The principle of the Struts validation rule:
To implement validation, you need to add a method to the action, such as the Validate () method you want to override. Suppose there is a method for register in action. The default interceptor for struts is executed before the Register method is executed <interceptor name= "validation" class= " Org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor "/> The bottom of this interceptor maintains a map collection, Add the error message to this map and save it when the validation is not passed. Then go to input view to prompt.
1. Code to validate validators for all methods in the action
This action must inherit the Actionsupport class: Because the interceptor needs to be used.
Rewrite the Validate () method.
@Overridepublic void Validate () {//user name non-empty if (User.getusername () ==null| | "". Equals (User.getusername ())) {Super.addfielderror ("username", "user name cannot be empty");} if (User.getpassword () ==null| | User.getpassword (). Length () <8) {super.addfielderror ("password", "Password cannot be empty, and the length is greater than 8 bits");}}Name specification validate+ the method name that needs to be validated, such as Validateregister () then this validator is only valid for the Register method
Verifies that the specified method public void Validateregister () {//user name is non-empty if (User.getusername () ==null| | "". Equals (User.getusername ())) {Super.addfielderror ("username", "user name cannot be empty");} if (User.getpassword () ==null| | User.getpassword (). Length () <8) {super.addfielderror ("password", "Password cannot be empty, and the length is greater than 8 bits");}}XML naming: Actionclassname+validation.xml: Useraction-validation.xml
This XML needs to be placed under a directory similar to the action class.
<?xml version= "1.0" encoding= "UTF-8"?> <! DOCTYPE validators Public "-//apache struts//xwork Validator 1.0.3//en" "http://struts.apache.org/dtds/ Xwork-validator-1.0.3.dtd "> <validators> <field name=" User.username "> <field-validator type=" Requiredstring "> <message> username cannot be empty! </message> </field-validator> </field> <field name= "User.password" > <field-validator type = "requiredstring" > <message> password cannot be empty! </message> </field-validator> <field-validator type= "Stringlength" > <param name= "minlength" >6</param> <param name= "maxlength" >8</param> <message> password at 6 to 8 bits </message> </ field-validator> </field> <field name= "User.date" > <field-validator type= "Date" > <message > Date format is incorrect! </message> </field-validator> </field> <field name= "User.email" > <field-validator type= " Email > <message> email format is incorrect! </message> </field-validaTor> </field> </validators>4.xml validates the method specified in the Action class
XML naming conventions: Actionclassname-actonname-validation.xml such as Useraction-user_register-validation.xml
The XML configuration is the same as 3.
5. Run the configuration:
Struts.xml red font represents configuration global error view
<struts><package name= "user" extends= "struts-default" ><span style= "color: #ff0000;" ><global-results><result name= "Input" >/register.jsp</result></global-results></ Span><action name= "user_*" class= "cn.itcast.action.UserAction" method= "{1}" ><result name= "register" >/index.jsp</result><result name= "List" >/index.jsp</result></action></package> </struts><body> <form action= "${pagecontext.request.contextpath}/user_register" method= "POST" > < Span style= "color: #ff0000;" ><s:fielderror></s:fielderror></span> Username: <input type= "text" name= " User.username "/><br> Password: <input type=" text "name=" User.password "/><br> onboarding Date:< Input type= "text" name= "User.date"/><br> e-mail: <input type= "text" name= "User.email" ><br> <input type= "Submit" value= "Submission"/> </form> </body>Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.
Struts validation rules
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