页面中显示ftp中的图片

package com.sais.inkaNet.common.displayImage;

import com.opensymphony.xwork2.ActionSupport;

import com.sais.inkaNet.base.util.FtpImageDisplay;
import com.sais.inkaNet.base.util.PropertiesUtil;

import org.apache.log4j.Logger;
import org.apache.struts2.ServletActionContext;

import javax.servlet.http.HttpServletResponse;

public class DisplayImageAction extends ActionSupport {
	private static final long serialVersionUID = 1L;
	private static final Logger log = Logger.getLogger(DisplayImageAction.class);
    /**
     * <p>属性描述: [要访问的图片url]</p>
     */
    private String imageUrl;

    /**
     * <p>属性描述: [ftp ip地址]</p>
     */
    private String ip = PropertiesUtil.getSetting("ftp.ip", "");

    /**
     * <p>属性描述: [ftp密码]</p>
     */
    private String password = PropertiesUtil.getSetting("ftp.password", "");

    //---------ftp---------
    /**
     * <p>属性描述: [用户名]</p>
     */
    private String username = PropertiesUtil.getSetting("ftp.username", "");

    /**
     * <p>方法描述: [获得ftp中的图片用于页面显示]</p>
    *
    * @return 返回结果的说明
    *
    * @throws Exception 抛出异常的原因
    */
    @Override
    public String execute() throws Exception {
    	log.info("-->获得ftp图片,imageUrl："+imageUrl);
        /**
                1.+ 表示空格（在 URL 中不能使用        空格）    %20
                2./ 分隔目录和子目录                                         %2F
                3.? 分隔实际的 URL 和参数                                %3F
                4.% 指定特殊字符                                              %25
                5.# 表示书签                                                     %23
                6.& URL 中指定的参数间的分隔符                       %26
                7.@     %40
         */

    	imageUrl = imageUrl.contains("\\") ? imageUrl.replace("\\", "%2F") : imageUrl;
        imageUrl = imageUrl.contains("/") ? imageUrl.replace("/", "%2F") : imageUrl;
        password = password.contains("@")?password.replace("@", "%40"):password;
        HttpServletResponse response = ServletActionContext.getResponse();
        FtpImageDisplay.getFtpImage(username, password, ip, imageUrl, response);

        return NONE;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

package com.sais.inkaNet.base.util;

import org.apache.log4j.Logger;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import java.net.URL;
import java.net.URLConnection;

import javax.servlet.http.HttpServletResponse;
public class FtpImageDisplay {
    /**
     * <p>属性描述: [声明日志]</p>
     */
    private static final Logger log = Logger.getLogger(FtpImageDisplay.class);

    /**
     * <p>方法描述: [从ftp中获得图片流返给页面]</p>
    *
    * @param username 用户名
    * @param password 密码
    * @param ftpUrl  ftp的url
    * @param fileUrl 文件路径
    * @param response Response对象
    */
    public static void getFtpImage(String username, String password, String ftpUrl, String fileUrl,
                                   HttpServletResponse response) {
        InputStream isr = null;
        OutputStream out = null;
        URL u  = null;
        try {
            if ((fileUrl != null) && !"".equals(fileUrl)) {
                response.setHeader("Content-Type", "image/png"); //response.setContentType("image/*"); // 设置返回的文件类型 

                out = response.getOutputStream();

                StringBuffer sb = new StringBuffer("ftp://");

                sb.append(username + ":");
                sb.append(password + "@");
                sb.append(ftpUrl + "/" + fileUrl);
                u = new URL(sb.toString());
                URLConnection urlconn = u.openConnection();
                isr = urlconn.getInputStream();

                int len = urlconn.getContentLength();
                int i = len;
                int c;

                while (((c = isr.read()) != -1) && (--i > 0)) {
                    out.write(c);
                }

                log.info("获取ftp图片" + fileUrl);
            } else {
                log.warn("所要显示的图片路径为空");
            }
        } catch (Exception e) {
        	log.error(e.getMessage());
        } finally {
            try {
            	
                if (isr != null) {
                    isr.close();
                }

                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {
            	log.error(e.getMessage());
            }
        }
    }
}