java struts2模拟百度百科图片中的防盗链设置方法实例代码。
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
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struts.i18n.encoding = UTF-8
struts.action.extension = html,jpg
struts.devMode=true
struts.custom.i18n.resources=messageResource
struts.locale=zh_CN
struts.multipart.saveDir=javax.servlet.context.tempdir
struts.ui.theme=simple
struts.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
[java] view plaincopyprint?
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：
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<bean id=”test” class=”test.com.eca.service.Test”
parent=”baseAction” scope=”prototype”>
</bean>
之后配置action配置
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<package name=”test” extends=”struts-default” namespace=”/images”>
<!– 测试图片权限管理 –>
<action name=”*” class=”test” method=”testImg”>
<param name=”imgPath”>{1}</param>
<result type=”stream”>
<param name=”contentType”>image/jpeg</param>
<param name=”inputName”>bis</param>
<!– 指定下载的文件名 –>
<!–<param name=”contentDisposition”>filename=”wjc_lgo.jpg”</param>–>
<!– 指定下载文件时的缓冲大小 –>
<!–<param name=”bufferSize”>1024</param>–>
</result>
</action>
</package>
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“http://192.168.2.15:5050/ecs/images/tomcat.jpg”后就可以看到成果了