Struts2 自定义Result返回类型

直接上代码：

自定义类型代码如下：

import java.io.OutputStream;


import javax.servlet.http.HttpServletResponse;


import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.StrutsResultSupport;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;


import com.opensymphony.xwork2.ActionInvocation;


public class ChartResult extends StrutsResultSupport {


/**
     * 
     */
private static final long serialVersionUID = 4199494785336139337L;


// 图片宽度
private int width;
// 图片高度
private int height;
// 图片类型 jpg,png
private String imageType;


@Override
protected void doExecute(String arg0, ActionInvocation invocation)
throws Exception {
JFreeChart chart = (JFreeChart) invocation.getStack()
.findValue("chart");
HttpServletResponse response = ServletActionContext.getResponse();
OutputStream os = response.getOutputStream();


if ("jpeg".equalsIgnoreCase(imageType)
|| "jpg".equalsIgnoreCase(imageType))
ChartUtilities.writeChartAsJPEG(os, chart, width, height);
else if ("png".equalsIgnoreCase(imageType))
ChartUtilities.writeChartAsPNG(os, chart, width, height);
else
ChartUtilities.writeChartAsJPEG(os, chart, width, height);


os.flush();


}


public void setHeight(int height) {
this.height = height;
}


public void setWidth(int width) {
this.width = width;
}


public void setImageType(String imageType) {
this.imageType = imageType;
}
}

其中chart为Action中变量：

public class JFreeChartAction extends ActionSupport {
// 供ChartResult调用->ActionInvocation.getStack().findValue("chart")
private JFreeChart chart;

 ........

}

Struts.xml文件：

<package name="jFreeChartDemonstration" extends="struts-default"
        namespace="/jfreechart">
        <!-- 自定义返回类型 -->
        <result-types>
            <result-type name="chart" class="com.jfreechart.ChartResult"></result-type>
        </result-types>


<!-- 各种图形 -->
        <action name="JFreeChart-*" class="com.jfreechart.JFreeChartAction" method="{1}">
              <result type="chart"> 
                   <param name="width">400</param>
                   <param name="height">300</param>
                   <param name="imageType">jpg</param>
            </result>
        </action>
    </package>