动态挪用Action与Action中要领(一)

Struts1提供了DispatchAction 实现一个Action中名含多个业务逻辑

此刻我们利用Struts2 也可实现现样的结果,是利用通配符来实现的.

struts.xml 文件中,常用

<action /> 的name ,class,method 三个属性都支持通配符

<resutl/> 也支持通配符

Xml代码

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="struts2" extends="struts-default">
<action name="*Action_*" class="ssh.org.web.{1}Action" method="{2}">
<result name="success">/user/success.jsp</result>
<result name="input">/user/user.jsp</result>
</action>
</package>
</struts>

针对上面的设置,如果我拉的URL 是:http://localhost/struts/UserAction_addUser .action

UserAction_addUser 与*Action_* 匹配　 ,第一个* 是User,第二个*是addUser,

{1} 的值为 User,{2}的值为addUser ,区分巨细写.

class="ssh.org.web.{1}Action"　 赋值后是,由User 替代{1}

method="{2}" 赋值后是,由addUser 替代{2}

从而实现动态的找到Action 与找个Action中的要领.

个中一个Action代码: 类名是UaerAction,个中有addUser()要领

与URL http://localhost/struts/UserAction_addUser .action　 相匹配,模式为*Action_*

Java代码

package ssh.org.web;
import java.util.Date;
import java.util.List;
import com.opensymphony.xwork2.ActionSupport;
public class UserAction extends ActionSupport
{
private static final long serialVersionUID = 1L;
private String username;
private int age;
private Date birthday;
private List<String> aihao;
public String addUser() throws Exception
{
//添加用户
return "success";
}
public void validateAddUser()
{
if (null == username || "".equals(username))
{
addFieldError("username","用户名不能为空");
}
System.out.println("validateAddUser() 验证要领 ");
}
public String getUserList()
{
//取得所有用户
return "success";
}
public void validateGetUserList()
{
//验证要明确...
System.out.println("validateAddUser() 验证要领 ");
}
public String getUsername()
{
return username;
}
public void setUsername(final String username)
{
this.username = username;
}
public int getAge()
{
return age;
}
public void setAge(final int age)
{
this.age = age;
}
public Date getBirthday()
{
return birthday;
}
public void setBirthday(final Date birthday)
{
this.birthday = birthday;
}
public List<String> getAihao()
{
return aihao;
}
public void setAihao(final List<String> aihao)
{
this.aihao = aihao;
}
}

<resutl/> 也支持通配符,

struts.xml文件 一例子:

Xml代码

<action name="page_*" class="ssh.org.web.HrefAction" >
<result name="success">{1}.jsp</result>
</action>

最后在说一说优先级的问题

通配符匹配方法 ,当我们写多个<action name="*"　 …/> 时,意思就是你的URL大概与多个<action name="*"　 …/>匹配上,先执行那一个?

答: 按书写的先后顺序,先找到哪个,就执行哪个.