Struts2系列之动作类

编写动作类的三种方式

1.动作类的第一种:普通的javaBean,没有任何继承 POJO(Plan Old Java Object)

Action类:

/** * Created by dllo on 17/7/4. * 动作类的第一种 * POJO:Plan Old Java Object */public class DemoAction1 {    //动作方法:    public String demo1(){        return "success";    }}

struts.xml

<struts> <package name="actions" extends="struts-default">        <action name="demo1" class="com.wangyjie.struts.actions.DemoAction1" method="demo1">            <result name="success">/success.jsp</result>        </action>    </package></struts>

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2. 动作类第二种 实现Action接口

Action类

/** * Created by dllo on 17/7/4. * 动作类的第二种 * * 实现Action的接口 */public class DemoAction2 implements Action{    @Override    public String execute() throws Exception {        return SUCCESS;    }}

struts.xml

 <package name="action2" extends="struts-default">        <action name="demo2" class="com.wangyjie.struts.actions.DemoAction2" method="execute">            <result name="success">/success.jsp</result>        </action>    </package>

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3. 动作类第三种:继承ActionSupport[推荐使用]

//Action类

/** * Created by dllo on 17/7/4. * 动作类的第三种: [推荐使用] * 继承于ActionSupport */public class DemoAction3 extends ActionSupport{    public String www(){        return ERROR;    }}

//struts.xml

  <package name="action3" extends="struts-default">        <action name="demo3" class="com.wangyjie.struts.actions.DemoAction3" method="www">            <result name="error">/error.jsp</result>        </action>    </package>

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动作类中的动作方法编写要求

public String XXX(){}

使用通配符配置action

在配置元素时,允许在指定name属性时,使用模式字符串(“*”代表一个或多个字符)

为了防止写一些这样重复性的东西 出现了通配符

  <action name="delete_Customer" class="com.wangyjie.struts.wildcard.CustomerAction" method="deleteCustomer">            <result name="success">/deleteCustomer.jsp</result>        </action>        <action name="edit_Customer" class="com.wangyjie.struts.wildcard.CustomerAction" method="editCustomer">            <result name="success">/editCustomer.jsp</result>        </action>        <action name="query_Customer" class="com.wangyjie.struts.wildcard.CustomerAction" method="queryCustomer">            <result name="success">/queryCustomer.jsp</result>

 <!--通配符 类似我们之前学过的占位符一样-->        <action name="*Customer" class="com.wangyjie.struts.wildcard.CustomerAction" method="{1}Customer">            <result name="success">{1}Customer.jsp</result>        </action>        <action name="*_*" class="com.wangyjie.struts.wildcard.{2}Action" method="{1}{2}">            <result name="success">{1}{2}.jsp</result>        </action>

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Action访问ServletAPI

方式一:ServletActionContext

HttpServletRequest request = ServletActionContext.getRequest();

实现ServletRequestAware接口

 private HttpServletRequest request;//重写方法    @Override    public void setServletRequest(HttpServletRequest httpServletRequest) {        this.request = httpServletRequest;    }    public HttpServletRequest getRequest(){        return request;    }