Struts2 文件下载

<package name="defaultPackage" extends="struts-default">
		<!--配置下载Action入口-->
		<action name="download" class="com.johnnian.DownloadAction" >
			<!--stream 是文件下载的时候专用的-->
			<result name="success" type="stream">
				<!--文件下载的类型-->
				<param name="contentType">${contentType}</param>
				<!--文件下载方式分为：-->
				<param name="contentDisposition">inline;filename="${filename}"</param>
				<!--文件下载入口-->
				<param name="inputName">testDownload</param>
				<param name="bufferSize">1024</param>
			</result>
		</action>
	</package>

public class TicketDownloadAction extends ActionSupport {

	private String testParam; 
	
	private String filename;//文件名
	private String contentType;//文件类型
	

	/**
    *  下载处理方法： 
    */
	public InputStream getTestDownload() {
		
        // 直接获取参数
        String params = getTestParam();

		String path = "/Users/Johnnian/tmp/123.png";
		this.setFilename("123.png");
		this.setContentType("image/png");
		
		InputStream inputStream = null;
		try {
			inputStream = new FileInputStream(path);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	
		//可以应答任何继承 InputStream 的类实例
		return inputStream;
			
	}
	
	//---------------------------------
	//			Gettter & Setter
	//---------------------------------

	public String getTestParam() {
		return testParam;
	}

	public void setTestParam(String testParam) {
		this.testParam = testParam;
	}

	public String getFilename() {
		return filename;
	}

	public void setFilename(String filename) {
		this.filename = filename;
	}

	public String getContentType() {
		return contentType;
	} 
	
	public void setContentType(String contentType) {
		this.contentType = contentType;
	}

}

<a href="http://127.0.0.1:8080/posbox/downloadTicket.jhtml?testParam=12345678"> 点击下载 </a>