SSH学习-struts2的result类型

        <result-types>
            <result-type name="chain" class="com.opensymphony.xwork2.ActionChainResult"/>
            <result-type name="dispatcher" class="org.apache.struts2.dispatcher.ServletDispatcherResult" default="true"/>
            <result-type name="freemarker" class="org.apache.struts2.views.freemarker.FreemarkerResult"/>
            <result-type name="httpheader" class="org.apache.struts2.dispatcher.HttpHeaderResult"/>
            <result-type name="redirect" class="org.apache.struts2.dispatcher.ServletRedirectResult"/>
            <result-type name="redirectAction" class="org.apache.struts2.dispatcher.ServletActionRedirectResult"/>
            <result-type name="stream" class="org.apache.struts2.dispatcher.StreamResult"/>
            <result-type name="velocity" class="org.apache.struts2.dispatcher.VelocityResult"/>
            <result-type name="xslt" class="org.apache.struts2.views.xslt.XSLTResult"/>
            <result-type name="plainText" class="org.apache.struts2.dispatcher.PlainTextResult" />
        </result-types>

  <package name="demo" namespace="/hello" extends="struts-default">
    <!-- 当和Spring整合后，class不需要写全名，使用bean id即可，默认为类名首字母小写 -->
    <action name="helloStruts" class="helloStruts"> 
       <result name="success">
         /WEB-INF/helloStruts.jsp
       </result>
    </action>
  </package>

  <!-- result类型测试 -->
  <package name="result" namespace="/result" extends="struts-default">
    <action name="helloStruts" class="helloStruts">
      <result name="success">
        /WEB-INF/helloStruts.jsp
      </result>      
    </action>       
       <!-- 用户提交不同的数字，实现dispatcher，redirectAction，redirect三种功能 -->
       <action name="sw" class="switchAction" method="doSwitch">
         <!-- 返回1，实现转发 -->
         <result name="1" type="dispatcher">
           /WEB-INF/helloStruts.jsp
         </result>
         <!-- 返回2，实现重定向到其他action -->
         <!-- 转发到内部的action -->
         <result name="2" type="redirectAction">
           helloStruts
         </result>
         <!-- 转发到其他的action -->
         <result name="3" type="redirectAction">
           <param name="namespace">/hello</param>
           <param name="actionName">helloStruts</param>
         </result>
         <!-- 转发到URL -->
         <result name="4" type="redirect">
           https://www.cnblogs.com/youngchaolin/
         </result>
       </action>      
       
  </package>

package Controller;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;

/**
 * 用户从浏览器提交不同的数字，得到不同的result处理结果
 * @author yangchaolin
 *
 */
@Controller("switchAction")
@Scope("prototype")
public class switchAction {
    
    //属性，用于接受用户提交的数字
    private int num;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
    
    //具体自定义执行方法
    //方法里写参数会报错，不写参数就OK
    public String doSwitch() {
          String numStr=Integer.toString(num);
          System.out.println("用户提交的数字为："+numStr);
          return numStr;
    }

}

         <result type="redirect">
           <param name="location">
             https://www.cnblogs.com/youngchaolin/
           </param>
         </result>

       <!-- result类型指定为stream，浏览器向服务端请求一张图片，并显示在网页 -->
       <action name="image" class="imageAction">
         <result name="success" type="stream">
           <param name="contentType">image/png</param>
           <param name="inputName">image</param>
           <param name="contentDisposition">attachment;filename="test.png"</param>
           <param name="bufferSize">1024</param>
         </result>
       </action>

package Controller;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;

/**
 * 服务端给浏览器发送图片
 * @author yangchaolin
 *
 */
@Controller("imageAction")
@Scope("prototype")
public class imageAction {
    
    //属性
    //属性名需要和struts.xml配置文件中inputName属性值一致
    InputStream image;

    //浏览器从服务器获取图片需要设置get方法，使用工具一般两个都配置了
    public InputStream getImage() {
        return image;
    }

    public void setImage(InputStream image) {
        this.image = image;
    }
    
    //具体执行方法
    public String execute() throws IOException {
        //准备画布
        BufferedImage img=new BufferedImage(200,200,BufferedImage.TYPE_INT_RGB);
        //准备画笔
        Graphics2D g=img.createGraphics();
        //画图
        g.setColor(Color.CYAN);
        Font font=new Font("微软雅黑",Font.BOLD,20);
        g.setFont(font);
        g.drawString("Hello Struts2", 30, 100);        
        //将图片转换成字节数组
        ByteArrayOutputStream out=new ByteArrayOutputStream();
        ImageIO.write(img, "png", out);
        byte[] imgByte=out.toByteArray();
        //将字节数组作为参数，传入inputStream构造方法
        image=new ByteArrayInputStream(imgByte);
        return "success";
    }

}