我正在開發一個Spring Framework項目。對於快速開發過程,我使用Spring Roo(1.3.2)。對於多個實體,我需要存儲創建時間和上次更新的時間。我在Spring Roo教程項目上做了幾個實驗,這是我試圖做的一個實體和方法。Spring Framework的auditng字段(CreatedAt,UpdatedAt)
package com.springsource.roo.pizzashop.domain;
import org.springframework.roo.addon.javabean.RooJavaBean;
import org.springframework.roo.addon.jpa.activerecord.RooJpaActiveRecord;
import org.springframework.roo.addon.tostring.RooToString;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.Date;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.springframework.format.annotation.DateTimeFormat;
@RooJavaBean
@RooToString
@RooJpaActiveRecord
public class Topping {
/**
*/
@NotNull
@Size(min = 2)
private String name;
/**
*/
@Temporal(TemporalType.TIMESTAMP)
@DateTimeFormat(style = "M-")
private Date createdAt;
/**
*/
@Temporal(TemporalType.TIMESTAMP)
@DateTimeFormat(style = "M-")
private Date updatedAt;
@PrePersist
protected void onCreate() {
createdAt= new Date();
}
@PreUpdate
protected void onUpdate() {
updatedAt = new Date();
}
}
當我創建一個對象(Topping)時,它爲createdAt獲取正確的值併爲updatedAt留下「NULL」。完善!這就是它必須的方式!
但是,當我更新對象(Topping)時,它獲取了正確的值updatedAt並失去了createdAt(NULL)的值。
問題是,當我更新對象時,我失去了createdAt的值。
你能告訴我爲什麼我會得到這種行爲嗎?你能幫我解決一個可能的解決方案嗎?
但是,createdAt和updatedAt字段不需要出現在「視圖」(create.jspx,update.jspx)中,所以我將其渲染屬性設置爲false。 這些是用於創建和更新的表單。
create.jspx
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<div xmlns:c="http://java.sun.com/jsp/jstl/core" xmlns:field="urn:jsptagdir:/WEB-INF/tags/form/fields" xmlns:form="urn:jsptagdir:/WEB-INF/tags/form" xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:spring="http://www.springframework.org/tags" version="2.0">
<jsp:directive.page contentType="text/html;charset=UTF-8"/>
<jsp:output omit-xml-declaration="yes"/>
<form:create id="fc_com_springsource_roo_pizzashop_domain_Topping" modelAttribute="topping" path="/toppings" render="${empty dependencies}" z="w4+E4tQPCNRPSYVWPNOBUuf9zNE=">
<field:input field="name" id="c_com_springsource_roo_pizzashop_domain_Topping_name" min="2" required="true" z="GRdEGRLiZ0QLjBH0pTEOZ252BD8="/>
<field:datetime dateTimePattern="${topping_ts_date_format}" field="ts" id="c_com_springsource_roo_pizzashop_domain_Topping_ts" render="false" z="user-managed"/>
<field:datetime dateTimePattern="${topping_updated_date_format}" field="updated" id="c_com_springsource_roo_pizzashop_domain_Topping_updated" render="false" z="user-managed"/>
</form:create>
<form:dependency dependencies="${dependencies}" id="d_com_springsource_roo_pizzashop_domain_Topping" render="${not empty dependencies}" z="bkqRYdlfs3kDAjK51P0O+7NiahE="/>
</div>
update.jspx
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<div xmlns:field="urn:jsptagdir:/WEB-INF/tags/form/fields" xmlns:form="urn:jsptagdir:/WEB-INF/tags/form" xmlns:jsp="http://java.sun.com/JSP/Page" version="2.0">
<jsp:directive.page contentType="text/html;charset=UTF-8"/>
<jsp:output omit-xml-declaration="yes"/>
<form:update id="fu_com_springsource_roo_pizzashop_domain_Topping" modelAttribute="topping" path="/toppings" versionField="Version" z="YGl9ujJNQw182uzoCDgi1FdiafQ=">
<field:input field="name" id="c_com_springsource_roo_pizzashop_domain_Topping_name" min="2" required="true" z="GRdEGRLiZ0QLjBH0pTEOZ252BD8="/>
<field:datetime dateTimePattern="${topping_ts_date_format}" field="ts" id="c_com_springsource_roo_pizzashop_domain_Topping_ts" render="false" z="user-managed"/>
<field:datetime dateTimePattern="${topping_updated_date_format}" field="updated" id="c_com_springsource_roo_pizzashop_domain_Topping_updated" render="false" z="user-managed"/>
</form:update>
</div>