Struts2验证框架无法显示错误提示的解决方案

问题描述:

在教学过程中突然遇到使用struts2的验证框架时,当输入的内容不符合验证规则时,没有进入action(说明验证的拦截器生效了),但是在页面却没有显示错误提示信息,很郁闷调了很久终于发现问题...

部分代码:

<html>
  <body>
    <s:form action="Validate" method="post" >
        <s:textfield label="用户名" name="user.name" />
        <s:textfield label="密码" name="user.pwd"/>
        <s:submit value="提交" />
    </s:form>
  </body>
</html>

index.jsp

public class ValidateAction extends ActionSupport{
    private User user;
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
    public String execute() throws Exception {
        System.out.println("进入action");
        return super.execute();
    }
}

ValidateAction.java

public class User implements Serializable{
    private String name;
    private String pwd;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

User.java

<!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="user.name">
        <field-validator type="requiredstring">
            <param name="trim">true</param>
            <message>请输入用户名</message>
        </field-validator>
    </field>
</validators>

ValidateAction-validation.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
          "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
          "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
    <package name="default" extends="struts-default" namespace="/">
        <action name="Validate" class="com.jb.cdjj.web.actions.ValidateAction">
            <result>/index.jsp</result>
            <result name="input" type="redirect">/validate.jsp</result>
        </action>
    </package>
</struts>

struts.xml

解决方案:

将struts.xml中result的type属性去掉,或使用默认的dispatcher方式.

原理在于验证框架会把错误信息注入到ValueStack的根对象中,而采用redirect重定向方式相当于用户又发起了新的请求,当然无法共享上次请求对应的ValueStack对象.

可以通过struts的debug标签看到这一过程:

posted on 2013-06-19 13:35 kknd713 阅读(556) 评论(0) 编辑收藏举报