struts2的校验-宣言校验和编程校验
struts2的校验-声明校验和编程校验
对于用户输入的信息,web应用程序通常会进行有效性和逻辑性等方面的校验,struts2对此提供了基于xwok的声明式校验和编程式校验。
一、声明式校验需要一个xml文件,这个文件提供哪些字段需要校验,应用什么规则。文件名格式:actionname-validation.xml,如果action有多个方法,要为每个方法定义规则,则需要添加方法名,如actionname-methodname-validation.xml。此例包括一个action,一个xml文件(与action在同一目录下),两个jsp文件,其他还有在struts.xml中的配置信息。
action代码如下:
package data.validator; import com.opensymphony.xwork2.ActionSupport; public class ValidateableAction extends ActionSupport { private String userName; private String password; public String testValidate()throws Exception { return ActionSupport.SUCCESS; } public String getUserName() { return userName; } public String getPassword() { return password; } public void setUserName(String userName) { this.userName = userName; } public void setPassword(String password) { this.password = password; } }
校验规则文件ValidateableAction-validation.xml,其中包含两个字段,校验类型都是‘requiredstring’:
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd"> <validators> <field name="userName"> <field-validator type="requiredstring"> <message>You must enter a valid name</message> </field-validator> </field> <field name="password"> <field-validator type="requiredstring"> <message>You must enter a valid password</message> </field-validator> </field> </validators>
struts.xml文件添加如下action信息:
<action name="testValidate" class="data.validator.ValidateableAction" method="testValidate"> <result name="input">/dataValid/validate.jsp</result> <result name="success">/dataValid/success.jsp</result> </action>
validate.jsp文件:
<%@ taglib prefix="s" uri="/struts-tags" %> <html> <head> <style type="text/css"> .errorMessage{ color:red; } </style> </head> <body> <s:form action="testValidate"> <s:textfield name="userName" label="userName"></s:textfield> <s:password name="password" label="password"></s:password> <s:submit/> </s:form> </body> </html>
success.jsp文件:
<html> <head> </head> <body> <div> You have entered valid userName and password. </div> </body> </html>
二、使用声明式校验,对于一些数据完整、有效等,比较方便,并且代码无侵入,但是要进行逻辑性强的,则需要编程校验。struts2提供了Validateable接口,如果是Pojo action,实现这个接口,在validate()方法中编写校验逻辑,struts2会自动运行这个方法。上面这个例子,action继承了struts的ActionSupport,就已经实现了Validateable接口,所以只需要覆盖validate()方法即可,如下代码:
package data.validator; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import com.opensymphony.xwork2.ActionSupport; public class ValidateableAction extends ActionSupport { private String userName; private String password; private static List dbusers = new ArrayList(); static{ dbusers = Arrays.asList(new String[]{"xiaowang","xiaoliu"}); } public String testValidate()throws Exception { return ActionSupport.SUCCESS; } public void validate(){ if(dbusers.contains(userName)){ addFieldError("userName","userName have been used."); } } public String getUserName() { return userName; } public String getPassword() { return password; } public void setUserName(String userName) { this.userName = userName; } public void setPassword(String password) { this.password = password; } }
这样,使用编程式校验就可以实现逻辑性和业务相关性较强的校验规则了。