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工作原理

利用strust2的action通配对保护的图片得到后返回流文件，如果目录下没有找到图片，则返回未找到图片提示；对请求的IP进行对比，如果不在允许的IP列表时则返回没有权限的图片。

首先在struts.properties文件中添加查询后缀，struts的默认为action，可以添加多个，中间用“，”隔开

struts.i18n.encoding = UTF-8struts.action.extension = html,jpgstruts.devMode=truestruts.custom.i18n.resources=messageResourcestruts.locale=zh_CNstruts.multipart.saveDir=javax.servlet.context.tempdirstruts.ui.theme=simplestruts.enable.DynamicMethodInvocation=true

添加action类Test，其中有两个属性：String contentType，InputStream bis，前者是制定输出的流文件类型，后一个是文件流

package test.com.eca.service;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.FileInputStream;import java.io.IOException;import java.util.regex.Matcher;import java.util.regex.Pattern;import javax.servlet.http.HttpServletRequest;import main.com.eca.util.JsonUtil;import org.apache.struts2.ServletActionContext;import org.nail.common.BaseAction;import com.opensymphony.xwork2.Action;public class Test extends BaseAction {	private BufferedOutputStream bos = null;	private BufferedInputStream bis = null;	private String imgPath;	private String contentType;	public String testImg() throws Exception {		HttpServletRequest request = ServletActionContext.getRequest();		System.out.println("request.getHeader(\"user-agent\")"				+ request.getHeader("user-agent"));		System.out.println("请求来源于浏览器 ："+BrowseTool.checkBrowse(request.getHeader("user-agent")));		// 访问图片后缀		StringBuffer requestUrl = request.getRequestURL();		String fileType = requestUrl.substring(requestUrl.lastIndexOf("."));		// 得到访问的IP		String reqIp = IpUtils.getIpAddr(request);		System.out.println("img : " + imgPath + fileType);		System.out.println("ip : " + reqIp);		// 的到允许的IP的Map		if ("127.0.0.1".equals(reqIp)) {			bis = new BufferedInputStream(new FileInputStream(					"D:/images/no_acc_image.jpg"));			return Action.SUCCESS;		}		// 判断是否有权限		try {			try {				bis = new BufferedInputStream(new FileInputStream("D:/images/"						+ imgPath + fileType));			} catch (Exception e) {				// e.printStackTrace();				bis = new BufferedInputStream(new FileInputStream(						"D:/images/no_image.jpg"));			}		} catch (final IOException e) {			e.printStackTrace();		} catch (Exception e) {			e.printStackTrace();		}		return Action.SUCCESS;	}	public static void main(String[] args) throws Exception {		System.out.println("abcds".substring("abcds".indexOf("c")));	}	public BufferedOutputStream getBos() {		return bos;	}	public void setBos(BufferedOutputStream bos) {		this.bos = bos;	}	public BufferedInputStream getBis() {		return bis;	}	public void setBis(BufferedInputStream bis) {		this.bis = bis;	}	public String getImgPath() {		return imgPath;	}	public String getContentType() {		return contentType;	}	public void setContentType(String contentType) {		this.contentType = contentType;	}	public void setImgPath(String imgPath) {		this.imgPath = imgPath;	}}/** *  * @author cc 20120307 */class BrowseTool {	private final static String IE5_5 = "MSIE 5.5";	private final static String IE9 = "MSIE 9.0";	private final static String IE8 = "MSIE 8.0";	private final static String IE7 = "MSIE 7.0";	private final static String IE6 = "MSIE 6.0";	private final static String MAXTHON = "Maxthon";	private final static String QQ = "QQBrowser";	private final static String GREEN = "GreenBrowser";	private final static String SE360 = "360SE";	private final static String FIREFOX = "Firefox";	private final static String OPERA = "Opera";	private final static String CHROME = "Chrome";	private final static String SAFARI = "Safari";	private final static String OTHER = "其它";	public static String checkBrowse(String userAgent) {		if (regex(OPERA, userAgent)) {			return OPERA;		} else if (regex(CHROME, userAgent)) {			return CHROME;		} else if (regex(FIREFOX, userAgent)) {			return FIREFOX;		} else if (regex(SAFARI, userAgent)) {			return SAFARI;		} else if (regex(SE360, userAgent)) {			return SE360;		} else if (regex(GREEN, userAgent)) {			return GREEN;		} else if (regex(QQ, userAgent)) {			return QQ;		} else if (regex(MAXTHON, userAgent)) {			return MAXTHON;		} else if (regex(IE9, userAgent)) {			return IE9;		} else if (regex(IE8, userAgent)) {			return IE8;		} else if (regex(IE7, userAgent)) {			return IE7;		} else if (regex(IE6, userAgent)) {			return IE6;		} else if (regex(IE5_5, userAgent)) {			return IE5_5;		}		return OTHER;	}	private static boolean regex(String regex, String str) {		Pattern p = Pattern.compile(regex, Pattern.MULTILINE);		Matcher m = p.matcher(str);		return m.find();	}}class IpUtils {	public static String getIpAddr(HttpServletRequest request) {		String ip = request.getHeader("X-Forwarded-For");		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {			ip = request.getHeader("Proxy-Client-IP");		}		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {			ip = request.getHeader("WL-Proxy-Client-IP");		}		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {			ip = request.getHeader("HTTP_CLIENT_IP");		}		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {			ip = request.getHeader("HTTP_X_FORWARDED_FOR");		}		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {			ip = request.getRemoteAddr();		}		return ip;	}}

在actionContext.xml文件中加入bean配置：

之后配置action配置

   	
        
        	
     {1}    	
        	        
      image/jpeg   	        
      bis	        
      	        
      	        
      	        
             
         
    
   

其中注意，namespace要加入“/”，否则输入地址“http://xxx/images/abc.jpg”则无法找到，平配置意思为地址路径为“http://xxx/images/”开头的，已“.jpg”结尾的所有的请求都转为处理。

例如：“http://xxx/images/abc.jpg”并将“imgPath”作为参数调用action的方法

inputName指定为action的文件流的名称

下载的文件名、缓冲区大小在此不配置也可以

完成后地址栏输入“”后就可以看到成果了

转载地址：http://nhlpi.baihongyu.com/