 Campaign 的已验证对象，还有一个带有键 org.springframework 的绑定(bind)错误对象.validation.BindingResult.Campaign

当您进一步移动并到达您在“Campaign”键下向模型添加新实例时，请注意绑定(bind)错误将从模型中删除，因为它们绑定(bind)的实例是不再存在，这就是您在 JSP 中看不到它们的原因。

删除 model.addAttribute("Campaign", campaignBean); 或更改 key ，您应该会看到绑定(bind)错误。

也不是说您不需要手动调用 validator.validate(campaignObj, result); @Valid 会为您调用验证