一. ActionSupport是个工具类,他实现了Action, Validatable等接口, Validatable提供validate()方法进行数据验证.Action只要继承ActionSupport类,重写validate()方法就可以进行数据验证
二. 校验的流程
首先,Struts框架对输入数据进行类型转换,然后再进行数据校验,如果类型转换与数据校验都没有错误发生, 就进入execute(),否则请求将被转发到input视图
三. 注册实例
首先新建RegistAcion.java
- package com;
- import java.util.Date;
- import com.opensymphony.xwork2.ActionSupport;
- public class RegistAction extends ActionSupport {
- private String userName;
-
- private Integer age;
-
- private Date birthday;
-
- public String getUserName() {
- return userName;
- }
- public void setUserName(String userName) {
- this.userName = userName;
- }
- public Integer getAge() {
- return age;
- }
- public void setAge(Integer age) {
- this.age = age;
- }
- public Date getBirthday() {
- return birthday;
- }
- public void setBirthday(Date birthday) {
- this.birthday = birthday;
- }
- @Override
- public String execute() throws Exception {
- System.out.println("注册成功");
- return SUCCESS;
- }
- @Override
- public void validate() {
- if("".equals(userName)){
- addFieldError("userName", "username is empty");
- }
- if(null != age){
- if(1 > age || 150 < age){
- addFieldError("age", "age invalid");
- }
- }
- }
- }
package com;
import java.util.Date;
import com.opensymphony.xwork2.ActionSupport;
public class RegistAction extends ActionSupport {
private String userName;
private Integer age;
private Date birthday;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
@Override
public String execute() throws Exception {
System.out.println("注册成功");
return SUCCESS;
}
@Override
public void validate() {
if("".equals(userName)){
addFieldError("userName", "username is empty");
}
if(null != age){
if(1 > age || 150 < age){
addFieldError("age", "age invalid");
}
}
}
}
配置Action
- <action name="regist" class="com.RegistAction">
- <result name="success">/welcome.jsp</result>
- <result name="input">/regist.jsp</result>
- </action>
<action name="regist" class="com.RegistAction">
<result name="success">/welcome.jsp</result>
<result name="input">/regist.jsp</result>
</action>
接着是注册页面和注册成功页面
regist.jsp
- <body>
- <form action="regist.action" method="post">
- <s:fielderror></s:fielderror>
- <table><tr>
- <td>userName:</td>
- <td>
- <input type="text" name="userName">
- </td>
- </tr>
- <tr>
- <td>age:</td>
- <td>
- <input type="text" name="age">
- </td>
- </tr>
- <tr>
- <td>birthday:</td>
- <td>
- <input type="text" name="birthday">
- </td>
- </tr>
- <tr>
- <td colspan="2">
- <s:submit value="注册"></s:submit>
- </td>
- </tr>
- </form>
- </body>
<body>
<form action="regist.action" method="post">
<s:fielderror></s:fielderror>
<table><tr>
<td>userName:</td>
<td>
<input type="text" name="userName">
</td>
</tr>
<tr>
<td>age:</td>
<td>
<input type="text" name="age">
</td>
</tr>
<tr>
<td>birthday:</td>
<td>
<input type="text" name="birthday">
</td>
</tr>
<tr>
<td colspan="2">
<s:submit value="注册"></s:submit>
</td>
</tr>
</form>
</body>
如果不输入userName, age输入为abc,会提示
Invalid field value for field "age".
username is empty
1. 其中Invalid field value for field "age" 信息是struts2通过内置的类型转换器进行类型转换时,如果不能成功转换, struts2框架自动生成一条错误信息,并将该错误信息放到addFieldError里面,这种默认的输出信息格式是在 xwork-2.0.4.jar中定义的. com/opensymphony/xwork2/xwork-messages.properties文件中有一条xwork.default.invalid.fieldvalue=Invalid field value for field "{0}".
2. 这是一种全局的错误提示方式,整个系统中只要是字段类型转换错误都会这样提示,我们也可以改变这种输出格式,只要在全局的国际资源文件中重写xwork.default.invalid.fieldvalue就可以了.
实现方式:
在struts.xml中加入<constant name="struts.custom.i18n.resources" value="messageResource"></constant> (此处i18n,不是l,是1)
或者也可以在struts.properties中加入struts.custom.i18n.resources=messageResource
指定国际化资源文件名为messageResource. Properties
新建messageResource. Properties资源文件并添加数据xwork.default.invalid.fieldvalue={0} failure
修改之后字段类型转换错误提示为 : {0} failure
3 所有的类型转换失败后,struts2会将基本类型设置为0,对象类型设置为null,这里的age的类型为Integer,当类型转换失败age值为null,如果age的类型为int,那么转换失败后值为0
4.这种提示信息不够友好,也可以定义局布的提示信息,为每一个Action新建一个properties文件,文件名为XXX.properties(Action名.properties)
实现方式:新建RegistAction.properties并添加
invalid.fieldvalue.age=age error
invalid.fieldvalue.birthday=birthday error
其中age和birthday分别为字段的名称
四.
Struts2也提供类似BaseDispatchAction的功能
- package com;
- import com.opensymphony.xwork2.ActionSupport;
- public class Regist2Action extends ActionSupport {
- private String userName;
-
- public String getUserName() {
- return userName;
- }
- public void setUserName(String userName) {
- this.userName = userName;
- }
- public String regist() throws Exception {
- System.out.println("注册成功-regist");
- return SUCCESS;
- }
-
- public void validateRegist() {
- if(userName.equals("")){
- addFieldError("userName", "请输入用户名-registValidate");
- }
- }
- }
package com;
import com.opensymphony.xwork2.ActionSupport;
public class Regist2Action extends ActionSupport {
private String userName;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String regist() throws Exception {
System.out.println("注册成功-regist");
return SUCCESS;
}
public void validateRegist() {
if(userName.equals("")){
addFieldError("userName", "请输入用户名-registValidate");
}
}
}
<action name="regist2" class="com.Regist2Action" method="regist">
<result name="success">/welcome.jsp</result>
<result name="input">/regist2.jsp</result>
</action>
指定了method为regist,当请求时会执行regist(),不会再去执行默认的execute()方法了,
validateRegist()方法是专门针对regist校验的.(格式为validate+方法名)