自定义结果视图

1）编写一个类，直接或间接实现com.opensymphony.xwork2.Result 接口，一般是继承于org.apache.struts2.dispatcher.StrutsResultSupport类。然后实现doExecute()方法，输出结果即可。

public class CaptchaResults extends StrutsResultSupport{
   @Override  //   输出结果即可
   protected void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
    ValidateCode va = new ValidateCode(120,130,4,100);
    BufferedImage image =  va.getBuffImg();
    // 输出验证码
    HttpServletResponse response = ServletActionContext.getResponse();
    ImageIO.write(image, "jpeg", response.getOutputStream());
   }
}

2)声明结果类型才能使用

<package name="p1" extends="struts-default">
  <!-- 结果类型定义 -->
  <result-types>
     <result-type name="captcha" class="com.pangu.results.CaptchaResults"></result-type>
  </result-types>
  <action name="captcha">
     <result name="success" type="captcha">
        <param name="width">200</param>
        <param name="height">200</param>
        <param name="numConut">4</param>
        <param name="grLineNum">200</param>
     </result>
  </action>
 </package>