校验的分类
客户端数据校验 和 服务器端数据校验
客户端数据校验 ,通过JavaScript 完成校验 (改善用户体验,使用户减少出错 )
服务器数据校验 ,通过Java代码 完成校验
struts2 支持校验方式
代码校验(用的很少) :在服务器端通过编写java代码,完成数据校验
配置校验(主流):XML配置校验(主流) 和 注解配置校验
代码校验请求参数
步骤一: 封装数据
步骤二: 实现校验Action ,必须继承ActionSupport 类
步骤三: 覆盖validate方法(validate方法在请求处理方法execute之前执行!)通过代码逻辑判断参数是否有效,如果参数非法,用this.addFieldError(ActionSupport提供)存储校验错误信息,跳转回 input页面
步骤四: 在jsp中 通过 <s:fieldError/>(打印所有错误信息)(或<s:fielderror fieldName="">(打印某个错误信息))显示错误信息
validate方法会对Action中所有业务方法进行校验,如果只想校验某一个方法:用validate方法名()(例如validateRegist())
示例:
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd"> <struts> <package name="default" namespace="/" extends="struts-default"> <action name="regist" class="com.yzu.RegistAction"> <result name="input">/index.jsp</result> </action> </package> </struts>
struts.xml
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@taglib prefix="s" uri="/struts-tags"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP ‘index.jsp‘ starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <s:fielderror/> <form action="${pageContext.request.contextPath}/regist" method="post"> username:<input type="text" name="username"><s:fielderror fieldName="username.message"/><br> password:<input type="password" name="password"><s:fielderror fieldName="password.message"/><br> <input type="submit" value="注册"> </form> </body> </html>
index.jsp
package com.yzu; import com.opensymphony.xwork2.ActionSupport; import com.opensymphony.xwork2.ModelDriven; //使用模型驱动 public class RegistAction extends ActionSupport implements ModelDriven<User> { private User user = new User(); public User getModel() { return user; } @Override public String execute() throws Exception { System.out.println("execute method....."); return null; } @Override public void validate() { System.out.println(11); if (user.getUsername() == null || user.getUsername().trim().length() == 0) { // 说明用户名为空 this.addFieldError("username.message", "用户名不能为空"); } if (user.getPassword() == null || user.getPassword().trim().length() == 0) { this.addFieldError("password.message", "密码不能为空"); } } }
RegistAction
package com.yzu; import java.util.Arrays; import java.util.Date; public class User { private String username; private String password; private int age; private Date birthday; private String[] hobby; private String url; private String email; private String telphone; private String repassword; public String getRepassword() { return repassword; } public void setRepassword(String repassword) { this.repassword = repassword; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getTelphone() { return telphone; } public void setTelphone(String telphone) { this.telphone = telphone; } public String[] getHobby() { return hobby; } public void setHobby(String[] hobby) { this.hobby = hobby; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } @Override public String toString() { return "User [username=" + username + ", password=" + password + ", age=" + age + ", birthday=" + birthday + ", hobby=" + Arrays.toString(hobby) + "]"; } }
User
Xml配置方式数据校验
XML配置方式是主流校验的校验方式,代码校验不适用于大型项目,因为当流程数据复杂时,代码校验的开发量和维护量都会很大
xml配置校验原理 :将很多校验规则代码已经写好,只需要在xml中定义数据所使用校验规则就可以了
配置文件配置要求
位置:xml文件要与action类在同一个包下
名称:action类名-validation.xml
约束: xwork-core-2.3.7.jar 中 xwork-validator-1.0.3.dtd 下
<!DOCTYPE validators PUBLIC "-//Apache Struts//XWork Validator 1.0.3//EN" "http://struts.apache.org/dtds/xwork-validator-1.0.3.dtd">
书写:
1.根元素:<validators>
2.子元素:<field name="属性名称"></field>
3.<field>子元素 :<field-validator type="校验器"> 这个是指定校验器
Struts2提供的校验器有如下这些(xwork-core-2.3.7.jar 中 /com/opensymphony/xwork2/validator/validators/default.xml下)
<validator name="required" class="com.opensymphony.xwork2.validator.validators.RequiredFieldValidator"/> <validator name="requiredstring" class="com.opensymphony.xwork2.validator.validators.RequiredStringValidator"/> <validator name="int" class="com.opensymphony.xwork2.validator.validators.IntRangeFieldValidator"/> <validator name="long" class="com.opensymphony.xwork2.validator.validators.LongRangeFieldValidator"/> <validator name="short" class="com.opensymphony.xwork2.validator.validators.ShortRangeFieldValidator"/> <validator name="double" class="com.opensymphony.xwork2.validator.validators.DoubleRangeFieldValidator"/> <validator name="date" class="com.opensymphony.xwork2.validator.validators.DateRangeFieldValidator"/> <validator name="expression" class="com.opensymphony.xwork2.validator.validators.ExpressionValidator"/> <validator name="fieldexpression" class="com.opensymphony.xwork2.validator.validators.FieldExpressionValidator"/> <validator name="email" class="com.opensymphony.xwork2.validator.validators.EmailValidator"/> <validator name="url" class="com.opensymphony.xwork2.validator.validators.URLValidator"/> <validator name="visitor" class="com.opensymphony.xwork2.validator.validators.VisitorFieldValidator"/> <validator name="conversion" class="com.opensymphony.xwork2.validator.validators.ConversionErrorFieldValidator"/> <validator name="stringlength" class="com.opensymphony.xwork2.validator.validators.StringLengthFieldValidator"/> <validator name="regex" class="com.opensymphony.xwork2.validator.validators.RegexFieldValidator"/> <validator name="conditionalvisitor" class="com.opensymphony.xwork2.validator.validators.ConditionalVisitorFieldValidator"/>
4.<field-validator>子元素:<message>错误信息</message>
5.<field-validator>子元素:<param name="">值</param>用于指定校验器中的参数.
内建校验器介绍
required (必填校验器,要求被校验的属性值不能为null) requiredstring (必填字符串校验器,要求被校验的属性值不能为null,并且长度大于0,默认情况下会对字符串去前后空格) stringlength (字符串长度校验器,要求被校验的属性值必须在指定的范围内,否则校验失败,minLength参数指定最小长度,maxLength参数指定最大长度,trim参数指定校验field之前是否去除字符串前后的空格) regex (正则表达式校验器,检查被校验的属性值是否匹配一个正则表达式,expression参数指定正则表达式,caseSensitive参数指定进行正则表达式匹配时,是否区分大小写,默认值为true) int(整数校验器,要求field的整数值必须在指定范围内,min指定最小值,max指定最大值) double(双精度浮点数校验器,要求field的双精度浮点数必须在指定范围内,min指定最小值,max指定最大值) fieldexpression (字段OGNL表达式校验器,要求field满足一个ognl表达式,expression参数指定ognl表达式,该逻辑表达式基于ValueStack进行求值,返回true时校验通过,否则不通过) email(邮件地址校验器,要求如果被校验的属性值非空,则必须是合法的邮件地址) url(网址校验器,要求如果被校验的属性值非空,则必须是合法的url地址) date(日期校验器,要求field的日期值必须在指定范围内,min指定最小值,max指定最大值)
案例
<?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> <!-- 对username属性进行校验 --> <field name="username"> <!-- 指定username不能为空 --> <field-validator type="requiredstring"> <!-- 错误信息 --> <message>用户名不能为空--------</message> </field-validator> <!-- 长度校验,规定用户名必须在6-10位之间 --> <field-validator type="stringlength"> <param name="maxLength">10</param> <param name="minLength">6</param> <message>用户名必须在${minLength}-${maxLength}位之间</message> </field-validator> </field> <!-- 对age进行校验,规定年龄必须在10-40之间 --> <field name="age"> <field-validator type="int"> <param name="min">10</param> <param name="max">40</param> <message>年龄必须在${min}--${max}之间</message> </field-validator> </field> <!-- 对birthday进行校验 --> <field name="birthday"> <field-validator type="date"> <param name="min">1974-01-01</param> <param name="max">2004-12-31</param> <message>生日必须在${min}年到${max}年之间</message> </field-validator> </field> <!-- 校验邮箱 --> <field name="email"> <field-validator type="email"> <message>邮箱格式不正确</message> </field-validator> </field> <!-- url校验 --> <field name="url"> <field-validator type="url"> <message>url不能这空,类似于http://www.baidu.com</message> </field-validator> </field> <!-- 使用正则 --> <field name="telphone"> <field-validator type="regex"> <param name="regexExpression"><![CDATA[^135[0-9]{8}$]]></param> <message>电话号码必须是135xxxxxxxx</message> </field-validator> </field> <field name="repassword"> <field-validator type="fieldexpression"> <param name="expression"><![CDATA[(password==repassword)]]></param> <message>两次密码输入不一致</message> </field-validator> </field> </validators>
UserAction-regist-validation.xml
自定义校验规则(了解一下就行,实际开发中很少用到自定义校验器)
步骤一: 自定义校验器 必须实现 Validator 接口
通常自定义校验器 继承 ValidatorSupport 和 FieldValidatorSupport
ValidatorSupport 针对不是一个输入字段 (两个密码一致)
FieldValidatorSupport 针对是一个输入字段 (用户名非空)
步骤二: 注册校验器
在工程的src下新建validators.xml文件,引入 xwork-core-2.3.7.jar 中 xwork-validator-config-1.0.dtd
步骤三 :使用校验器
在Action所有包 创建Action类名-validation.xml