1.在maven工程下添加需要导入的jar包节点
<dependencies>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.3.24</version>
</dependency>
<dependency>
<groupId>org.apache.struts.xwork</groupId>
<artifactId>xwork-core</artifactId>
<version>2.3.24</version>
</dependency>
</dependencies>
2.web-inf文件下配置web.xml节点
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
3.构建index.jsp页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ page isELIgnored="false" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<s:fielderror value="error"></s:fielderror>
<s:actionerror/>
<s:property value="ret"/>
<s:debug/>
<form action="testAction" method="post">
用户名：<input name="uname"/><br/>
密码：<input name="upwd"/><br/>
<input type="submit"/>
</form>
</body>
</html>
4.创建TestAction
方法一：实现Action接口
public String execute() throws Exception {
System.out.println("action");
if (this.getUname().equals("")) {
addFieldError("error", "用户名为空值");
addActionError("actionerror");
return "ret1";
}else if (this.getUpwd().equals("")){
addFieldError("error", "密码为空值");
return "ret1";
}
return "ret1";
}
方法二：继承ActionSupport类
public void validate() {
System.out.println("actionsuppo");
if (this.getUname().equals("")) {
addFieldError("error", "用户名为空值");
addActionError("actionerror");
}else if (this.getUpwd().equals("")){
addFieldError("error", "密码为空值");
}
}
5.配置struts.xml文件
<constant name="struts.enable.DynamicMethodInvocation" value="false"/>
<constant name="struts.devMode" value="true"/>
<package name="default" namespace="/" extends="struts-default">
<action name="testAction" class="action.TestAction">
<result name="input">index.jsp</result>
</action>
</package>
6.测试页面
但用户名为空时
但密码为空时
